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Diversity of deep-sea fishes of the Easter Island Ecoregion
Abstract
The Easter Island Ecoregion is in the center of the South Pacific gyre and experiences ultra-oligotrophic conditions that could make it highly susceptible to global change and anthropogenic activities, so it is imperative that these regions are characterized and studied so that conservation and sustainable management strategies can be developed. From the few studies from the region, we know that the coastal areas are relatively depauperate and have relatively high rates of endemism. Here, we present a brief report from the first video observations from this region of the deep fish fauna from ROV exploration of benthic communities from 157 to 281 m and baited drop-camera videos from 150 to 1850 m. We observed a total of 55 fish species from the ROV and Drop-Cam surveys; nine could not be assigned family level or lower, 26 were observed in the ROV surveys, 29 were observed in the Drop-Cam surveys, nine were observed with both survey methods, at least six species are potentially new to science, and nine species were observed at deeper depths than previously reported. These new reports may be indicative of the unique oceanographic conditions in the area and the relative isolation of the communities that have provided opportunity for the evolution of new species and favorable conditions for range expansion. In contrast, these new reports may be indicative of the severe undersampling in the south Pacific at mesopelagic depths. The prevalence of potentially new species suggests that the region likely harbors a wealth of undiscovered biodiversity.
... This lower diversity is attributed to the island's geographical isolation, small size with low habitat diversity, low productivity of surrounding waters, young geological age and high latitude (Randall & Cea, 2011). Nevertheless, increased scientific effort in the area has expanded the scientifically recorded number of inshore and epipelagic fishes from c. 30 to 179 species in only 40 years (e.g., Easton et al., 2017Easton et al., , 2018Hernández et al., 2015;Morales et al., 2019a;Randall & Cea, 2011). For a summary of the research conducted in the region see Paredes et al. (2019). ...
... Determining whether or not a newly scientifically recorded species is a recent arrival, however, is not always clear. As Rapa Nui is historically understudied compared to other islands in the Pacific Ocean (likely a result of its remote location and logistical constraints), recent first records may be a product of increased research efforts and new observational methods (i.e., the present study; Hernández et al., 2015;Easton et al., 2017Easton et al., , 2018Morales et al., 2019a;Shepherd et al., 2020) rather than species re-distributions (Shoo et al., 2006). An increase in species first records corresponding to increased survey effort has been reported in other understudied locations such as the nearby Pitcairn ...
... Highly mobile species are particularly subject to such biases as their low densities and high movement capacities may contribute to false absences in sampling regimes (Hill et al., 2016). The use of various methodologies, such as ROVs (Easton et al., 2017) is possible that this species may also be present at Rapa Nui as a third morphotype, although not recorded scientifically. ...
We report new records of the fisheries-harvested subtropical greater amberjack Seriola dumerili for the south-east Pacific Ocean. Previously, only one species of Seriola (the yellowtail amberjack Seriola lalandi) was scientifically recorded for Rapa Nui (also known as Easter Island) despite local fishers’ asserting that three Seriola morphotypes are found in the region. Here we present the first ‘scientific record’ of what could be a pre-existing (albeit transient) species of the Rapa Nui ecoregion. Establishing the existing range limits of commercially and ecologically valuable species is key for observing climate-driven distribution shifts, and the inclusion of traditional ecological knowledge is likely to be particularly important in areas with relatively fewer scientific surveys.
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... Rapa Nui (Easter Island) is one of the most isolated islands in the world, located approximately 3,700 km west of Chile and 2,000 km from the nearest inhabited island, Pitcairn (Randall and Cea, 2010;Easton et al., 2017). The Rapa Nui fish fauna exhibits a very low overall diversity (Friedlander et al., 2013;Easton et al., 2017); nevertheless, it presents the second-highest endemism in both shallow-water and deepsea fishes in the Indo-Pacific, with nearly 22% of the shore fishes being endemic (Randall and Cea, 2010;Friedlander et al., 2013). ...
... Rapa Nui (Easter Island) is one of the most isolated islands in the world, located approximately 3,700 km west of Chile and 2,000 km from the nearest inhabited island, Pitcairn (Randall and Cea, 2010;Easton et al., 2017). The Rapa Nui fish fauna exhibits a very low overall diversity (Friedlander et al., 2013;Easton et al., 2017); nevertheless, it presents the second-highest endemism in both shallow-water and deepsea fishes in the Indo-Pacific, with nearly 22% of the shore fishes being endemic (Randall and Cea, 2010;Friedlander et al., 2013). Recent genetic studies have revealed that Rapa Nui is an endemism hotspot: a location for the emergence of small-range endemic fishes (likely resulting from founderevent speciation), a route of dispersion for larger-range endemics, and a stepping stone for the diversification of some groups (Delrieu-Trottin et al., 2019). ...
... Although ichthyological surveys in the area date back to the early twentieth century, there have been relatively few surveys of fish communities living at depths greater than 40 m (Easton et al., 2019). Those that have occurred indicate that species richness is surprisingly high on MCEs, but overall MCE fish diversity at Rapa Nui remains unknown (Friedlander et al., 2013;Wieters et al., 2014;Easton et al., 2017Easton et al., , 2019. This combination of isolation, speciation from founder events, and lack of exploration makes Rapa Nui a fascinating location to study the biodiversity of MCEs and its links to that of shallow reefs. ...
... Rapa Nui (Easter Island) is one of the most isolated islands in the world, located approximately 3,700 km west of Chile and 2,000 km from the nearest inhabited island, Pitcairn (Randall and Cea, 2010;Easton et al., 2017). The Rapa Nui fish fauna exhibits a very low overall diversity (Friedlander et al., 2013;Easton et al., 2017); nevertheless, it presents the second-highest endemism in both shallow-water and deepsea fishes in the Indo-Pacific, with nearly 22% of the shore fishes being endemic (Randall and Cea, 2010;Friedlander et al., 2013). ...
... Rapa Nui (Easter Island) is one of the most isolated islands in the world, located approximately 3,700 km west of Chile and 2,000 km from the nearest inhabited island, Pitcairn (Randall and Cea, 2010;Easton et al., 2017). The Rapa Nui fish fauna exhibits a very low overall diversity (Friedlander et al., 2013;Easton et al., 2017); nevertheless, it presents the second-highest endemism in both shallow-water and deepsea fishes in the Indo-Pacific, with nearly 22% of the shore fishes being endemic (Randall and Cea, 2010;Friedlander et al., 2013). Recent genetic studies have revealed that Rapa Nui is an endemism hotspot: a location for the emergence of small-range endemic fishes (likely resulting from founderevent speciation), a route of dispersion for larger-range endemics, and a stepping stone for the diversification of some groups (Delrieu-Trottin et al., 2019). ...
... Although ichthyological surveys in the area date back to the early twentieth century, there have been relatively few surveys of fish communities living at depths greater than 40 m (Easton et al., 2019). Those that have occurred indicate that species richness is surprisingly high on MCEs, but overall MCE fish diversity at Rapa Nui remains unknown (Friedlander et al., 2013;Wieters et al., 2014;Easton et al., 2017Easton et al., , 2019. This combination of isolation, speciation from founder events, and lack of exploration makes Rapa Nui a fascinating location to study the biodiversity of MCEs and its links to that of shallow reefs. ...
A new species of Chromis (Teleostei: Pomacentridae) is described from three specimens collected at 90 m depth in a
mesophotic coral ecosystem at Rapa Nui, Chile. Chromis mamatapara, new species, can be distinguished from its
congeners by the following combination of characters: dorsal-fin rays XIV,13–14; pectoral-fin rays 18–19, third from top
of fin longest; tubed lateral-line scales 18; total gill rakers on first arch 30–32; vertebrae 11þ15; and by coloration of
living specimens, especially the presence of a single, pronounced, white spot, roughly the same diameter as the orbit,
located where the posterior base of the dorsal fin intersects the caudal peduncle. The most similar DNA barcode
(mitochondrial COI gene), among those available, is Chromis tingting from Japan (3.5% uncorrected divergence);
however, C. mamatapara, new species, also superficially resembles other species for which sequences are unavailable for
comparisons, including C. okamurai from Japan and C. struhsakeri from Hawaii. Due to the high geographic isolation and
consequently high endemism in the Rapa Nui region, we believe that C. mamatapara, new species, is endemic to
mesophotic ecosystems of Rapa Nui, Isla Salas y Gomez, and nearby seamounts, a discovery that contributes to the high ´
endemism of the region and thus the need for conservation efforts.
... In the Pacific, most MCE studies have been on communities of the tropical North Pacific and more recently the Indo-West Pacific (Bridge et al. 2012;Kahng et al. 2014;Pyle et al. 2016). Studies specifically focused on MCEs in the southeastern Pacific began with exploratory surveys (e.g., Friedlander et al. 2013;Easton et al. 2017) of the Easter Island Ecoregion (EIE), which includes the oceanic islands of Rapa Nui (RN, also known as Easter Island) and Salas y Gómez (SyG) and the surrounding seamounts. In the southeast Pacific ( Fig. 27.1a), potential habitat for corals could extend southward along the continental coast of Ecuador, Peru, and Chile to ~30° S ( Fig. 27.1b); however, zooxanthellate corals are unlikely to inhabit much of the subtropical coast south of ~23° S due to sea surface temperatures of <15 °C. ...
... Since 2000 (Friedlander et al. 2013;Easton et al. 2017), developed by the National Geographic Society, and rotary time-lapse video systems. The most recent surveys at RN were conducted by technical divers to ~95 m in March 2017 and by ROV to ~300 m by Oceana Chile and ESMOI researchers in April 2017 to study the distribution and biodiversity of MCEs. ...
... The peak of the seamount Pukao (~160 m), located ~85 km west of RN (see Fig. 1 in Easton et al. 2018), is riddled with large rocky outcrops (<5 m vertical relief) surrounded by sand and isolated loose rocks and rhodolith beds ( Fig. 27.6b, c); exposed rock is covered by CCA and occasional dense patches of Stichopathes. Likewise, a subsurface peak of RN (see Fig. 1 in Easton et al. 2017), known as the fishing grounds Apolo, has a similar habitat to Pukao but with less sand, likely due to its smaller summit area. ...
In Chile, light-dependent benthic taxa have been observed to ~280 m with the presence of zooxanthellate cnidarians forming mesophotic coral ecosystems (MCEs) to depths of at least 120 m at Rapa Nui (Easter Island) and Salas y Gómez. Evidence from dredge samples suggests MCEs in the southeast Pacific once extended along the Salas y Gómez Ridge as far east as ~85° W, but MCEs in Chile were virtually unexplored prior to 2010. Despite providing critical structural habitat for numerous flora and fauna, including commercially important fishes, basic information about their geographic distribution and community structure are lacking. Here, we review the state of knowledge on these communities and present preliminary results from the most recent surveys at Rapa Nui. Surveys at mesophotic depths (30–280 m) have revealed ecosystems dominated by crustose coralline algae with occasional patches of rhodoliths, undiscovered biodiversity, the first reports of wide-ranging Pacific species, and reports of potential new species in multiple taxa including fishes and echinoderms. Preliminary observations suggest fish communities change with depth and time of day, some habitats support commercially important and juvenile fishes, and MCEs and fisheries at Rapa Nui are in decline due to local, artisanal fishing practices. The recent designation of no-take marine parks in Chile may help to conserve these habitats, but additional information is required to support management decisions and future conservation efforts at Rapa Nui, Salas y Gómez, and seamounts within the Chilean Exclusive Economic Zone.
... Rapa Nui (Easter Island) is the most isolated inhabited island in the Indo-Pacific, located approximately 3,700 km west of Chile and 2,000 km from the nearest inhabited island, Pitcairn (Randall and Cea 2010;Easton et al. 2017). Due to the isolation, the fish fauna exhibits the highest degree of local and regional endemism in both shallowwater and deep-sea fishes in the Indo-Pacific, and very low overall diversity (Friedlander et al. 2013;Easton et al. 2017). ...
... Rapa Nui (Easter Island) is the most isolated inhabited island in the Indo-Pacific, located approximately 3,700 km west of Chile and 2,000 km from the nearest inhabited island, Pitcairn (Randall and Cea 2010;Easton et al. 2017). Due to the isolation, the fish fauna exhibits the highest degree of local and regional endemism in both shallowwater and deep-sea fishes in the Indo-Pacific, and very low overall diversity (Friedlander et al. 2013;Easton et al. 2017). Nearly 22% of the shore fishes of Easter Island are endemic (Randall and Cea 2010;Friedlander et al. 2013). ...
... Nearly 22% of the shore fishes of Easter Island are endemic (Randall and Cea 2010;Friedlander et al. 2013). Although ichthyological studies since the 1980's have greatly expanded the knowledge of fish diversity in this ecoregion, there have been relatively few surveys of fishes at depths greater than 40 m (Friedlander et al. 2013;Wieters et al. 2014;Easton et al. 2017). Recent advances in technical mixed-gas rebreather diving are now allowing scientists to safely document small, active, cryptic, and demersal fishes in ways that have been previously impossible (Pyle 2000;Pyle et al. 2016;Rocha et al. 2017). ...
A new species of the perchlet genus Plectranthias is herein described from a single specimen found at Rapa Nui (Easter Island) in the South Pacific. Plectranthiasahiahiata sp. n. was collected at a depth of 83 m in a mesophotic coral ecosystem at Rapa Nui. The main difference between Plectranthiasahiahiata and other members of the genus is higher fin-ray counts (X, 18 dorsal; 18 pectoral) and its distinctive coloration. Compared to the three other known eastern South Pacific species, P.ahiahiata has more dorsal-fin rays, more pectoral-fin rays, fewer tubed lateral-line scales, fewer gill rakers, a longer head relative to SL, a very short first dorsal spine relative to SL, and a short third anal spine relative to SL. Plectranthiasahiahiata is distinguished from western Pacific species, by having more dorsal- and pectoral-fin rays. The closest relative based on genetic divergence (with 12.3% uncorrected divergence in the mitochondrial COI gene) is Plectranthiaswinniensis , a widely distributed species, suggesting important links between Rapa Nui and western Pacific islands. This new species adds to the high endemism of the Rapa Nui ichthyofauna, and is further evidence of the importance of mesophotic reefs as unique communities.
... Furthermore, these deep-sea explorations have documented numerous species that are new to science ( Parin & Shcherbachev 1982 ;Anderson & Johnson 1984 ;Parin & Kotlyar 1989 ;Parin & Sazonov 1990 ;Parin 1992 ;Garth 1992 ;McCosker & Parin 1995 ;Galil & Spiridonov 1998 ;Anderson & Springer 2005 ;Motomura et al. 2012 ;Schwarzhans 2014 ;Easton et al. 2019 ;. For instance, limited remotely operated vehicle (ROV) surveys at 160-280 m depths recorded six new species of fishes ( Easton et al. 2017 ), as well as two new genera of echinoderms . This high rate of new species discoveries indicates that the marine fauna of this region still contains a large number of undiscovered species, which represent an enormous opportunity for future scientific exploration and conservation ( Reiswig & Araya 2014 ;Easton et al. 2017 ) . ...
... For instance, limited remotely operated vehicle (ROV) surveys at 160-280 m depths recorded six new species of fishes ( Easton et al. 2017 ), as well as two new genera of echinoderms . This high rate of new species discoveries indicates that the marine fauna of this region still contains a large number of undiscovered species, which represent an enormous opportunity for future scientific exploration and conservation ( Reiswig & Araya 2014 ;Easton et al. 2017 ) . As an example, living individuals of the gastropod Architectonica karsteni were recently found on seamounts of the Nazca Ridge ( Asorey et al. 2020 ). ...
... known as Easter Island). The ridges consist of over 110 seamounts, many of which peak close to the surface and host photosynthetic communities (Easton et al., 2017;Wagner et al., 2021a). The ridges host ecosystems with some of the highest rates of marine endemism in the world and are a haven to over 80 threatened or endangered species (reviewed in Wagner et al., 2021b). ...
... Reef-building corals in shallow water are a good example of this mixed influence, as the ridges contain some coral species that are related to those found in Colombia, Ecuador, and Panama (Glynn et al., 2007;Easton et al., 2019). It is important to highlight that the Salas y Goḿez and Nazca ridges are the only place in the Southeast Pacific, and one of the few places in ABNJ globally, where seamounts peak in waters shallow enough (<200m) to host photosynthetic reef-building corals (CBD, 2017;Easton et al., 2017;Wagner et al., 2020;Wagner et al., 2021a;Wagner et al., 2021b;Zapata-Hernańdez et al., 2021). These reef-building corals in turn are important ecosystem engineers that create habitat for a wide variety of associated species (Wagner et al., 2020;Georgian et al., 2021). ...
Connectivity is essential to consider in area-based marine conservation measures because it greatly impacts vital ecological processes (e.g., recycling nutrients, regulating temperature, sequestering carbon, and supporting the life cycle of species). However, it is generally not well studied or integrated into conservation measures, particularly in the Southeast Pacific. This region is home to the Salas y Gómez and Nazca ridges, two adjacent seamount chains that stretch between the Peruvian coast and Rapa Nui (i.e., Easter Island). The area has been recognized for its exceptional natural and cultural significance as well as one of the most important global areas to protect. However, over 73% of the ridges are in areas beyond national jurisdiction, where they are unprotected and under threat. This study provides a synthesis of what we know about connectivity in the Salas y Gómez and Nazca ridges and provides practical recommendations for integrating this knowledge into conservation and management measures for the region. While data on connectivity is still limited, it should not constrain the development of conservation measures, which should be co-designed and co-developed, leveraging the expertise of international working groups throughout the region. Due to their high rates of endemism, as well as importance as migratory corridors, enacting large-scale conservation measures would address important conservation considerations for both connectivity and endemism. Enacting such large-scale conservation measures would not only elevate the Salas y Gómez and Nazca ridges as an exemplary case study, providing lessons for other marine regions seeking to implement similar measures, but could also help raise awareness on the severity of externally originating threats like climate change and plastic pollution to global audiences.
... Surveys within the EIE have revealed the presence of a variety of often heterogenous substrates (i.e., rocky, sandy and rhodoliths bottoms) (Easton et al., 2017Mecho et al., 2019;Shepherd et al., 2020) that provide a wide variety of habitats for black whip corals. The presence of these whip coral gardens seems to contribute to increasing the availability of habitat and resources for other species. ...
... Our study supports previous reports that whip black coral populations within the EIE provide important habitat and nursery grounds for a wide variety of organisms (e.g., ophiuroids, echinoids, and potentially new species of fishes). Easton et al. (2017Easton et al. ( , 2018 and Shepherd et al. (2020) documented the presence of yellowfin soldierfish (Myripristis chryseres) and juveniles of Chromis mamatapara and butterflyfishes (Prognathodes sp.) in association with whip black corals, highlighting the potential habitat preference of these species in whip coral gardens of Pukao seamount and Rapa Nui at 90-230 m. In our study, some invertebrates (e.g., sea star: Goniasteridae and gastropod: unidentified Coralliophilinae) were observed preying on the tissues of whip corals. ...
One of the main priorities of marine scientific research is to provide practical information and guidance for biodiversity conservation and management. In this context, the identification of key and fragile habitat-forming species is particularly important. Despite their ecological importance, whip corals in the order Antipatharia remain poorly studied around the world, and especially in the South Pacific. During recent expeditions to explore mesophotic and deep benthic habitats around Rapa Nui (Easter Island), dense assemblages of whip black corals were observed in situ. We here report the first detailed description of the distribution and abundance of these black coral assemblages and their associated fauna and habitat. These descriptions were based on analysis of video surveys collected on 67 remotely operated vehicle dives conducted in 2014 through 2019 at three sites (Pukao seamount, Apolo peak, and Rapa Nui Island shelf and slope) within the Easter Island Ecoregion at depths between 50 and 330 m. At least four morphotypes (yellow, red, white/orange, and Pukao) of unbranched black corals were detected. Each morphotype had polyps arranged in a single row on only one side of the corallum, a diagnostic morphological character currently assigned to the antipatharian genus Stichopathes. Samples of the yellow and red morphotypes were collected and studied using morphological and molecular techniques. These analyses indicate that the genus Stichopathes is not monophyletic and requires further revisions, a conclusion that is consistent with previous studies. Extensive fields of whip black corals, primarily of the yellow and red morphotype, were present at 28 sites from 60 to 245 m on rocky substrates, coarse sand, or rhodoliths. Densities of these assemblages per frame were up to 58.2 ± 5.2 colonies m −2 (average: 13.2 ± 0.8), which represent some of the highest reported densities for black corals to date. Numerous faunal groups, including ophiuroids, echinoids, and fishes, were associated with these whip black
... Furthermore, these deep-sea explorations have documented numerous species that are new to science [9,20,[50][51][52][53][54][55][56][57][58][59][60][61][62]. For instance, recent remotely operated vehicle (ROV) surveys at 160-280 m depths recorded six new species of fishes [63], as well as two new genera of echinoderms [14]. This high rate of new species discoveries indicates that the marine fauna of this region still contains a large number of undiscovered species, which represent an enormous opportunity for future scientific exploration and conservation [10,63,64]. ...
... For instance, recent remotely operated vehicle (ROV) surveys at 160-280 m depths recorded six new species of fishes [63], as well as two new genera of echinoderms [14]. This high rate of new species discoveries indicates that the marine fauna of this region still contains a large number of undiscovered species, which represent an enormous opportunity for future scientific exploration and conservation [10,63,64]. As an example, live individuals of the gastropod Architectonica karsteni were recently found on seamounts of the Nazca Ridge [65]. ...
The Salas y Gómez and Nazca ridges are two seamount chains of volcanic origin, which include over 110 seamounts that collectively stretch across over 2,900 km in the southeastern Pacific. Ecosystems in this region are isolated by the Atacama Trench, the Humboldt Current System, and an extreme oxygen minimum zone. This isolation has produced a unique biodiversity that is marked by one of the highest levels of marine endemism on Earth. These areas also provide important habitats and ecological stepping stones for whales, sea turtles, corals, and a multitude of other ecologically important species, including 82 species that are threatened or endangered. Recent explorations in this region have documented one of the deepest light-dependent marine ecosystems on Earth, as well as numerous species that are new to science. Waters surrounding the Salas y Gómez and Nazca ridges are mostly located in areas beyond national jurisdiction (ABNJ), with smaller portions located in the national waters of Chile and Peru. Within this region, Chile has already protected all the ridge features that fall within its jurisdiction, and Peru is evaluating a proposal that would protect the seafloor that falls within its national waters. However, all of the ABNJ in the region, which cover over 73% of the Salas y Gómez and Nazca ridges, are unprotected and under threat from a variety of stressors, including climate change, plastic pollution, overfishing, and potential deep-sea mining in the future. Importantly, fishing and other commercial activities are at low levels in international waters of this region, so there is a time-sensitive opportunity to protect its unique natural and cultural resources before they are degraded. This study provides a synthesis of the relevant science that has been conducted on the Salas y Gómez and Nazca ridges, and discusses the opportunities and challenges for protecting this unique region via existing sectoral organizations and through the emerging international agreement on biodiversity beyond national jurisdiction (BBNJ). Given its exceptional natural and cultural significance, the Salas y Gómez and Nazca ridges should be comprehensively protected from exploitation, pollution and other anthropogenic threats using the best available conservation measures.
See: https://www.sciencedirect.com/science/article/pii/S0308597X20310289
... fishing) in shallow waters. Easter Island has been understudied in comparison with other islands in the Pacific Ocean, and studies at deeper depths are even more limited ( Easton et al., 2017). S. lalandi and P. cheilio were recorded at ~280 m and ~170 m respectively, using a remotely operated vehicle and Drop-Cams around Easter Island and the surrounding seamounts (Easton et al., 2017). ...
... Easter Island has been understudied in comparison with other islands in the Pacific Ocean, and studies at deeper depths are even more limited ( Easton et al., 2017). S. lalandi and P. cheilio were recorded at ~280 m and ~170 m respectively, using a remotely operated vehicle and Drop-Cams around Easter Island and the surrounding seamounts (Easton et al., 2017). The occurrence of inshore species at deeper depths could also suggest that deeper habitats are being used as a refuge from natural and anthropogenic influences. ...
Reef fishes are an important component of marine biodiversity, and changes in the composition of the assemblage structure may indicate ecological, climatic, or anthropogenic disturbances. To examine spatial differences in the reef fish assemblage structure around Easter Island, eight sites were sampled during autumn and summer 2016–2017 with baited remote underwater video systems.
To determine seasonal changes, quarterly (seasonal) sampling was conducted at five of those eight sites. Fifteen pelagic species of fishes were recorded during this study, some of which have not previously been recorded in scuba surveys, including the Galapagos shark ( Carcharhinus galapagensis , Snodgrass & Heller, 1905) and tunas (Scrombidae).
Significant spatial and seasonal differences were found in the fish assemblage. Fish assemblages from the south coast differed significantly from those along the west and east coasts, mainly due to the occurrence of top predators. Winter differed from other seasons, especially along the south coast where the island is more exposed to large oceanic swells and winds from Antarctica.
Owing to the variety and high relative abundance of species recorded during this survey, baited remote underwater video systems seemed to be an effective method for studying top predators at Easter Island. The identification of priority zones for the protection of top predator species represents an important contribution of this study, in order to develop management and conservation strategies to be implemented in the newly created Rapa Nui multiple uses coastal marine protected areas.
... The objectives of this study were: (1) to describe the echinoderm community at two sites of the EIE and (2) to explore biogeographic affinities between the observed assemblages and those of the eastern and western South Pacific. Considering the higher degree of endemism reported for the deep communities of the Nazca Ridge and EIE (Friedlander et al. 2013;Easton et al. 2017) and the distance (i.e., isolation) among potential mesophotic habitats in the EIE, we expected similar high rates of endemism in the EIE mesophotic echinoderms. We hypothesized that fauna on the Nazca Ridge and in the EIE was more similar to that of species in West Pacific than those in the Eastern Pacific as found in other studies of southeast Pacific fauna (i.e., echinoderms ;Fell 1974;Parin et al. 1997). ...
... Numerous morphospecies have also not been reported for neighboring areas, such as Pitcairn (Friedlander et al. 2014) or Desventuradas Islands (Parin et al. 1997), emphasizing how limited our basic knowledge of this group is, not only the EIE, but also the Southeast Pacific. Studies undertaken on other EIE fauna (e.g., fishes, macroalgae) likewise revealed several potential new species and first records for the region (Easton et al. 2017;Santiañez et al. 2018), supporting our observations that several of the reported morphospecies may not only be new records for the region but also could be potential new genera and species. Moreover, when comparing echinoderm assemblages reported from shallow EIE waters (< 30 m) ) with our results for mesophotic depths (~ 160-280 m), we observed only five species in common: Clypeaster reticulatus, Tripneustes gratilla, Pseudoboletia indiana, Ophidiaster easterensis and "Black Diadema". ...
The Easter Island ecoregion (EIE) is one of the most remote marine areas of the world and encompasses a vast and fragile ecosystem including oceanic islands and seamounts. In January 2014 and March 2016, a remotely operated vehicle was used to explore a subsurface peak off Easter Island (27.23°S, 109.48°W) and a seamount (26.92°S, 110.26°W), respectively located 10 km southwest and 98 km west of the island. More than 950 echinoderms were observed in the 5 h of video recorded during the seven dives conducted at depths between ~ 160 and 280 m. The communities of echinoderms observed at these depths markedly differed from those reported for shallower waters near Easter Island. Of the 20 morphospecies reported in the present study, only 5 were previously reported in the EIE. One species, six genera, and three families were reported for the first time in this area, and two new genera were discovered and described. A preliminary biogeographic analysis suggests affinities between the observed echinoderms and those of the West Pacific. These findings highlight the uniqueness of these assemblages and, therefore, the importance of considering them in the establishment of effective management strategies for these communities, which are within the Rapa Nui marine-protected area created in 2017.
... Rapa Nui (Easter Island) is the most isolated inhabited island in the Indo-Pacific, located approximately 3,700 km west of Chile and 2,200 km from the Nazca Ridge (Randall & Cea 2010, Easton et al. 2017). Due to this isolation, the Rapa Nui fish fauna exhibits the second-highest degree of endemism in the Indo-Pacific (after the Hawaiian Islands), with up to 21.7% among shorefishes, but has very low overall diversity (Randall & Cea 2010). ...
... Due to this isolation, the Rapa Nui fish fauna exhibits the second-highest degree of endemism in the Indo-Pacific (after the Hawaiian Islands), with up to 21.7% among shorefishes, but has very low overall diversity (Randall & Cea 2010). Two recent papers report a much higher endemism rate of 40.3% ( Friedlander et al. 2013, Easton et al. 2017, however, this is the percentage of endemism represented in the dominant observed reef fish assemblages rather than the entire shorefish fauna known to occur at Rapa Nui. Although ichthyological studies since the 1980s have greatly expanded the knowledge of fish diversity in this ecoregion, there have been few surveys of fishes at depths greater than 40 m ( DiSalvo et al. 1988, Hubbard & Garcia 2003. ...
A new species in the anthiadine genus Luzonichthys Herre, 1936 is described from a specimen collected at a depth of 83 m in a mesophotic coral ecosystem at Rapa Nui (Easter Island). Luzonichthys kiomeamea n. sp. can be distinguished from the 7 other valid Luzonichthys species by anal-fin and pectoral-fin counts, the number of lateral-line scales, the number and arrangement of gill rakers, and coloration pattern. Mitochondrial DNA sequencing shows that the new species is more than 11% divergent in the COI sequence (and about equally distant) from Luzonichthys waitei, L. seaver, L. earlei (Hawai'i), and L. aff. earlei (Coral Sea). Given the isolation of the island, and the uniqueness of its fish fauna, we suspect that the new species is endemic to the mesophotic reefs of Rapa Nui.
... Some work documenting fishes in MCEs has involved the use of various remote forms of underwater camera systems, such as drop and towed camera systems (Blyth-Skyrme et al. 2013;Easton et al. 2017), remotely operated vehicles (ROVs; Pereira-Filho et al. 2011;Blyth-Skyrme et al. 2013;Bryan et al. 2013;Reed et al. 2017;Ajemian et al. 2015a, b;Cánovas-Molina et al. 2016;Simon et al. 2016;Streich et al. 2017;Easton et al. 2017;Armstrong et al. 2019), and baited remote underwater video stations (BRUVS; Blyth-Skyrme et al. 2013;Pearson and Stevens 2015;Andradi-Brown et al. 2016Lindfield et al. 2016;Asher et al. 2017a, b). Autonomous underwater vehicles (AUVs) have also been utilized for MCE research, but they have mostly focused on characterizing sessile benthic fauna (Armstrong and Singh 2012;Armstrong et al. 2011Armstrong et al. , 2019Bridge et al. 2011). ...
... Some work documenting fishes in MCEs has involved the use of various remote forms of underwater camera systems, such as drop and towed camera systems (Blyth-Skyrme et al. 2013;Easton et al. 2017), remotely operated vehicles (ROVs; Pereira-Filho et al. 2011;Blyth-Skyrme et al. 2013;Bryan et al. 2013;Reed et al. 2017;Ajemian et al. 2015a, b;Cánovas-Molina et al. 2016;Simon et al. 2016;Streich et al. 2017;Easton et al. 2017;Armstrong et al. 2019), and baited remote underwater video stations (BRUVS; Blyth-Skyrme et al. 2013;Pearson and Stevens 2015;Andradi-Brown et al. 2016Lindfield et al. 2016;Asher et al. 2017a, b). Autonomous underwater vehicles (AUVs) have also been utilized for MCE research, but they have mostly focused on characterizing sessile benthic fauna (Armstrong and Singh 2012;Armstrong et al. 2011Armstrong et al. , 2019Bridge et al. 2011). ...
Fishes are an important component of coral reef ecosystems, and in comparison to other marine phyla, the taxonomy of fishes is relatively robust. Some of the earliest explorations of mesophotic coral ecosystems (MCEs) involving both submersibles and rebreather diving focused on fishes. Since 1968, over 400 publications have documented fishes on MCEs, ~75% of which were published since 2011. Most fish species inhabiting MCEs belong to families and genera typical of shallow coral reefs, and many new species remain to be discovered and described. Species richness generally peaks at a depth of 30 m and declines with increasing depth. The composition of the fish communities on MCEs includes a mixture of species restricted to MCEs and species with broad depth ranges. Patterns of species turnover and composition vary depending on geographic location, ecological characteristics, and method of study. Nearly 70% of MCE fish research has occurred within the tropical western Atlantic and Hawaiʻi. Not enough is known about global distributions to infer broad biogeographical patterns, but there seems to be higher representation by endemic species and individuals on MCEs, and the eastward attenuation of diversity of shallow Pacific reefs does not appear to apply to fishes within MCEs. Analyses of nearly 900,000 occurrence records of reef fishes at depths of 1–200 m reveal patterns of diversity that are mostly consistent with controlled studies. Future work should emphasize basic exploration and documentation of diversity in under-sampled geographic regions and hypothesis-driven studies in areas where logistics facilitate MCE research.
... Visual documentation by means of ROV is an excellent alternative to investigate benthic communities at locations characterized by extremely irregular bottom structures as raising rocks that inhibit traditional bottom sampling with trawls or dredges and being inaccessible to non-technical divers . Although images often do not allow exact taxonomic descriptions, within the past years the use of underwater video revealed numerous first records, including registers of new species of fishes and invertebrates from seamounts, oceanic islands and the continental coast of Chile (Friedlander et al. 2013;Easton et al. 2017;Gorny et al. 2018). The general objective of the expedition to the interior waters of the Campana Archipelago, was to investigate the composition of benthic communities in the easternmost part of the KNR and to prove the hypothesis that species composition in the waters around the islands and next to the ocean differ in comparison to channels located much closer to the continent. ...
... Although we cannot confirm with exactitude that our specimens represent to C. cookianus or eventually a new species for science, the visual records from the Campana Archipelago is the first register of the genus Coelorinchus in the inner waters of the central region of the Chilean fjords and channels, and in a comparable shallow depth. Although underwater images sometimes do not allow exact identification at species level, it has been shown that visual observations by means of ROV and similar systems are useful tools to document marine biodiversity where traditional sampling is difficult as on seamounts and other the deep-sea environments (Easton et al. 2017). In fact, the yellow soldierfish Myripristis chryseres was detected by means of underwater video at Easter Island , and the first record of black corals attached underneath of rocks in shallow waters to the north of Coquimbo was also gained by using an ROV . ...
This is the first report of Coelorinchus cf. cookianus in comparable shallow coastal waters in the southeastern Pacific. Two individuals were filmed with a remotely operated vehicle (ROV) at 150 m of depth at the pacific entrance of the October Channel in the Campana Archipelago in central Patagonia, Chile. The specimens were identified on a video transect as macrourids by their elongate tapering tail, and the dorsal fins with two spinous rays. The fishes showed a series of regular dark saddle-like bands on the top and sides of the body from before the first dorsal fin to tip of tail. These criteria fit best with description of Coelorinchus cookianus which is described as endemic in New Zealand waters. However, two of four Coelorinchus species registered in the southeastern Pacific have widespread distributions in the southern hemisphere. Lack of sampling effort in the central Patagonian coast, including shelf and upper slope may explain why until now C. cookianus was exclusively reported in New Zealand waters.
... In contrast, seamounts may provide habitat for and enable connections among populations of deeper-dwelling species, such as M. chryseres and E. acutirostris, and therefore harbor relatively rich communities of fishes. Preliminary surveys at mesopelagic depths at Easter Island and Salas y Gómez have found relatively high richness at ~150 -300 m relative to shallow depths (<40 m) (Easton et al. 2016). The seamounts between French Polynesia and the eastern Salas y Gómez Ridge have not been surveyed, so future surveys, using advanced collection and observational technologies, are needed to evaluate the relative richness of these communities and how extensive the connection is among seamounts. ...
... Nevertheless, due to the large distance and potentially limited connectivity between M. chryseres populations of the Easter Island Ecoregion and the Indo-West Pacific, it is also possible that the observed specimens represent a genetically distinct population or a potential new species that closely resembles M. chryseres. This possibility is supported by Easter Island having a high percentage of endemic fishes and other fauna and by recent observations at similar depths of numerous potential new species of fishes that are morphologically similar to congeners in the Indo-West Pacific and Hawaiian archipelago (see Easton et al. 2016). Therefore, collection of specimens is critical for future studies of presumed M. chryseres from the Easter Island Ecoregion and connectivity among its populations. ...
Myripristis chryseres Jordan & Evermann, 1903, is recorded for the first time in the Easter Island Ecoregion. Two specimens were observed swimming along a rock cliff and entering a cavern at ∼163 m depth near the peak of Pukao seamount, located ∼85 km (46 nm) west of Easter Island. This report expands the geographic range of M. chryseres eastward by ∼3,800 km and is the first report of the species for the eastern Pacific. It is unclear whether this new record is indicative of a relatively recent range expansion or a lack of visual surveys in the region, which are especially important for surveying fishes that are less likely to be caught by line and trawls because of their behavior and the complex rocky habitats in which they live.
... The bathymetry of Rapa Nui, Pitcairn and Rapa is sloped, so shallow-reef habitats are more likely to persist across glacial cycles than shallowreef habitats within the Tuamotu Archipelago. Several recent studies have focused on marine biodiversity and associated biogeographic implications at Rapa Nui, including species inhabiting MCEs (Easton et al. 2017, Delrieu-Trottin et al. 2019, Hoeksema et al. 2019, Mecho et al. 2019, Friedlander et al. 2021, Liggens et al. 2021, Mah 2021. The results of these studies reveal patterns that are consistent (or, at least, not inconsistent) with the predictions of the HPH. ...
... In this context, the goal of the present study was to complete existing inventories of the benthic fauna of the area with the first in situ observations from the upper continental slope using underwater video images. In Chile, this technology was applied successfully in the past years to describe the benthic-demersal fauna of other deep-sea habitats such as the seamounts around the oceanic islands in the southeastern Pacific (Friedlander et al. 2013, Easton et al. 2017, Tapia et al. 2021b). ...
An autonomous lander equipped with a video camera (dropcam) was used for in situ observations of the bento-demersal macrofauna on the upper continental slope off Punta Pichalo in northern Chile, an area of permanent coastal upwelling processes, located ~70 km north of Iquique. The lander was deployed at nine stations and between 227 and 798 m of depth. According to morphological characteristics, 34 operational taxonomic units (OTUs) were identified to the lowest taxonomic level; 24 belonged to macroinvertebrates and 10 to fishes. Macroinvertebrates comprised 9 OTUs of crustaceans, seven cnidarians, and six echinoderms. Fishes included 3 OTUs of the order Chondrichthyes, 3 belonging to macrourid. Perciformes, Anguilliformes, and Alepocephaliformes were represented by one OTU each. Also, we observed one species of lanternfish (Myctophidae). Apart from the brachyuran decapod Lophorochinia parabranchia Garth, 1969 and euphausiids, all species were observed at depths greater than 560 m. The presence of one individual identified as the granulate dogfish Centroscyllium granulatum Günther, 1887 extended the known distribution range of this species about 1000 km to the north. Images taken at 795 m showed Bathyraja peruana McEachran & Miyake, 1984. Our study suggests that the upper continental slope of northern Chile harbors nearly undiscovered biodiversity, worth to be studied more intensively to complete the comparable sparse knowledge about marine biodiversity and species distribution at the continental margin in front of Chile.
... This is the fourth species description resulting from this expedition to Rapa Nui, and the sixth member of the subfamily Anthiadinae to be found at the island. Caprodon longimanus Günther, 1859, Plectranthias parini Anderson & Randall, 1991, P. ahiahiata Shepherd, Phelps, Pinheiro, Pérez-Matus & Rocha, 2018, and Luzonichthys kiomeamea Shepherd, Pinheiro, Phelps, Pérez-Matus & Rocha, 2019 are the other described Anthiadinae known from Rapa Nui; a presumed Tosanoides has also been observed with remotely operated vehicles but has yet to be captured and examined (Easton et al. 2017). These species, along with Chromis mamatapara Shepherd, Pinheiro, Phelps, Easton, Pérez-Matus & Rocha, 2020, and the new anthias presented here, appear to be restricted to MCEs, as is the case for much of the ichthyological biodiversity being revealed by scientists exploring these ecosystems Pinheiro et al. 2019). ...
Pseudanthias hangapiko sp. nov. (Teleostei, Serranidae, Anthiadinae) is herein described from three specimens collected from a depth of 83 m in a mesophotic coral ecosystem off Hanga Piko, Rapa Nui (Easter Island), Chile. Pseudanthias hangapiko sp. nov. can be distinguished from its congeners in live coloration and by the following combination of characters: dorsal-fin rays X, 17; anal-fin rays III, 8; pectoral-fin rays 16 (left side of one specimen 17); vertebrae 10+16; scales relatively large, two scales above lateral-line to base of fifth dorsal spine, and 16-17 circumpeduncular scales; gill rakers 11+23; and a slender body, with greatest body depth 3.6 (3.4-3.8) in SL. The most similar DNA barcodes (mitochondrial COI gene) are from Pseudanthias ventralis Randall, 1979 and Pseudanthias hawaiiensis Randall, 1979, with 16.8% and 17.0% uncorrected divergence, respectively. This fish is one of four new species that were documented from a pair of technical dives at a single location in Rapa Nui, emphasizing the high number of undescribed species likely still unknown in mesophotic coral ecosystems, especially in geographically remote locations. Pseudanthias hangapiko sp. nov. adds to the Rapa Nui ichthyofauna, which hosts the second-highest level of endemism in both shallow and deep-water fishes.
... The NGS deep-sea camera system has been used across a variety of different geomorphological zones and habitats ( Table 1). It has been used extensively on seamounts (e.g., Easton et al., 2017;Buglass et al., 2020), in oceanic island/archipelagos (e.g., Giddens et al., 2020), polar shelf areas (e.g., Friedlander et al., 2020) and fjordlands (Chile, Southeast Alaska; Table 1). While the first-generation landers made exploratory deployments to hadal zones in ocean trenches (e.g., Puerto Rico, Tonga and Marianas Trenches) up to 10,641 m depth, the majority of deployments made with the next-generation deep-sea camera system have been conducted in <3000 m ( Table 1). ...
There is a growing need for marine biodiversity baseline and monitoring data to assess ocean ecosystem health, especially in the deep sea, where data are notoriously sparse. Baited cameras are a biological observing method especially useful in the deep ocean to estimate relative abundances of scavenging fishes and invertebrates. The National Geographic Society Exploration Technology Lab developed an autonomous benthic lander platform with a baited camera system to conduct stationary video surveys of deep-sea megafauna. The first-generation landers were capable of sampling to full ocean depth, however, the form factor, power requirements, and cost of the system limited deployment opportunities. Therefore, a miniaturized version (76 cm × 76 cm × 36 cm, 18 kg in air) was developed to provide a cost-effective method to observe ocean life to 6000 m depth. Here, we detail this next-generation deep-sea camera system, including the structural design, scientific payload, and the procedures for deployment. We provide an overview of NGS deep-sea camera system deployments over the past decade with a focus on the performance improvements of the next-generation system, which began field operations in 2017 and have performed 264 deployments. We present example imagery and discuss the strengths and limitations of the instrument in the context of existing complementary survey methods, and for use in down-stream data products. The key operational advantages of this new instrument are spatial flexibility and cost-efficiency. The instrument can be hand-deployed by a single operator from a small craft concurrent with other shipboard operations. The main limitation of the system is battery power, which allows for 6 h of continuous recording, and takes up to 8 h to recharge between deployments. Like many baited-camera methods, this instrument is specialized to measure the relative abundance of mobile megafauna that are attracted to bait, which results in a stochastic snapshot of the species at the deployment location and time. The small size and ease of deployment of this next-generation camera system allows for increased sample replication on expeditions, and presents a path forward to advance cost-effective biological observing and sustained monitoring in the deep ocean.
... Motu Motiro Hiva Marine Park (the marine park surrounding Salas y Gómez island) is one of the most remote and pristine protected areas of the South Pacific [12]. Often considered the easternmost extent of the Polynesian triangle (e.g., [13]), Salas y Gómez occurs within the Chilean province of Easter Island and is grouped with the surrounding small islands to form the East Island Ecoregion (EIE) [14]. ...
Background: Salas y Gómez is a small, volcanic island largely untouched by humans due to its diminutive size and remoteness. Since the waters surrounding Salas y Gómez were established as Motu Motiro Hiva Marine Park in 2010, marine investigations have been the primary research focus. Secondarily, nesting seabird communities have been censused since 2011.
Methods and findings: In 2016, terrestrial arthropods were sampled on the island. Two observers sampled two locations for 30 min per site. Fifteen morphospecies were identified including at least one likely undescribed species.
Conclusions: Our work represents the most comprehensive terrestrial arthropod inventory of Salas y Gómez island to date. We are hopeful the recommendations provided will spur additional research to both characterize the island's arthropod community, as well as identify species of management concern.
... Seamounts near Rapa Nui could have played a major role in species persistence through time, especially during the sea level fluctuations of the Pleistocene that resulted in changes of up to 150 m below present levels (Miller et al., 2005). This hypothesis is increasingly called to attention as recent surveys have shown that many Rapa Nui endemic species can be found from shallow waters to the mesophotic zone (at least 160 m) in Rapa Nui waters and in nearby seamounts (Easton et al., 2017). The palaeo-environmental perturbations of the Pleistocene might be expected to have left a footprint on the community assembly and the associated demographic histories of these populations (Bard et al., 1996;Delrieu-Trottin et al., 2017;Hewitt, 2004;Ludt & Rocha, 2015;Woodroffe et al., 2010). ...
Elucidating demographic history during the settlement of ecological communities is crucial for properly inferring the mechanisms that shape patterns of species diversity and their persistence through time. Here, we used genomic data and coalescent‐based approaches to elucidate for the first time the demographic dynamics associated with the settlement by endemic reef fish fauna of one of the most remote peripheral islands of the Pacific Ocean, Rapa Nui (Easter Island). We compared the demographic history of nine endemic species in order to explore their demographic responses to Pleistocene climatic fluctuations. We found that Rapa Nui endemic species share a common demographic history as signatures of population expansions were retrieved for almost all of the species studied here, and synchronous demographic expansions initiated during the last glacial period were recovered for more than half of the studied species. These results suggest that eustatic fluctuations associated with Milankovitch cycles have played a central role in species demographic histories and in the final stage of the community assembly of many Rapa Nui reef fishes. Specifically, sea level low stands resulted in the maximum reef habitat extension for Rapa Nui endemic species; we discuss the potential role of seamounts in allowing endemic species to cope with Pleistocene climatic fluctuations, and we highlight the importance of local historical processes over regional ones. Overall, our results shed light on the mechanisms by which endemism arises and is maintained in peripheral reef fish fauna.
... ered and described following survey campaigns and research cruises (e.g.Bett, 2012;Huvenne, 2011;Neat et al., 2019), and understanding of speciation and phylogeography in the deep sea is increasing globally(Buhl-Mortensen et al., 2017;Easton et al., 2017). Advances in data collection technologies (e.g.Jones, 2009;Wynn et al., 2014) and development of predictive modelling approaches (e.g.Davies, Wisshak, Orr, & Roberts, 2008;Rengstorf, Yesson, Brown, & Grehan, 2013;Ross & Howell, 2013) have proven to be beneficial tools for improving knowledge of deep-sea biodiversity, habitat presence, and distribution, and bringing with them progress in conservation action (as reflected in the evolution of the implementation of MPAs and fisheries management measures). ...
Despite a relatively long history of scientific interest fuelled by exploratory research cruises, the UK deep sea has only recently emerged as the subject of targeted and proactive conservation. Enabling legislation over the past 10 years has resulted in the designation of marine protected areas and the implementation of fisheries management areas as spatial conservation tools. This paper reflects on progress and lessons learned, recommending actions for the future.
Increased investment has been made to improve the evidence base for deep‐sea conservation, including collaborative research surveys and use of emerging technologies. New open data portals and developments in marine habitat classification systems have been two notable steps to furthering understanding of deep‐sea biodiversity and ecosystem functioning in support of conservation action.
There are still extensive gaps in fundamental knowledge of deep‐sea ecosystems and of cause and effect. Costs of new technologies and a limited ability to share data in a timely and efficient manner across sectors are barriers to furthering understanding. In addition, whilst the concepts of natural capital and ecosystem services are considered a useful tool to support the achievement of conservation goals, practical application is challenging.
Continued collaborative research efforts and engagement with industry to share knowledge and resources could offer cost‐effective solutions to some of these barriers. Further elaboration of the concepts of natural capital and ecosystem services will aid understanding of the costs and benefits associated with human–environment interactions and support informed decision‐making in conserving the deep sea.
Whilst multiple challenges arise for deep‐sea conservation, it is critical to continue ongoing conservation efforts, including exploration and collaboration, and to adopt new conservation strategies that are implemented in a systematic and holistic way and to ensure that these are adaptive to growing economic interest in this marine area.
... , b;Baldwin and Weigt 2012;Sparks and Gruber 2012;Walsh and Tanaka 2012;Carvalho- Filho and Ferreira 2013;Pyle and Earle 2013; Robertson 2014, 2015;Fukui and Motomura 2014; Copus et al. 2015a, b;Stiller et al. 2015;Anderson et al. 2016; Baldwin et al. 2016a, b;Carvalho-Filho et al. 2016;Pyle and Kosaki 2016;Sinniger et al. 2016;Tea et al. 2016;Tornabene et al. 2016b;Anderson and Johnson 2017;Conway et al. 2017;Easton et al. 2017Easton et al. , 2018Easton et al. , 2019Hastings and Conway 2017;Motomura et al. 2017;Prokofiev 2017;Rocha et al. 2017;Tornabene and Baldwin 2017;Walsh et al. 2017;Winterbottom 2017; Montgomery et al. 2019), algae (Norris and Olsen 1991;Ballantine and Norris 1994; Aponte 1996, 2002; Ruiz 2010, 2011;Athanasiadis et al. 2013;Tsuda et al. 2015;Spalding et al. 2016Spalding et al. , 2019a, anthozoans(Vermeij et al. 2003;Tu et al. 2012; Guzman 2013, 2016;Randall 2015;Kise and Reimer 2016;Samimi-Namin et al. 2016;Benayahu et al. 2017Benayahu et al. , 2019Rowley et al. 2019), other invertebrate groups ...
Although the existence of zooxanthellate corals in mesophotic coral ecosystems (MCEs; light-dependent coral ecosystems from 30 to 150 m in depth) has been known since the nineteenth century and focused scientific exploration of MCEs began over 50 years ago, more than 70% of all research on MCEs has been published only within the past seven years. MCEs represent approximately 80% of potential coral reef habitat worldwide, yet very little is known about them in comparison to shallow reefs. Many MCE species new to science have been discovered in the past decade, and many more await discovery. The term MCEs has been widely adopted by the scientific community since its 2008 inception; however, there is considerable inconsistency in how it is subdivided into “upper” and “lower” (and sometimes “middle”) zones. Moreover, doing so may lead to artificial boundaries when habitats and ecological communities at different depth zones may blend together. Growing evidence suggests that MCEs harbor proportionally more geographically endemic species than their shallow-water counterparts, and initial indications are that major biogeographic patterns described for shallow reef organisms may not apply to MCEs. Although MCEs may serve as refugia for some shallow species, they are increasingly recognized as unique ecosystems, important in their own right. Future research on MCEs should aim to address gaps in our understanding of the basic physical and biological characteristics of MCEs including geography, taxonomic composition, depth distribution, ecology, physiology, and connectivity. Improving knowledge of MCEs would benefit from combining different technologies to leverage the strengths of each.
... Given the proclivity for species of this genus to inhabit relatively poorly explored MCEs, as well as the stark genetic differences between P. basabei and its closest known relative, it would not be unusual for other species of this genus to be discovered elsewhere throughout the tropical Indo-Pacific region. Indeed, video captured using a remotely operated vehicle at Rapa Nui (Easter Islands) reveals what appears to be another as-yet un-named species of banded Prognathodes inhabiting MCEs (Easton et al. 2017). ...
A new species of the butterflyfish genus Prognathodes (Chaetodontidae) is described from two specimens collected at a depth of 116 m off Ngemelis Island, Palau. Prognathodesgeminussp. n. is similar to P.basabei Pyle & Kosaki, 2016 from the Hawaiian archipelago, and P.guezei (Maugé & Bauchot, 1976) from the western Indian Ocean, but differs from these species in the number of soft dorsal-fin rays, size of head, body width, and body depth. There are also subtle differences in life color, and substantial differences in the mtDNA cytochrome oxidase I sequence (d ≈ 0.08). Although genetic comparisons with P.guezei are unavailable, it is expected that the genetic divergence between P.guezei and P.geminus will be even greater than that between P.geminus and P.basabei. It is named for the strikingly similar color pattern it shares with P.basabei.
... Due to a combination of the island's remote location, limited habitat diversity, sub-tropical water temperature and relatively young geological age (Randall & Cea, 2010), the fish diversity at Rapa Nui is highly impoverished compared with other Pacific islands, with only 178 fish species currently recorded for the nearshore and epipelagic zones (Easton et al., 2017;Hernández et al., 2015;Randall & Cea, 2010 (Table 1). Prior to the sighting of this species at the Kermadec Islands (29 16 0 S, New Zealand) made in 2014 (Duffy & Ahyong, 2015;Duffy et al., 2017) the southern-most Pacific record for this species was 27 25 0 S off the east Australian coast (Johnson, 2010). ...
On 20 December, 2017, a mature Triaenodon obesus was observed at Hanga Roa Bay, Rapa Nui (Easter Island) at c.18 m depth. This observation increases both the range of T. obesus in the Pacific Ocean and the number of elasmobranch species at Rapa Nui. In combination with other recent sightings further extending the southern range of this species during the Austral summer, sea surface temperature is suggested as key to southern dispersal.
... At least two other undescribed species of this genus have been reported; one from the Coral Sea (Gerald R. Allen pers. comm.) and one from Rapa Nui (Easter Island) (Easton et al. 2017). ...
The new species Tosanoidesannepatricesp. n. is described from four specimens collected at depths of 115–148 m near Palau and Pohnpei in Micronesia. It differs from the other three species of this genus in life color and in certain morphological characters, such as body depth, snout length, anterior three dorsal-fin spine lengths, caudal-fin length, and other characters. There are also genetic differences from the other four species of Tosanoides (d ≈ 0.04–0.12 in mtDNA cytochrome oxidase I). This species is presently known only from Palau and Pohnpei within Micronesia, but it likely occurs elsewhere throughout the tropical western Pacific.
... CIMAR Islas Oceánicas 5, 6, 21, 22) and from recent field-based studies (e.g. Easton et al. 2017, 2018, Friedlander et al. 2016, Hernández et al. 2015, Wieters et al. 2014) have substantially increased the information available for this remote oceanic environment. The efforts made in the present survey provided new information on the identification of cephalopods occurring in these waters, while also highlight the necessity of continuing to explore these habitats in order to fill in knowledge gaps on reproductive ecology and dispersive stages (larval, postlarval and juvenile) of most pelagic and benthic species. ...
New records of early life stages of cephalopods are presented based on planktonic collections carried out around Easter Island (Rapa Nui; 27°70S, 109°210W) and at the nearby Apolo Seamount (located at ∼7 nautical miles southwest from Easter Island) during March and September 2015 and March 2016. A total of 13 individuals were collected, comprising four families (Octopodidae, Ommastrephidae, Chtenopterygidae, and Enoploteuthidae) and five potential genera/types (Octopus sp., Chtenopteryx sp., rhynchoteuthion paralarvae, and two undetermined Enoploteuthid paralarvae). Cephalopod mantle lengths (ML) ranged from 0.8 to 4.5 mm, with 65% of them (mainly Octopodidae) corresponding to newly hatched paralarvae of ∼1 mm ML, and 35% to rhynchoteuthion and early stages of oceanic squids of around 1.5–4.5 mm ML. These results provide the first records on composition and presence of early stages of cephalopods around a remote Chilean Pacific Island, while also providing a morphological and molecular basis to validate the identity of Octopus rapanui (but not Callistoctopus, as currently recorded), Ommastrephes bartramii and Chtenopteryx sp. around Rapa Nui waters. Despite adult Octopodidae and Ommastrephidae having been previously recorded at these latitudes, the current findings provide evidence to suggest that the northwest side of Easter Island, and one of the nearby seamounts, may provide a suitable spawning ground for
benthic and pelagic species of cephalopods inhabiting these areas. For Chtenopterygidae and Enoploteuthidae, this is the first record for the Rapa Nui ecoregion.
... Given the largely unexplored nature of many MCEs, a high rate of discovery of new fish species has been reported across a variety of locations (e.g., Pyle et al. 2008Pyle et al. , 2016bRobertson 2014, 2015;Copus et al. 2015a,b;Baldwin et al. 2016;Pyle and Kosaki 2016;Tornabene et al. 2016;Easton et al. 2016), and there is an estimated potential for thousands of species to yet be discovered from these deep coral reef habitats (Pyle et al. 2016a). Early studies in Jamaica and Belize reported 33% of fishes between 60 and 150 m represented undescribed species (Colin 1974). ...
Coral reefs
are among the most biodiverse and productive ecosystems on the planet. However, our understanding of these ecosystems and their inhabitants has primarily been gleaned from shallow-water studies (<40 m), while light-dependent corals and the ecosystems they support extend much deeper (e.g., 150 m in some locations). In recent decades, coral reef ecosystems have substantially declined globally due to direct and indirect anthropogenic activities that differentially impact shallow-water habitats. This decline has led to the suggestion that surface-oriented stressors and disturbances may be mediated by depth. The role of deeper coral reef ecosystems, called mesophotic coral ecosystems (MCEs), as refugia for shallow-water species has fueled new investigations into this realm facilitated in part by advances in diving technology and remote observation platforms. The increasing access to these poorly studied ecosystems is revealing new insights into the biodiversity of MCEs as well as that of shallow coral reefs. The upper mesophotic community is largely an extension of the shallow-water coral reef community, much of the flora and fauna are shared across these depths. However, there is a transition with increasing depth to a lower mesophotic community dominated by flora and fauna that are largely endemic to this zone. Investigations are also expanding depth and geographic ranges for many species, and new species are being discovered regularly in MCEs. However, caution must be taken when generalizing due to the geographically and numerically limited nature of these studies.
... These findings imply that numerous species are restricted to the lower mesophotic depth zone, presumably due to its unique environmental conditions. Given the largely unexplored nature of many MCEs, a high rate of discovery of new fish species has been reported across a variety of locations (e.g., Pyle et al. 2008Pyle et al. , 2016bRobertson 2014, 2015;Copus et al. 2015a,b;Baldwin et al. 2016;Pyle and Kosaki 2016;Tornabene et al. 2016;Easton et al. 2016), and there is an estimated potential for thousands of species to yet be discovered from these deep coral reef habitats (Pyle et al. 2016a). Early studies in Jamaica and Belize reported 33% of fishes between 60 and 150 m represented undescribed species (Colin 1974). ...
Coral reefs
are among the most biodiverse and productive ecosystems on the planet. However, our understanding of these ecosystems and their inhabitants has primarily been gleaned from shallow-water studies (<40 m), while light-dependent corals and the ecosystems they support extend much deeper (e.g., 150 m in some locations). In recent decades, coral reef ecosystems have substantially declined globally due to direct and indirect anthropogenic activities that differentially impact shallow-water habitats. This decline has led to the suggestion that surface-oriented stressors and disturbances may be mediated by depth. The role of deeper coral reef ecosystems, called mesophotic coral ecosystems (MCEs), as refugia for shallow-water species has fueled new investigations into this realm facilitated in part by advances in diving technology and remote observation platforms. The increasing access to these poorly studied ecosystems is revealing new insights into the biodiversity of MCEs as well as that of shallow coral reefs. The upper mesophotic community is largely an extension of the shallow-water coral reef community, much of the flora and fauna are shared across these depths. However, there is a transition with increasing depth to a lower mesophotic community dominated by flora and fauna that are largely endemic to this zone. Investigations are also expanding depth and geographic ranges for many species, and new species are being discovered regularly in MCEs. However, caution must be taken when generalizing due to the geographically and numerically limited nature of these studies.
Mesophotic and deeper habitats (∼40 to 350 m in depth) around Rapa Nui (Easter Island) were investigated using a remotely operated vehicle. We observed extensive fields of filamentous cyanobacteria-like mats covering sandy substrates and mostly dead mesophotic Leptoseris spp. reefs. These mats covered up to 100% of the seafloor off Hanga Roa, the main village on the island, located on its western side. The highest mortality of corals was observed at depths between 70 and 95 m in this area. Healthy Leptoseris reefs were documented off the northern and southeastern sides of the island, which are also the least populated. A preliminary morphologic analysis of samples of the mats indicated that the assemblage is composed of at least four filamentous taxa, including two cyanobacteria (cf. Lyngbya sp. and Pseudoanabaena sp.), a brown alga ( Ectocarpus sp.), and a green alga ( Cladophora sp.). An ongoing eutrophication process is suggested as a potential driver of the proliferation of these filamentous mats off Hanga Roa village.
The Salas y Gómez and Nazca ridges are underwater mountain chains that stretch across 2,900 km in the southeastern Pacific and are recognized for their high biodiversity value and unique ecological characteristics. Explorations of deep-water ecosystems have been limited in this region, and elsewhere globally. To characterize community composition of mesophotic and deep-sea demersal fauna at seamounts in the region, we conducted expeditions to Rapa Nui (RN) and Salas y Gómez (SyG) islands in 2011 and Desventuradas Islands in 2013. Remote autonomous baited-cameras were used to conduct stationary video surveys between 150–1,850 m at RN/SyG (N = 20) and 75–2,363 m at Desventuradas (N = 27). Individual organisms were identified to the lowest possible taxonomic level and relative abundance was quantified with the maximum number of individuals per frame. Deployments were attributed with associated environmental variables (temperature, salinity, dissolved oxygen, nitrate, silicate, phosphate, chlorophyll-a, seamount age, and bathymetric position index [BPI]). We identified 55 unique invertebrate taxa and 66 unique fish taxa. Faunal community structure was highly dissimilar between and within subregions both for invertebrate (p < 0.001) and fish taxa (p = 0.022). For fishes, dogfish sharks (Squalidae) accounted for the greatest dissimilarity between subregions (18.27%), with mean abundances of 2.26 ± 2.49 at Desventuradas, an order of magnitude greater than at RN/SyG (0.21 ± 0.54). Depth, seamount age, broad-scale BPI, and nitrate explained most of the variation in both invertebrate (R ² = 0.475) and fish (R ² = 0.419) assemblages. Slightly more than half the deployments at Desventuradas (N = 14) recorded vulnerable marine ecosystem taxa such as corals and sponges. Our study supports mounting evidence that the Salas y Gómez and Nazca ridges are areas of high biodiversity and high conservation value. While Chile and Peru have recently established or proposed marine protected areas in this region, the majority of these ridges lie outside of national jurisdictions and are under threat from overfishing, plastic pollution, climate change, and potential deep-sea mining. Given its intrinsic value, this region should be comprehensively protected using the best available conservation measures to ensure that the Salas y Gómez and Nazca ridges remain a globally unique biodiversity hotspot.
Munida diritas sp. nov. is described for the seamounts near Desventuradas Islands, in the intersection of the Salas & Gómez and Nazca Ridges, Chile. Specimens of the new species were collected in the summit (∼200 m depth) of one seamount and observed by ROV at two nearby ones. This species is characterized by the presence of distinct carinae on the thoracic sternites 6 and 7. Furthermore, it is not related with any species from the continental shelf nor the slope of America, while it is closely related to species of Munida from French Polynesia and the West-Pacific Ocean (i.e., M. ommata, M. psylla and M. rufiantennulata). In situ observations indicate that the species lives among the tentacles of ceriantarid anemones and preys on small crustaceans. The discovery of this new species adds to the knowledge of the highly endemic benthic fauna of seamounts of the newly created Nazca-Desventuradas Marine Park, emphasizing the relevance of this area for marine conservation.
Rapa Nui only allows artisanal fishery activities, but these often go unaware. The market is centralized on Pacific chub, snoek and yellowfin tuna, all common pelagic fish. On September 2016, one un-identified specimen was caught off-shore as by-catch, and left on the main port at Hanga Piko. The objective of this study was to identify the specimen to a species level, using a morphological, meristic and molecular approach. All analyses suggest that the specimen belongs to a Poey’s scabbardfish, Evoxymetopon poeyi. Concluding that the rare Poey’s scabbardfish, has an oceanic distribution through seamounts as a mid-water migrator.
• The people of the Pacific have long relied on the ocean for sustenance, commerce and cultural identity, which resulted in a sophisticated understanding of the marine environment and its conservation.
• The global declines in ocean health require new and innovative approaches to conserving marine ecosystems. Marine Protected Areas (MPAs) have been shown to be a highly effective means of conserving biodiversity and managing fisheries, while also restoring and preserving overall ecosystem function.
• Traditional ecological knowledge held by many island peoples in the Pacific is critical to the development, design and implementation of contemporary MPAs.
• Chile's offshore islands are among the few oceanic archipelagos along the west coast of South America. These islands have cultural and ecological connections to the broader insular Pacific, yet our scientific understanding of them is extremely limited.
• Chile has created several large‐scale MPAs around their offshore archipelagos. By protecting these unique ecosystems, Chile has established itself as a global leader in marine conservation.
• Effective management and a better understanding of social–ecological interactions are currently the biggest challenges facing MPAs in the Pacific Islands.
A new species, Polymixia saronovi, is described from specimens taken from a
seamount of the Kyushu-Palau submarine ridge (northwestern Pacific Ocean). It is
characterized by a high number of soft rays in the dorsal fin (35-36), a high number
of pyloric caeca (101-104), a wedgelike distribution of ctenii on the scales, and an
absence of black spots on the dorsal and caudal fins. Information on the morphology
and distribution of all ten species of the genus Po/ymixia is presented, as well as a
key to the species.
The Desventuradas Islands (San Félix and San Ambrosio) and Juan Fernández Archipelago (Robinson Crusoe and Alejandro Selkirk) are oceanic islands of volcanic origin located in the southeastern Pacific off Chile. Based on new material collected since 1997, revision of the R/V Anton Bruun expeditions collections, and a taxonomic update, the coastal fish fauna of Juan Fernández Archipelago and Desventuradas Islands found a total of 52 species, with 41 and 43 species, respectively. The number of coastal fish species recorded herein as endemic for Juan Fernández is only five (12,2%) and three species are new records (Gymnothorax cf. obesus, Gnathophis sp., Suezichthys sp). The Desventuradas Islands have only two endemic species (4,6%) and four species are new records (Scorpaenodes englerti, Maxillicosta reticulata, Suezichthys sp., Aseraggodes bahamondei). The reduced number of endemic species for the Juan Fernández Islands as compared with previous accounts (15 species) is the result that more species were found to be endemic to both islands groups (22 species = 42,3% all coastal fishes), suggesting these two island groups should be considered a single biogeographic unit. The eastern extension of the Indo West Pacific Region to include the Nazca Ridge, Desventuradas and Juan Fernández Islands is supported herein. The zoogeographical affinities between Desventuradas and western Pacific Islands (Easter Island to Australia), includes 16 species, adding five new species to previous lists. Relationships of three genera indicate a Western Pacific origin with one or more dispersal events to the Desventuradas and Juan Fernández Islands. Another seven genera, with relatively few species and restricted distribution, may have this same pattern. Only one phylogenetic study indicates a continental origin with a westward dispersal (Odontesthes), however another three genera may have this same pattern of dispersal.
Here we report on two new reef fish species from the remote and isolated Easter Island-The striped boarfish Evistias acutirostris and the ornate butterflyfish Chaetodon ornatissimus were observed during scuba dives and underwater video around Easter Island, as well as at nearby Apolo Seamount. These observations are the first records of these species for the southeastern Pacific, which represents a major extension to their distributions and raises questions about the origins and persistence of reef fishes in remote subtropical locations.
The Easter Island Province (EIP) encompasses Easter Island (EI) and Salas y Gomez Island (SGI), which are located in the eastern boundary of the south Pacific subtropical gyre. This province is one of the most oligotrophic region in the world ocean with a high degree of endemism and distinguished by having the clearest waters in the world. Issues related to the biophysical coupling that sustains biological production in this region are still poorly understood. Satellite data compiled over a ten year period was used to characterize the spatial and temporal chlorophyll-a (Chl-a) variability around the EIP and determine the relationship between Chl-a and several physical forcing. Results shows a clear Chl-a annual cycle around the EIP, with maximum concentration during the austral winter. Chl-a spatial distribution shows a strong zonal dipole over EI that divides the island into two zones: southeast and northwest. Due to its small size and low elevation of SGI, it does not generate a significant local effect in Chl-a concentration, but a Chl-a increase is observed southeast of this island (similar to 2 km) associated to a seamount. The mean geostrophic current in the EIP flows eastward, associated with the southeastern boundary of the subtropical gyre. However, recurrent mesoscale eddies traveling northwestward and produce large surface current variability with periods of high velocities in opposite direction. In the spring, wakes of high Chl-a concentration can be observed over EI, associated with the generation and detachment of submesoscale eddies from EI, which could have important biological implications during periods of low regional biological production.
Easter Island (Rapa Nui) is well studied in terms of its archaeology; however, information regarding the history of fishing is extremely limited. Marine resources have likely been exploited from the time the first Polynesians arrived on this remote island. While large pelagics are part of the traditional Rapa Nui diet, inshore fish and invertebrates have also made their way into the diet. Official records of fisheries catches in what is now the Easter Island Province of Chile, which also includes the uninhabited island of Salas y Gomez, are very limited and were available for only some years. Using anecdotal information, historical descriptions and the limited quantitative information available, we reconstructed fisheries catches in the Exclusive Economic Zone (EEZ) of the Easter Island Province over the 1950-2010 time period. Totaling almost 6,000 ton, legal catches have been increasing rapidly since the late 1970s, but are now stagnating at around 150-200 ton yr(-1). The main species targeted were Pacific chub or 'nanue' (Kyphosus sandwicensis) and yellowfin tuna or 'kahi ave ave' (Thunnus albacares), with spiny lobster or 'ura' (Panulirus pascuensis) being the most important invertebrate species. There are indications of a substantial illegal fishery for large pelagics in the EEZ of the province, estimated at 200-2,000 ton yr(-1), which may have operated for two decades and may be the cause for the declining artisanal catch of tuna by Rapa Nui fishers. Continued pressure on these geographically remote oceanic and inshore marine species, especially those popular amongst tourists, makes accounting for fisheries catches an even greater priority.
Important, often abrupt, and irreversible shifts associated with the degradation of ecosystem functioning and services are increasingly commonplace. Thus, a trait-based view of communities may be more insightful than that based solely on species composition, especially when inferring ecological responses to environmental change. This underscores the importance and urgency of establishing benchmarks against which future community changes and functional structure can be evaluated. As a first step toward setting these baselines and their current spatial variability, we here describe geographic and among-habitat patterns in the functional structure of shallow hard bottom communities, including fish assemblages, across the northeast and west coasts of Rapa Nui. We also document temporal patterns of change in dominant benthic functional groups that have taken place over the past 15 years at selected sites on this isolated Pacific island. Generally weak vertical zonation patterns were observed, with most striking differences due to the paucity of branching pocilloporid corals in shallow waters(15 m) habitats, with contrasting recovery. These results suggest depth-dependent disturbance regimes that differ in types and frequency of events, as well as capacity to recover. Overall, our results highlight the apparent resilience of the current system and provide a first-cut benchmark as to where management subsystems might be prescribed so as to spatially match ecosystem characteristics.
A review of the primary literature on the cartilaginous fishes (sharks, skates, rays and chimaeras), together with new information suggests that 106 species occur in Chilean waters, comprising 58 sharks, 30 skates, 13 rays and five chimaeras. The presence of 93 species was confirmed, although 30 species were encountered rarely, through validated catch records and sightings made in artisanal and commercial fisheries and on specific research cruises. Overall, only 63 species appear to have a range distribution that normally includes Chilean waters. Actual reliable records of occurrence are lacking for 13 species. Chile has a cartilaginous fish fauna that is relatively impoverished compared with the global species inventory, but conservative compared with countries in South America with warm-temperate waters. The region of highest species richness occurs in the mid-Chilean latitudes of c. 30–40° S. This region represents a transition zone with a mix of species related to both the warm-temperate Peruvian province to the north and cold-temperate Magellan province to the south. This study provides clarification of species occurrence and the functional biodiversity of Chile's cartilaginous fish fauna.
The Desventuradas Islands (San Félix and San Ambrosio) and Juan Fernández Archipelago (Robinson Crusoe and Alejandro Selkirk) are oceanic islands of volcanic origin located in the southeastern Pacific off Chile. Based on new material collected since 1997, revision of the R/V Anton Bruun expeditions collections, and a taxonomic update, the coastal fish fauna of Juan Fernández Archipelago and Desventuradas Islands found a total of 52 species, with 41 and 43 species, respectively. The number of coastal fish species recorded herein as endemic for Juan Fernández is only five (12,2%) and three species are new records (Gymnothorax cf. obesus, Gnathophis sp., Suezichthys sp). The Desventuradas Islands have only two endemic species (4,6%) and four species are new records (Scorpaenodes englerti, Maxillicosta reticulata, Suezichthys sp., Aseraggodes bahamondei). The reduced number of endemic species for the Juan Fernández Islands as compared with previous accounts (15 species) is the result that more species were found to be endemic to both islands groups (22 species = 42,3% all coastal fishes), suggesting these two island groups should be considered a single biogeographic unit. The eastern extension of the Indo West Pacific Region to include the Nazca Ridge, Desventuradas and Juan Fernández Islands is supported herein. The zoogeographical affinities between Desventuradas and western Pacific Islands (Easter Island to Australia), includes 16 species, adding five new species to previous lists. Relationships of three genera indicate a Western Pacific origin with one or more dispersal events to the Desventuradas and Juan Fernández Islands. Another seven genera, with relatively few species and restricted distribution, may have this same pattern. Only one phylogenetic study indicates a continental origin with a westward dispersal (Odontesthes), however another three genera may have this same pattern of dispersal.
The eastern Pacific black ghost shark, Hydrolagus melanophasma is reported from deep waters off Chile and is described from specimens collected off Valdivia at depths of 1150 to 1720 m. This species is distinguished from all other members of the genus by its large, curved dorsal fin spine, which extends beyond the dorsal fin apex; a second dorsal fin of uniform height along the caudal peduncle; large pectoral fins extending beyond the pelvic fin insertion; and a uniform black color of the body. Catch records of this species in Chile suggest a discontinuous distribution along the continental slope of the eastern Pacific Ocean, restricted to the Middle America and Atacama trenches. These observations elevate the number of chimaeroid fishes inhabiting Chile to five species.La quimera negra del Pacífico este, Hydrolagus melanophasma es reportada desde aguas profundas frente a Chile y se describe a partir de especímenes colectados en Valdivia en profundidades ente 1150 y 1720 m. Esta especie se diferencia de los otros miembros del género por su larga y curvada espina dorsal, la cual se extiende más allá del ápice de la aleta dorsal; presenta una segunda aleta dorsal de altura uniforme a lo largo del pedúnculo caudal; grandes aletas pectorales que se proyectan sobre la inserción de las aletas pélvicas, además de su coloración negra uniforme en el cuerpo. Los registros de captura de esta especie en Chile sugieren una distribución discontinua a lo largo del talud continental del océano Pacifico este, restringido a las fosas oceánicas de Atacama y Mesoamérica. Estas observaciones aumentan a cinco el número de especies de peces Chimaeriformes que habitan aguas chilenas.
The Papahānaumokuākea Marine National Monument surrounding the Northwestern Hawaiian Islands (NWHI) is the largest marine protected area in the United States and among the largest on Earth. The geographic isolation of this region has produced a unique biodiversity that is marked by particularly high levels of endemism. Previous surveys have revealed that on average 21% of reef fish species in the NWHI are endemic to the Hawaiian Archipelago. However, these endemism estimates are based on scuba surveys in shallow waters (<30 m). In areas with high water clarity like Hawaii, coral reefs can extend to depths exceeding 150 m. We conducted 52 mixed-gas dives and recorded a total of 179 reef fish species at mesophotic coral reef depths (30–90 m) across the NWHI. About 46% of encountered reef fishes in the NWHI are endemic to Hawaii, a value that is 16%–24% higher than previous shallow-water (<30 m) surveys in the NWHI, as well as nearly two-fold higher than in any other tropical region. As noted previously for shallow reefs in the NWHI, endemism appears to increase with latitude, as relative abundances of endemic reef fishes on mesophotic reefs ranged from 16% at the southernmost end of the NWHI, to upwards of 92% at the northernmost end of the NWHI. This unprecedented rate of endemism indicates that mesophotic reefs in the NWHI are reservoirs of biodiversity, and further underscores the need for protection of this area.
1. An expedition to Salas y Gómez and Easter islands was conducted to develop a comprehensive baseline of the nearshore marine ecosystem, to survey seamounts of the recently created Motu Motiro Hiva Marine Park (MMHMP) – a no-take marine reserve of 150 000km2 – and to compare these results with Easter Island where the marine ecosystem is similar but has no marine protection.
2. Live coral cover was surprisingly high at both Easter Island (53%) and Salas y Gómez (44%), especially
considering their sub-tropical location, high wave energy environments, and geographic isolation.
3. Endemic and regionally-endemic species comprised 77% of the fish abundance at Easter Island and 73% at Salas y Gómez. Fish biomass at Salas y Gómez was relatively high (1.2 t ha-1) and included a large proportion of apex predators (43%), whereas at Easter Island it was almost three times lower (0.45 t ha-1) with large predators accounting for less than 2% of the biomass, despite good habitat quality.
4. The large cohort of small sharks and the absence of larger sharks at Salas y Gómez suggest mesopredator release consistent with recent shark fishing. The fish fauna at the seamounts between Easter Island and Salas y Gómez, outside of MMHMP, harboured 46% endemic species, including a new species of damselfish (Chromis sp. nov.) and probably a new species of Chimaera (Hydrolagus). Numerous seamounts adjacent to Salas y Gómez are currently not included in the MMHMP.
5. This expedition highlights the high biodiversity value of this remote part of the Pacific owing to the
uniqueness (endemicity) of the fauna, large apex predator biomass, and geographic isolation.
Five genera of marine fishes are recognized in the family Pinguipedidae: Pinguipes, Prolatilus, Pseudopercis, Paraperci and Kochichlhys, the first three being endemic to South America. The following South American pinguipedid species are considered valid: Pinguipes brasilianus, Pinguipes chilensis, Prolatilus jugularis, Pseudopercis numida, Pseudopercis semifasciata and Parapercis dockinski. Lecto-types are designated for Pinguipes brasilianus, Pinguipes chilensis and Prolatilus jugularis.
A new species of the fish family Labridae, Suezichthys rosenblatti, is described from specimens collected at Isla San Felix, Isla Juan Fernandez and Isla San Ambrosio, off the coast of Chile. Suezichthys rosenblatti is distinct in having a combination of 11 dorsal fin soft rays and 11 anal fin soft rays. It falls in the group of species that has 1½ scale rows above the lateral line and lack a scaly sheath at the base of the dorsal and anal fins (S. aylingi Russell, S. caudovittatus Russell, S. gracilis (Steindachner & Döderlein) and S. soelae Russell). Unlike other members of this group, S. rosenblatti has haemal arches on vertebrae 10-11 (versus haemal arch only on vertebra 10). The monotypic Nelabrichthys ornatus (Carmichael) is now included in the genus Suezichthys and a revised generic description and key to species of Suezichthys is provided. The occurrence of S. rosenblatti in the south-eastern Pacific and S. ornatus in the south-western Indian Ocean and south Atlantic Ocean represent major range extensions of the genus Suezichthys.
Easter Island (Rapa Nui, Chile) is an intra-oceanic volcanic island on the Easter hotspot, ~350 km E of the Eastern Pacifi c Rise. We match new fi eld data with previously pub-lished age and petrochemical data to recon-struct the general evolution of the Island. This consists of three main volcanoes (Poike, Rano Kau, and the larger Terevaka), which expe-rienced an overall similar and nearly coeval evolution, characterized by two periods: (1) buildup of a basaltic shield, culminating in the development of a summit caldera and the emission of more evolved highly porphyritic lavas (ca. 0.78–0.3 Ma); and (2) rifting along the shield fl anks, by means of fi ssure erup-tions (0.24–0.11 Ma). The trend of most erup-tive fi ssures, NNE-SSW to NE–SW, appears to be controlled by the ~NE-SW elongated, emerged, and submerged morphology of the island. However, while the fi ssure-forming period at Rano Kau and Poike appears to be associated with reduced magma supply to the reservoir, at Terevaka it is characterized by the arrival of new basic magma, rejuve-nating the system. The comparison to other intraoceanic volcanic islands suggests that, because of its tectonomagmatic features (low eruptive rate, scattered rift zones, and scarce lateral collapses), Easter Island represents an end-member type of hotspot volcano that is contrary to Hawaii, which represents the opposite end member.
About half of the extant shark species occur only in deep waters (defined as.200mdepth), yet few published
studies on sharks include these taxa. As fisheries worldwide enter deeper waters, the provision of biological data for
these little-known taxa is critical to management and conservation. The shortspine spurdog, Squalus cf. mitsukurii, is an
abundant shark on the insular slopes of the Hawaiian Islands. We assigned ages by counting growth bands on the enamel
caps of both dorsal fin spines. Age estimates ranged from 3 to 26 years for females and from 6 to 23 years for males. Growth
was modelled with multiple length-at-age models, fitted using maximum likelihood estimation and nonlinear least-squares
methods. For female data, the logistic model yielded the most biologically cogent parameter estimates (LN
¼126 cm (total
length, TL) and k¼0.080 year
�1). The two-parameter von Bertalanffy Growth Model yielded optimal model fit and
realistic parameter estimates for males (LN
¼72 cm (TL) and k¼0.080 year
�1). Maturity ogives suggested that females
and males mature at 64-cm TL (15 years) and 47-cm TL (8.5 years), respectively. Fecundity ranged from 3 to 10 embryos;
mating appeared to be aseasonal. We reveal a conservative life history, common among deep-water elasmobranchs, and provide further evidence of geographic variation in reproductive and growth parameters in this nominal species.
The eastern Pacific black ghost shark, Hydrolagus melanophasma is reported from deep waters off Chile and is described from specimens collected off Valdivia at depths of 1150 to 1720 m. This species is distinguished from all other members of the genus by its large, curved dorsal fin spine, which extends beyond the dorsal fin apex; a second dorsal fin of uniform height along the caudal peduncle; large pectoral fins extending beyond the pelvic fin insertion; and a uniform black color of the body. Catch records of this species in Chile suggest a discontinuous distribution along the continental slope of the eastern Pacific Ocean, restricted to the Middle America and Atacama trenches. These observations elevate the number of chimaeroid fishes inhabiting Chile to five species.
An extensive series of deep-sea synaphobranchid eels was studied, primarily from previously unreported Russian collections in the southern Indian and southwestern Pacific oceans, Together with previous records, new Russian records provide a worldwide summary of the geographic and bathymetric distributions of the 14 species comprising the genera Diastobranchus, Haptenchelys, Histiobranchus, llyophis, Simenchelys, and Synaphobranchus. A diagnostic key defines species in these genera, including two newly discovered species of Ilyophis. The multi-character key facilitates unequivocal identification of synaphobranchid specimens. Diastobranchus and Histiobranchus are re-established as genera distinct from Synaphobranchus. Diagnoses of subfamilies and genera are refined, The zoogeography of studied taxa is summarized.
Easter Island (also known as Rapa Nui and Isla Pascua) lies within the southeastern Pacific high-pressure system, a feature that along with the Indonesian Low comprises the atmospheric dipole that defines the Southern Oscillation. Sea surface temperatures (SST) in the southeastern Pacific influence this limb of the basin-wide Walker circulation by modulating the stability and magnitude of convection within the regionally descending air. El Niño-Southern Oscillation (ENSO) research has most often focused on variability in the intensity and location of the Indonesian Low convective system or on teleconnections to various parts of the Northern Hemisphere. Long climate records from Easter Island will help elucidate the influence of oceanic variability on the overall ENSO system and its South Pacific teleconnections via the Walker Circulation. In addition, the Easter Island region of the South Pacific Gyre is a source for the shallow subsurface meridional flow that eventually upwells along the equator in the central and eastern Pacific [(Fig. 1); Levitus, 1982; Ji, et al., 1995; Gu and Philander, 1997]. In the northern Pacific, subsurface meridional flow has been suggested as a cause of decade-scale climate anomalies (Gu and Philander, 1997; Zhang et al, 1998). A similar mechanism may operate in the Southern Hemisphere; however, our current lack of a long time series of oceanic climate data from the eastern South Pacific Gyre, limits our ability to study this phenomenon.
Given the global degradation of shallow-water coral reef ecosystems resulting from anthropogenic activities, mesophotic coral reef ecosystems (MCEs) are gaining attention because they are generally considered a de facto refuge for shallow-water species. Despite their inferred importance, MCEs remain one of the most understudied reef habitats, and basic information on the taxonomic composition, depth range, habitat preferences, and abundance and distribution of MCE taxa is scarce. The processes that structure these communities are virtually unknown. Here, we provide a review of what is known about MCEs community ecology and outline essential gaps in our knowledge of these deeper water coral reef ecosystems. The primary findings of this review are as follows: (1) many dominant shallow-water species are absent from MCEs; (2) compared to shallow reefs, herbivores are relatively scarce, perhaps due to limited habitat complexity at depth; (3) changes in the dominant photosynthetic taxa with depth suggest adaptation and specialization to depth; (4) evidence regarding the importance of heterotrophy for zooxanthellate corals at depth is conflicting and inconclusive; and (5) decreased light with depth, but not temperature, appears to be the primary factor limiting the depth of MCEs. The majority of research done to date has been performed in the Caribbean, where some generalization can be made about the community structure and distribution of MCEs. The larger and more diverse Indo-Pacific remains largely unexplored with no apparent generalizations from the few sites that have been comparatively well studied. For MCEs, large gaps in knowledge remain on fundamental aspects of ecology. Advanced technologies must be harnessed and logistical challenges overcome to close this knowledge gap and empower resource managers to make informed decisions on conserving shallow-water and mesophotic coral reef ecosystems.
A second species of Grammatonotus from the Hawaiian Islands, tentatively identified as G. macrophthalmus Katayama, Yamamoto & Yamakawa (Callanthiidae), is recorded from French Frigate Shoals and the Northampton Seamount based on observations from a research submersible. In the absence of collected specimens, identification was made by comparing characters visible in video images with previously published images and descriptions. The fish were observed from 340 to 440 m at or near rocky habitats with crevices. All of the observations were near current-swept areas that supported gold coral (Gerardia sp.) colonies, although the fish were never seen within the colonies. A habitat feature important for both Grammatonotus and Gerardia, such as current or planktonic food supply, may therefore influence distribution of the fish. Extensive fish surveys conducted in comparable depths at other areas of the archipelago have not encountered this species, with one poorly documented exception from trawling surveys. Two other range extensions of Grammatonotus are included herein: Grammatonotus laysanus Gilbert from the Line Islands with a specimen collected at Christmas Island at 274 m and an unidentified Grammatonotus juvenile from the Tuamotu Archipelago at 705 m. Our examination of specimens and review of previous records of Grammatonotus indicate that this genus needs taxonomic revision.
Easter Island, a World Heritage Site is still, after over 50 years since Thor Heyerdahl's work on the island, a fascinating area to explore and learn about a culture that has only remnants remaining, while documenting a marine ecology still mostly unknown.
Easter Island: Scientific Exploration into the World's Environmental Problems in Microcosm presents the research results from three years of interdisciplinary expeditions to Easter Island. The primary objectives were to investigate the effects of human population growth on the ecology of the island and to discover whether any dramatic climatic changes such as a prolonged El Niño could have disrupted the island's fragile ecosystem. The interdisciplinary scientific team were mainly researching the paleontology, archaeology, climatology, and geophysics of the island. This book now brings together the results of the three expeditions, identifies new areas of research, and hopefully will continue to inspire aspiring scientists to revisit this amazing island to explore and demystify this timeless enigma of human history.
The deep ocean is a dark and unforgiving place. Buried under thousands of meters of water, the deepest part, the hadal zone, experiences extraordinary pressure. This deep seafloor habitat remains largely inaccessible to many current imaging tools. An inexpensive, reliable device is needed to explore these deep places and capture imagery of marine life in situ. The Deep Ocean Dropcam, developed by the National Geographic Society, is a low-cost research tool that can probe these depths and return valuable imagery to the surface. It combines a high-definition camera and onboard lights inside a glass pressure housing to capture high quality imagery of the deep seafloor environment. This device, deployed over 200 times in the past five years, has proven to be a robust platform for exploring the deep ocean.
The red sandperch Parapercis rufa Randall, 2001 is redescribed on the basis of three specimens newly collected from Taiwan that represent the second record of the species and first record from Taiwan. The species is now redefined as a species of Parapercis with a large black spot with whitish rim above the pectoral-fin base, upper lobe of caudal fin with a prolongation extending about 1.0-1.5 times orbital diameter posterior to rear fin margin, and a combination of coloration and morphometric and meristic data.
Easter Island sits in geographic isolation in the southern Pacific Ocean at latitude 27° 8’ S and longitude 109°20’ W, nearly 4500 km west of Chile (Fig. 1). It is a small island near the western end of a chain of volcanoes that are related to hot-spot activity dating beyond 3.5 million years before present. The small island of Sala y Gomez to the east and a series of submerged platforms are an extension of a volcanic lineament along the edge of the Nazca Plate (Kruse, et al., 1997; Newman and Foster, 1983.
Exclusively available online, http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp
The submarine seascape is one of widely scattered corals affixed to the rugged volcanic substrate. The substrate shows varying degrees of colonization by low-growing marine algae, which were affected unevenly in different areas of the island by grazing herds of sea urchins and schools of herbivorous fishes. The depauperate benthic community employs a variety of adaptive strategies for survival in an environment stressed by waves, currents and absence of mineral nutrients. Most of the corals and other bottom invertebrates are typical of Indo-Pacific reefs, but reefs are not formed. This report includes the first listings of Foraminifera and Porifera to be identified from Easter Island, as well as 16 new records of Anthozoa of which 5 are stony corals. There were 7 new family records among the Polychaeta, 68 new records of Crustacea, 37 new records of Mollusca, 16 new records of Echinodermata, and 19 new records and 15 new species of fishes. -from Authors
A review of the literature of the pinguipedid fi sh genus Parapercis is followed by the description of six new species of the genus from the western Pacifi c: P. albipinnis, one specimen from 100 m off New Caledonia, most similar to P. somaliensis Schultz, differing in having only small nodular instead of sharp serrae on the preopercle, lacking elongate upper caudal rays, and in colour; P. compressa, one specimen trawled in 40–60 m off Sumbawa, Indonesia, fi rst identifi ed as P. somaliensis from which it differs in having a more compressed body and ctenoid scales ventrally on the abdomen, prepelvic area, and cheek; P. diagonalis, four specimens (including three juveniles as nontypes) from Bali and Solor, Indonesia in 0.5–11.0 m, similar to P. maculata, differing in a higher gill-raker count, shorter pectoral fi ns, and in colour; P. fl avolineata from 34 m off Sulawesi, Indonesia, most similar to P. schauinslandii (Steindachner), differing in fewer lateral-line scales, stouter vomerine teeth, and in colour; P. shaoi from about 80–400 m off Taiwan and southern Japan, previously identifi ed as P. somaliensis, differing in lacking distinct serrae on the preopercular margin, having a larger eye, a broader interorbital space, and in colour; P. vittafrons, four specimens from New Britain in 19–22 m, closely related to P. pulchella, differing in having larger canine teeth on the side of the jaws, shorter pectoral fi ns, and in colour. Parapercis maculata (Bloch & Schneider) from the western Indian Ocean (type locality Tranquebar, India), is recognized as a valid species and distinguished from P. pulchella (Temminck & Schlegel) from Japan, Taiwan and Hong Kong. A neotype of P. maculata from Tuticorin in southeast India is described.
The subgenus Goniistius comprises eight species of marine nearshore fishes which are antitropically distributed. The molecular phylogeny of these and other cheilodactylids was reconstructed from cytochrome oxidase I and cytochrome b mitochondrial DNA sequences. The placement within Goniistius of the morphologically divergent species Cheilodactylus (G.) nigripes was not supported. The remaining seven species are sufficiently divergent from other cheilodactylids to be designated as a separate genus. The antitropical distribution of Goniistius is the result of three transequatorial divergences, which occurred during two periods. Based on molecular clock calibrations, these periods are suggested to be the mid Miocene, and late Miocene to early Pliocene. It is not known in which direction or by which mechanism these transequatorial divergences occurred, although biogeographic hypotheses of Mesozoic or Pleistocene separations can be discounted. The degree of genetic divergence between North and South Pacific populations of C. (G.) vittatus Garrett indicates that they have undergone cryptic speciation.
Four species of Squalus dogsharks, S. megalops, S. cf. mitsukurii, Squalus sp. B and Squalus sp. F inhabit shelf and upper-slope depths off New South Wales and adjacent Australian states. During fishery surveys between 1976 and 2001, distributional, size composition and reproductive data were collected for these species. Adult size classes dominated catches and, for S. megalops, heavily biased sex ratios were observed. Although no female data were available for the rarely caught Squalus sp. B, reproduction in the other three species was found to be continuous with no evidence of seasonally. Fecundity was 1-3 embryos for S. megalops, 1-5 for Squalus sp. F and 4-10 for S. cf. mitsukurii. All species are commercially exploited, contributing to the mixed species demersal trawl fishery off New South Wales. Stocks of some species are greatly depleted on the main trawling grounds, but the overall distributions of all species include large areas of lightly exploited habitat.
Fishes are now available from 22 of the numerous seamounts rising from the crests of the Nazca and Sala y Gomez Ridges which extend from Easter Island to near South America. A total of 173 species of fishes, in 66 families, exclusive of pelagic species, are now known from these seamounts, largely as the result of recent (1979 to 1987) Soviet expeditions in the area. Of these, 136 species in 58 families were found at depths of 160-580 m. The other 37 species are deeper-dwelling species found on the seamount slopes at depths of more than 600 m. There is a high degree of endemism, 42.8%, mostly related to species of Indo-West Pacific origin; 29.5% are Atlantic Indo-Pacific species; 14.4% are southern subtropical species; and 5.2% are species of uncertain assignment. Only 12 species occur on the ridges and along the coasts of South America. The vast majority are of Indo-West Pacific origin so it appears necessary to shift the boundary of the Indo-West Pacific by extending its southeastern margin from 106°W east to 80°. The high degree of endemism indiates that the area should be considered a separate zoogeographic province divided into two subareas, the Sala y Gomez Ridge and the Nazca Ridge.
The isolated Easter Island (Rapa Nui) is an outstanding example of land degradation caused by land use in a sensitive ecosystem. The focus of the investigation was placed on Poike peninsula, the most eastern part of Rapa Nui. While Poike peninsula was once supplied with fertile soils, in large areas desertification takes place today. Detailed analysis of soil profiles allowed the reconstruction of the history and of causes and effects of soil erosion and gullying in the context of land use history and cultural evolution. The results of the stratigraphic analysis prove that from the beginning of human settlement around AD 300/600 until AD 1280 the agriculture on Poike peninsula was characterised by sustainable land use and a traditional type of agro-forestry. Soil erosion was not significant. At around AD 1280 the woodland on Poike, dominated by the endemic palm Jubaea sp., was cleared by slashing and burning. Intensive farming on the upper slopes of the volcanic peninsula resulted in sheet erosion lasting until the 20th century. Settlements and ceremonial places which were built around AD 1300 on downslope areas were buried soon by sediments. Agriculture ceased around AD 1400 on downslope areas as the fertile soils were completely eroded. From AD 1400 until the late 19th century sheet erosion and the accumulation of fine-layered sediments migrated upslope. On average 8.6 Mg of soil per hectare and per year were reworked by erosion (eroded and accumulated within the catchment). Gullying began on Rapa Nui with the sudden increase in the number of sheep during the early 20th century. Gullies are still developing on the island and their ongoing enlargement created extended badlands on Poike which pose a significant problem for ecological and archaeological conservation strategies. Gullying rates exceed 190 Mg ha À 1 y À 1 . D 2005 Elsevier B.V. All rights reserved.
A new species of the genus Grammatonotus from the western part of the Pacific Ocean (the region of the Hawaiian Islands) is described. From all previously known species
of this genus, G. ambiortus sp. nova differs in multiserial teeth and the absence of canine teeth on praemaxillaria. The structure of its caudal skeleton
is also different from most species (except G. macrophthalmus from the Kyusyu-Palau Ridge); moreover it is differentiated by a large eye.
The anterior half of the mitochondrial DNA control region (mtCR) sequence (ca. 400 base pairs) was compared between two color morphotypes (A, B) of Parapercis sexfasciata from Tosa Bay, southern Japan, using 16 and 21 specimens, respectively. Intramorphotypic mtCR divergences were only 0.0–0.5% and 1.0–2.5% for morphotypes A and B, respectively. In contrast, intermorphotypic mtCR divergence was much greater, 12.7–14.0%. Furthermore, phylogenetic analysis using a neighbor-joining algorithm, with P. multifasciata as an outgroup, showed that each morphotype was reciprocally monophyletic. These results and the distinct coloration and overlapping distribution indicate that the two color morphotypes of P. sexfasciata represent two distinct species. Mismatch distribution analysis suggested that both morphotypes had undergone population expansion; however, estimates of initial population sizes and mutational timescales suggested that morphotype B comprises historically larger and older populations than morphotype A.
Study of the fauna of the submarine ridges in the south-eastern Pacific began in the 1950s, but the most detailed investigations were made in 1973–1987 during cruises of several Russian research vessels, notably the “Ikhtiandr”, “Professor Mesyatzev” and “Professor Shtokman”. At 22 seamounts of the Sala y Gòmez and Nazca ridges, 177 genera and 192 species of benthopelagic and benthic invertebrates and 128 genera and 171 species of fishes were identified. Seven genera and 150 species were described for the first time: four and 74 among invertebrates, three and 76 among fishes.
A new species of spurdog, Squalus formosus n. sp., from the lower continental shelf and upper continental slope off the coast of Taiwan and southern Japan, is described. It belongs to the 'highfin megalops group', the members of which share a short snout, high dorsal fins, robust dorsal spines, tricuspid denticles and a white posterior caudal margin. Squalus formosus is most similar to Squalus albifrons, a recently described species from eastern Australia, but differs in some morphological characters and fin colouration. Squalus formosus is sympatric with three other species of Squalus in Taiwanese waters, i.e. Squalus brevirostris, Squalus japonicus and Squalus mitsukurii, and can be readily distinguished from these in the following combination of characters: tall and upright first dorsal fin, with a tall and robust spine, short and bluntly pointed snout, white caudal-fin posterior margin and first dorsal fin with a white anterior margin parallel with dorsal spine. This new species was considered by some authors to be conspecific with Squalus blainville from the eastern Atlantic Ocean, but the results of this study reveal that it is probably endemic to Taiwan and southern Japan.
The marine flora of Easter Island is one of the least known in the Pacific. Yet it appears as a most attractive flora because of its geographic isolation. This study reports the results of an expedition to the island , providing new records on the marine algal flora, giving the first description of the intertidal and shallow subtidal vegetation, and allowing for a first marine phytogeographic characterization of the island. There is a total of 166 taxa from this relatively small volcanic island to which 66 new records have been added. The marine algal flora of Easter Island appears rich and diverse as compared with that of other similar sized islands in the central Pacific and is monotonously similar in different habitats around the island. It is short and turfy in stature, composed mainly of species with wide geographic distribution in the tropics with a general affinity to the western Pacific. The previously reported 24% endemism of the marine flora is reduced to 14% by the current study, owing to the increased numbers of non-endemic taxa. In its Indo-Pacific relationship, the flora is similar in derivation to those invertebrates that have been studied.
Easter Island: Scientific Exploration into the World's Environmental Problems in a Microcosm
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A review of the serratiid fish genus Grammatonotus, with description of a new species
- Katayama
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An annotated and illustrated catalogue of the snake mackerels, snoeks, escolars, gemfishes, sackfishes, domine, oilfish, cutlassfishes, scabbardfishes, hairtails and frostfishes known to date
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- N Parin
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Gempylidae and Trichiuridae). An annotated and illustrated catalogue of the snake
mackerels, snoeks, escolars, gemfishes, sackfishes, domine, oilfish, cutlassfishes,
scabbardfishes, hairtails and frostfishes known to date. FAO 15.
A review of the fishes of the subgenus Goniistius, genus Cheilodactylus: with description of a new species from Easter Island and Rapa
- J E Randall
Randall, J.E., 1983. A review of the fishes of the subgenus Goniistius, genus
Cheilodactylus: with description of a new species from Easter Island and Rapa.
Bishop Museum Press, Honolulu, Hawai'i, USA.