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![Studied areas at Rocas atoll, NE Brazil, indicating the different habitats.
The large scale map was plotted with the R software using the 'maptools' package [41] based on data provided by the GEOphysical DAta System—Next Generation (GEODAS-NG) of the NOAA (https://www.ngdc.noaa.gov/mgg/geodas/geodas.html). The illustration of the atoll was adapted from [39] but is not identical.](profile/Guilherme-Longo/publication/278160252/figure/fig9/AS:340496791687176@1458192169320/Studied-areas-at-Rocas-atoll-NE-Brazil-indicating-the-different-habitats-The-large.png)
Studied areas at Rocas atoll, NE Brazil, indicating the different habitats. The large scale map was plotted with the R software using the 'maptools' package [41] based on data provided by the GEOphysical DAta System—Next Generation (GEODAS-NG) of the NOAA (https://www.ngdc.noaa.gov/mgg/geodas/geodas.html). The illustration of the atoll was adapted from [39] but is not identical.
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The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern Atlantic. We provide the first compre...
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In this study, fishes and habitat attributes were quantified, four times over 1 year, on three reefs within four regions encompassing a c. 6 • latitudinal gradient across southwestern Australia. The variability observed was partitioned at these spatio-temporal scales in relation to reef fish variables and the influence of environmental drivers quan...
Citations
... Reef fish assemblages are known to be associated with the benthic assemblages 56,57 , with fish diversity being linked to the heterogeneity of rocky bottoms 58,59 . The abundance of roving herbivores of the families Acanthuridae and Scaridae (actually recognized as Labridae) on Elkhorn Reef in Florida increased as coral cover decreased and the macroalgal cover increased 60 . ...
The low-latitude habitats of the South American reef system have a high endemism and represent important stepping-stones due to the connectivity with Amazon and Caribbean reefs. We provide the first seabed mapping, and analyze the benthic cover and fish assemblages of these extreme reefs. Fleshy macroalgae (2—66% of cover), algal turfs (0—47%), and sponges (3—25%) are the dominant benthic groups. The main reef builders are crustose coralline algae (2—23%) and only four coral species (0 to 18%), mainly the weedy Siderastrea stellata. Cluster analysis distinguished two groups. The first group includes the shallowest reefs (~ 17 m deep) where fleshy macroalgae are abundant together with higher siltation on the reefs (~ 31% covered by sediments). The second group, by contrast, includes the deeper reefs (22.5—27 m), which have much higher algal turf cover, and the lowest sediment cover (4%). The deeper reefs also have the highest cover of corals (18%) and sponges (25%). We recorded a total of 63 fish species, with the deep reefs being the richest. Analysis indicated that the composition of the benthos was considerably more homogeneous across the study area than the composition of fish assemblages, which had a higher turnover of species among reefs. Moreover, we identified the depth of the reef as a variable structuring the benthic assemblages. The fish assemblage is influenced, in turn, by the benthos. Overall, the seabed mapping revealed the existence of a single reef system with high spatial heterogeneity. Our results provide new insights into the structure of these extreme reefs that have evolved under the influence of sediment resuspension, moderate turbidity, and are warmer than other West Atlantic reefs located at middle- and high-latitudes.
... In the oceanic islands, the great biomass is in part explained by the abundance of the black triggerfish Melichthys niger particularly in Trindade Island (Pinheiro et al. 2011) and St. Paul's Archipelago (Luiz et al. 2015). At the only atoll in South Atlantic, Rocas Atoll, reef fish biomass is dominated by large predators such as sharks (Negaprion brevirostris), snappers (Lutjanus jocu), and herbivorous fishes (Acanthurus spp.; Longo et al. 2015). Fish feeding pressure at these oceanic islands are mostly related to herbivory by Acanthuridae (Longo et al. 2015) or even by the omnivorous M. niger acting as a functional herbivore (Mendes et al. 2019) (Figure 3.9). ...
... At the only atoll in South Atlantic, Rocas Atoll, reef fish biomass is dominated by large predators such as sharks (Negaprion brevirostris), snappers (Lutjanus jocu), and herbivorous fishes (Acanthurus spp.; Longo et al. 2015). Fish feeding pressure at these oceanic islands are mostly related to herbivory by Acanthuridae (Longo et al. 2015) or even by the omnivorous M. niger acting as a functional herbivore (Mendes et al. 2019) (Figure 3.9). ...
The origin of most reef biodiversity of the southwestern Atlantic Ocean dates back to the Eocene, when the center of diversity of modern reef organisms was in the Tethys Sea, a vast extent of tropical shallow marine habitats situated between the Atlantic and Indian oceans. Following the closure of the Tethys Sea, the Atlantic reef biodiversity became increasingly isolated from the world’s centers of biodiversity (i.e. tropical Indo-Pacific). Moderate rates of origination and extinction shaped endemic lineages and a lower diversity of species compared with the Indo-Pacific. Within the Atlantic, the Brazilian Province is characterized by high endemism and by the presence of a secondary center of biodiversity, driven by a combination of isolation, distinct ecological conditions, and the overlap of tropical and subtropical species. Many evolutionary processes shape the current distribution of species along the coast and in offshore areas such as seamounts and oceanic islands. The taxonomic and functional structure of reef fishes and benthic organisms in the Brazilian Province are related to both historical events and environmental factors, and changes considerably along its latitudinal extent. Today, increased and disordered human development, associated with inadequate conservation measures, is quickly threatening millions of years of eco-evolutionary processes responsible for the origin of this unique biodiversity.
... In the oceanic islands, the great biomass is in part explained by the abundance of the black triggerfish Melichthys niger particularly in Trindade Island (Pinheiro et al. 2011) and St. Paul's Archipelago (Luiz et al. 2015). At the only atoll in South Atlantic, Rocas Atoll, reef fish biomass is dominated by large predators such as sharks (Negaprion brevirostris), snappers (Lutjanus jocu), and herbivorous fishes (Acanthurus spp.; Longo et al. 2015). Fish feeding pressure at these oceanic islands are mostly related to herbivory by Acanthuridae (Longo et al. 2015) or even by the omnivorous M. niger acting as a functional herbivore (Mendes et al. 2019) (Figure 3.9). ...
... At the only atoll in South Atlantic, Rocas Atoll, reef fish biomass is dominated by large predators such as sharks (Negaprion brevirostris), snappers (Lutjanus jocu), and herbivorous fishes (Acanthurus spp.; Longo et al. 2015). Fish feeding pressure at these oceanic islands are mostly related to herbivory by Acanthuridae (Longo et al. 2015) or even by the omnivorous M. niger acting as a functional herbivore (Mendes et al. 2019) (Figure 3.9). ...
Rocky shores are prominent features of the Brazilian SE-S coast that define the coastal contour in the region and are interspersed by sand beaches. The intertidal and subtidal zones are discussed here as a continuous along the depth gradient, where large rocky formations plunge into the sea and are bordered by a soft sediment basin. The SE-S rocky shore range overlaps climatic and oceanographic domains, with NE currents and winds, and cold fronts coming from S-SW during the dry season. The SE-S shores represent a gradual change in species composition from tropical to subtropical-temperate provinces, where some taxonomic groups peak in species richness along the Rio de Janeiro and São Paulo shores associated with less heterogeneous climatic and oceanographic domains. Fish, mollusk, ascidian, and sponge species richness decrease southward, while corals decrease in subtropical areas mostly because of their clear association with tropical waters. Although some rocky shores are within marine and coastal protected areas, the total area covered and the real enforcement applied to those protected areas are below desirable levels. These habitats are among the most impacted on the Brazilian coast because of their proximity of large cities and should be prioritized in sustainable development initiatives and coastal management planning.
... The animals they were describing were found from the intertidal zone down to 2 m depth, in waters ranging from 25°C to 28°C, which is too warm for the closely related species O. americanus (Á ngeles-González et al., 2020). (Fasca et al., 2007), to tropical islands such as Rocas Atoll, where the water temperature reaches up to 36°C in shallow habitats in the atoll lagoon (Longo et al., 2015). The species also seems to have a high tolerance to variation in salinity since it has been recorded from estuaries of small rivers on the Northeastern coast of Brazil (F.D. Lima, pers. ...
... proper and sandy deposits (up to 20m) (Kikuchi and Leão, 1997;Leão et al., 2003;Longo et al., 2015). The locality of Fernando de Noronha (FN) is a volcanic archipelago of rocky reefs, that comprises shallow to mesophotic reefs, including some rhodolith beds (Amado-Filho et al., 2012;Matheus et al., 2019). ...
The Southwestern Atlantic (SWA) harbors a relatively species poor but highly endemic coral assemblage due to historical processes, environmental and ecological drivers. Despite its low to moderate cover, corals still have a disproportionate contribution to ecosystem function and stability in this region. In the context of global change, it is imperative to know corals’ diversity and biogeographic patterns, yet a comprehensive approach is still missing for SWA corals. We integrated occurrence data from 21 sites and nine functional traits across 20 coral (scleractinian and hydrozoan) species to explore the taxonomic and functional diversity of coral assemblages in the SWA (1°N-27°S). We identified eight regions based on coral species composition, and then described their functional diversity using four metrics: functional richness (FRic), functional dispersion (FDis), functional evenness (FEve), and functional originality (FOri). Taxonomic and functional diversity peak between latitudes 13°S-20°S, decreasing with increasing distance from this diversity center, known as the Abrolhos Bank that harbors a wide continental platform. Our findings reveal a prevalent pattern of high functional redundancy across these eight regions (indicated by low functional originality), with species occupying the edges of the trait space (high functional evenness) and converging around few trait values (low functional dispersion). Such patterns resulted in low taxonomic and functional beta diversity and increased nestedness among regions caused by dispersal barriers and environmental filtering. The Southernmost region (24°-27°S) has the lowest taxonomic and functional diversity and comprises only two species that share similar traits, with these corals being: hermaphrodites, brooders and depth-tolerant, and having a wide corallite. As this region might become critical for corals in a future tropicalization scenario, tropical corals that share similar traits to those of the southernmost region can be more likely to thrive. Knowledge on taxonomic and functional diversity patterns can offer critical information to conservation by helping prioritizing areas with higher diversity and species with traits that enhance survival under climate change.
... The lack of hyperdominance of M. niger in the Caribbean is likely a result of the high regional species richness, since the herbivory function is shared among several species. Similarly, in the open pools of Rocas Atoll, M. niger appeared among the 4 most important fish species foraging over reef substrates (Longo et al. 2015), but it did not exhibit hyperdominance either, since herbivorous surgeonfishes (Acanthurus chirurgus and A. coeruleus) and parrotfishes (Sparisoma amplum and S. axillare) are abundant. In fact, M. niger is found both in Rocas Atoll and Fernando de Noronha, but never reaches hyperdominance (Krajewski & Floeter 2011, Longo et al. 2015, Morais et al. 2017. ...
... Similarly, in the open pools of Rocas Atoll, M. niger appeared among the 4 most important fish species foraging over reef substrates (Longo et al. 2015), but it did not exhibit hyperdominance either, since herbivorous surgeonfishes (Acanthurus chirurgus and A. coeruleus) and parrotfishes (Sparisoma amplum and S. axillare) are abundant. In fact, M. niger is found both in Rocas Atoll and Fernando de Noronha, but never reaches hyperdominance (Krajewski & Floeter 2011, Longo et al. 2015, Morais et al. 2017. Our study provides further evidence of the remarkable plasticity and adaptability of M. niger to different local conditions. ...
... On the other hand, A. coeruleus is the single acanthurid that browses on EAM in the Atlantic Ocean (Ferreira & Gonçalves 2006). Interestingly, in Rocas Atoll, sediment and detritus represent a large proportion of the diet of A. chirurgus, while A. coeruleus ingested mainly red corticated algae, especially Digenea simplex (Longo et al. 2015). This suggests a higher feeding plasticity of A. chirurgus that feeds on EAM and sandy habitats, while A. coeruleus feeds more predominantly on EAM and macroalgae. ...
Spatial and temporal patterns of benthic community structure play a crucial role in shaping reef habitats and have a direct impact on fish foraging dynamics, alongside density-dependence effects on the whole community. In isolated oceanic islands, the relatively low fish species richness often leads to the hyperdominance of a few species and a general reduced trophic redundancy. However, the influence of benthic habitat features and hyperdominant species on foraging selection in oceanic islands has been largely overlooked. This study aimed to investigate, using Remote Underwater Videos (RUVs), whether reef fishes consistently forage on specific habitats across five different oceanic islands in the Atlantic Ocean, especially focusing on the importance of the role of hyperdominant species. We analysed 295 RUVs, within 2m2 areas (3-15 m deep), totalling 49 hours of video. Photoquadrats were utilised to gauge benthic group coverage in the same habitats. Our results revealed five prevalent habitats and six fish trophic groups interacting with reef benthos. The intensity of feeding pressure varied across islands, depending on the diversity of habitats. Herbivores and omnivores exhibited the highest feeding pressure, with omnivores foraging on crustose coralline algae and macroalgae habitats, while herbivores primarily fed on habitats dominated by the epilithic algal matrix. Hyperdominant species forage in multiple habitats, indicating a comparatively high degree of dietary plasticity. Our findings also demonstrated that fish feeding pressure is influenced by both habitat features and fish biomass. Therefore, our study can provide valuable insights for prioritising the management of key species in isolated oceanic reefs.
... Its reefs are built primarily by encrusting coralline red algae, and the secondary framework builders are composed of vermetid gastropods, encrusting foraminifera, polychaete tubes, and corals. The three main habitats found in the inner reef area of the atoll are a shallow permanent lagoon, and closed and open pools (Longo et al., 2015). ...
... In this sense, the differences observed between closed and open pools can be mainly attributed to the dominance of non-calcified algal turf (51 %) in closed pools, while open pools are dominated by articulated calcareous algae (33 %). In addition, coral cover has been described as significantly lower in closed pools than in open pools (Longo et al., 2015). ...
... It is already known that these islands exhibit high levels of endemism in marine taxa [42][43][44], and are important breeding sites [45][46][47][48]. Despite the growing anthropic pressures [49], some of them still present coral reefs considered "pristine", for example, Rocas Atoll [50,51]. ...
The polychaete Family Cirratulidae is one of the most abundant and diverse groups of Annelida, although it remains poorly known worldwide. Dodecaceria Ørsted, 1843 is one of the least described genera of Cirratulidae. The present report is the first taxonomic study of the genus Dodecaceria for the Brazilian coast. Cirratulidae were collected at Rocas Atoll, the first Brazilian marine protected area and the only atoll in the South Atlantic Ocean. We described one new species, Dodecaceria zelinhae n. sp., and a new record of D. dibranchiata Blake & Dean, 2019, previously only known from Panama. The new species is distinguished from other Dodecaceria species by having lateral tentacles, a smooth peristomium, 3–5 pairs of branchiae, hooks from chaetiger 11 in notopodia and 9 in neuropodia. Dodecaceria dibranchiata, a Caribbean species, is here recorded for the first time in the South Atlantic Ocean.
... The three oceanic islands that occur along the NB (St. Peter and St. Paul Archipelago, Rocas Atoll and Fernando de Noronha) were not included, as their fish faunas have been treated in detail elsewhere (e.g., Batista et al., 2012;Feitoza et al., 2003;Ilarri et al., 2017;Krajewski & Floeter, 2011;Lubbock & Edwards, 1981;Longo et al., 2015;Luiz et al., 2015;Pinheiro et al., 2020;Rosa & Moura, 1997;Rosa et al., 2016;Soto, 2001;Vaske et al., 2005). ...
The richness of marine teleost fishes from the tropical northeastern Brazilian coast was compiled through an extensive search of published species records and of voucher specimens in collections. Results are presented in a systematic listthat includes 571 marine species across 98 families considered as valid records in coastal and estuarine environments.516 species (90.4%) are represented by voucher specimens in collections. Species reported in the literature with pending confirmation, or known only from vouchers, may add 72 species to the list, 18 of them without previous mention in theliterature representing new records for the study region. Brazilian endemic species are also reported, seven of which are exclusive to the northeastern coast. Additionally, 91 species belonging to 41 families are treated as erroneous or doubtful records for the region, and their geographic distribution or taxonomic status commented upon. Among the validspecies recorded, 21 are listed as threatened according to the IUCN Red List and 24 by the Brazilian official list of threatened species. At least four species introduced in the Western Atlantic are now considered invasive in northeastern Brazil. The data presented herein result from the most comprehensive survey of the coastal marine ichthyofauna of northeastern Brazil. It adds 154 species records when compared to the maximum species richness previously reported for the study region in a single publication and serves as a baseline to promote future studies in fish systematics, biogeography, ecology and conservation. Notwithstanding, the species richness of this region remains an underestimate pending additional taxonomic research and the availability of online data for regional collections
... For example, local scale species variation in deep sea were determined by oxygen availability, nutrient distribution, and interaction between organism and/or surrounding environment (Schaff and Levin, 1994;Danovaro et al., 2001). In contrast, the pattern of species in bigger scales have been addressed to biogeographic factors such as bottom current, hydrodynamic regimes, and nutrient input (Galéron et al., 2000;Longo et al., 2015). The systematic monitoring of changes in the variability of meiofauna assemblages across various habitats, therefore, is important for long-term ecological assessment. ...
This study was conducted to investigate the spatiotemporal variability in subtidal meiofaunal assemblages off the southern coast of Korea at local and regional scales. Abiotic and biotic samples were collected by site (three sites at least 10 km apart) within region (three coastal regions at least 50 km apart) over 7 years (2015-2021). The density and taxon richness of meiofaunal assemblages differed significantly among sites, but not among regions or years. The meiofaunal assemblage composition differed significantly among sites, regions, and years. A distance-based multivariate multiple regression analysis revealed that the mean sediment grain size and total nitrogen, lead, nickel, chromium, and aluminum concentrations were key environmental variables determining the variation of the meiofaunal assemblages. This study can provide basic ecological data for understanding the spatiotemporal distribution of meiofauna assemblages and aid in the development of management strategies to mitigate marine pollution on the southern coast of Korea.
