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A preliminary study of small scavenging crustaceans collected by baited traps in a coral reef of bidong Island, Malaysia
Abstract and Figures
In order to examine small invertebrate scavenging fauna of tropical coral reef waters, baited traps were deployed in a coral reef of Bidong Island, Malaysia. The samples taken by the traps constituted only a single species of isopods (Cirolana sp.) and ostracods from three families (Cypridinidae, Cylindroleberididae, and Paradoxostomatidae). Cirolanid isopods were never collected in net-samples suggesting they are hyperbenthic scavenging species. Judging from its sheer numbers in the bait-attracted community (86.1-98.6%), cirolanid isopods are one of the most important small invertebrate scavengers in coral reef waters of Bidong Island.
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... According to Kornicker (1994), Xenoleberis differs from Bathyleberis by well-developed d-and e-bristles on the first antenna. Besides these four named species, there are at least three species left in open nomenclature, one from the Chatham Rise near New Zealand (Bowden et al. 2017;Bowden and Leduc 2017), one from coral reefs in the South China Sea off Malaysia's Bidong Island (Nakajima et al. 2015), and one from the Ariake Sea at Kyushu, Japan (Tanaka and Ohtsuka 2015). Figure 1 shows the global distribution of Xenoleberis. ...
... Xenoleberis is distributed from tropical to boreal zones ( Figure 1), but most of the species are known from the temperate regions, in particular from the Northwest Pacific Ocean. The genus has only one representative from the tropics, namely, an unidentified Xenoleberis species that has been reported from a coral reef in Malaysia (Nakajima et al. 2015) (see Figure 1). Unfortunately, no further descriptions or illustrations are provided by the author; hence, we could neither identify the species nor confirm its genus affiliation. ...
Cylindroleberididae is a peculiar ostracod myodocopid family, characterized by the presence of gills. It accounts for over 200 species described from all bathymetric ranges and from all the world’s oceans. Nevertheless, its biodiversity is still underestimated, with each study brining new taxa to the list. As a result of recent sampling effort in seas around Korea and Japan, we report five cylindroleberid taxa. One of those is described as a new genus (Toyoshioleberis gen. nov.), and four belong to Xenoleberis Kornicker, 1994. Of the latter, three are described as new species, and one has already been reported from Japan, but is the first record for Korea. In fact, our study is also the first record of the family from this country. Having fresh samples provided an opportunity to obtain sequences of three gene markers (16S, 28S, and 18S rRNA), and, by combining those with the ones belonging to Cylindroleberididae available in GenBank, we reconstruct a molecular phylogeny with the aim to assess the position of the new taxa within the family and try to resolve the currently polyphyletic nature of some cylindroleberid taxa. The results of the phylogenetic analyses indicate the monophyly of Xenoleberis and its deep separation from Toyoshioleberis, along with distinct morphological features genetics to support our taxonomic decision. In addition, the phylogenetic results confirm that the general systematic of Cylindroleberididae should be reassessed, in particular the tribes of the subfamily Cyclasteropinae should be given a higher systematic ranking, as suggested previously based on morphology alone.
... Islands located off the east coast of Peninsular Malaysia have received very little research effort on avifauna. However there have been some surveys conducted on other organisms and plants on Bidong Island, for example, algae (Armugam 1981;Khor 2002), butterflies (Rosmidi et al. 2017), dipterocarp trees , bats , crustaceans (Nakajima et al. 2013), fish (Jeropakal 1998;Lorenzo et al. 2016) and reptiles (Grismer et al. 2014). ...
Bidong Island is one of the least known islands in terms of birds; very few surveys have been conducted on this island. The island is part of a small archipelago called Bidong Laut, located to the northwest of Kuala Terengganu, on the east coast of Peninsular Malaysia. A total count of 30 bird species, from 19 families and 25 genera were found on this island between 2006 and 2020. Collected data (nine days) were analysed for biodiversity indices. Alpha diversity indices showed
variations among sampling years, Simpson 1-D range 0.76–0.89; Shannon (H) range 1.74–2.48; species richness 8–16 species; dominance (D) range 0.11–0.24. Species richness estimators indicate that more species can be added with additional sampling and better coverage of the island area. The relatively low avian species richness compared to other east coast islands is discussed. Further surveys during migration season can reveal the importance of this island as a stop over site for several migratory species.
... This applies on most islands located off the east coast of Peninsular Malaysia. However, there were some surveys conducted on other organisms and plants on Pulau Bidong, for IN PULAU BIDONG, MALAYSIA example, Algae (Armugam, 1981, Khor, 2002, butterflies (Rosmidi et al., 2017), Dipterocarp trees (Pesiu et al., 2016), bats , crustaceans (Nakajima et al., 2013), fish (Jeropakal, 1998, Lorenzo et al., 2016 and reptiles (Grismer et al., 2014). ...
Avian diversity study focusing on islands in Malaysia is generally scarce compared to the unsurprisingly wealth of information on mainland birds. Similarly, Pulau Bidong is one of these islands with scarce ornithological information. It is located to the northwest of Kuala Terengganu, East Coast Peninsular Malaysia. A series of field surveys were conducted on the island between August 2014 and August 2016, using both point counts and mist netting methods to assess the bird species diversity at coastal area and within the forest canopy of the island. Unpublished data from 2006 were also added as it covers the Bidong trail area. Our results indicate that the total count is 26 species, belonging to 18 families and 23 genera. This species list is not exhaustive because the survey did not cover the main migration season from October to February, when it coincides with the monsoon season and rough weather. Further surveys will be needed to cover the nearby small islands in the archipelago.
... Corals in the islands were also reported to induce the healthy microbial environment due to their mucus content (Nakajima et al. 2009). Scavenger invertebrates of 1 mm size and above in the coral area were reported in high abundance and dominated by Isopoda (Nakajima et al. 2013). ...
Meiobenthos in Bidong Archipelago in coastal water of the South China Sea is hypothesised to have a certain trend of distribution particularly in the island ecosystem where it is usually having different type of sea bottom. Nonetheless, since it is located in a tropical area, the trend at the sub-tidal could be less obvious due to absent of clear season. Meiobenthic sampling was carried out in Karah Island, an island in Bidong Archipelago, from the intertidal, towards the sub-tidal zone covering the coral and non-coral area to see the trend in the density and composition. A transparent hand core was used to collect benthos samples. Nematoda and harpacticoid copepods dominated the intertidal and sub-tidal zone respectively. Harpacticoid copepods were higher in density in the non-coral sediment than the coral area. This could be due to the high content of silt and clay in the coral area (2.98% of silt and clay). The 2-dimension MDS analysis on the density data indicated the highest degree of scattering and an over-lapping condition for those intertidal and sub-tidal samples respectively. ANOSIM result showed that the degree of similarity was lower at the intertidal (70%) than the sub-tidal (reaching 90%) in the first sampling before both became no significant different in the second sampling. It could indicate the stable condition in the subtidal than the intertidal ecosystem. The comparatively low density of meiobenthos could indicate their response towards the environmental condition in the area which will only be confirmed by long term ecological study.
Cirolana westbyi n. sp., a novel species in the ‘Cirolana parva-group’ is described from the Turneffe Atoll, Belize using an integrated molecular and morphological approach. The 18S ribosomal RNA gene for C. westbyi n. sp. and also for Cirolana parva Hansen, 1890 are provided, in addition to new primers, developed for the Cirolanidae 18S gene.
The key morphological character for separating C. westbyi n. sp. from other Cirolana is the shape of the uropodal rami: the uropodal endopod is convex on the lateral side while the mesial side is straight. Comparison of the 18S gene shows that C. parva is 95.96% identical to C. westbyi n. sp. across 68% coverage, but due to two unique insertions (‘INS-1’ and ‘INS-2’) into the 18S gene of C westbyi n. sp., which may function as loop regions, they appear to be genetically distinct and different species. This is also supported by phylogenetic analysis, which also highlights some potential paraphyly between the three families, Cirolanidae, Aegidae and Corallanidae.
Our morphological description of a new species of cirolanid along with a phylogenetic support using 18S sequence data for species within and around the Cirolanidae, provides greater context for the ‘Cirolana parva-group’.
Pulau Bidong is known for its history as a Vietnamese refugee settlement during the Vietnam War in the 1970s. By the 1990s, this island was under the jurisdiction of the state government of Terengganu, Peninsular Malaysia. Now, Pulau Bidong is the marine research centre for the Universiti Malaysia Terengganu (UMT MaReSt). It is a low-lying ecosystem harbouring flora and fauna not yet discovered. To date, there is no documented evidence on richness, diversity, and abundance of molluscan fauna found on the island. This study aims to identify diversity, distribution, morphological characteristics, and conservation status following the International Union for Conservation for Nature (IUCN) of marine gastropods. Sampling was done in August 2017 at two selected stations using the Smith-McIntyre grab and dredge. A total of 140 individuals representing three subclasses, 14 families, and 25 species were found. The highest number of individuals collected belonged to Minolia ceraunia (Solariellidae), with 27 individuals, followed by Margistrombus marginatus (Strombidae), with 20 individuals. Ecological indices, like the Shannon index (H') and Simpson index (D), showed that species diversity was 2.67±0.20 and 0.90±0.02, respectively, indicating moderate to high diversity. In addition, Margalef (Ma) and Menhinick (Me) indices showed high variation scores of 4.61±0.44 and 2.16±0.09, indicating high species richness. Similarly, Evenness (J') and Equitability (Ep) recorded 0.65±0.09 and 0.86±0.04, respectively, showing high homogeneity and distribution pattern of species in relation to other species. All marine gastropods were categorised as 'Not Evaluated' following IUCN. This study provided baseline information for malacology communities and highlighted insufficient information, so a proper assessment of conservation status can occur. Extending the sampling period is recommended, so further surveying and monitoring of other benthic taxa, including algae, crustaceans, molluscs, and polychaetes, can provide a comprehensive study useful for scientists and members, for future follow-up and evaluation programmes.
The dominant group of carrion-eating amphipods in Norway are the Lysianassoidea; they play an important role as scavengers in Norwegian and arctic waters. A number of genera damage fish caught in nets and on long-lines; in Norway the most serious damage is done by Anonyx and Tmetonyx species. Tmetonyx cicada and the isopod Cirolana borealis have also regularly been found in Cod roe. Symbionts of living fish belong to the genera Lafystius, Normanion, Opisa and Trischizostoma. Lafystius and Normanion have low host specificity, Opisa eschrichtii is found on gadids and Halibut Hippoglossus hippoglossus and Trischizostoma raschi on the small shark Etmopterus spinax. Little is known on the biology of these species.
Predation is assumed to be a principal cause of adult fish mortality on coral reefs, and therefore a main pathway by which biomass is passed to higher trophic levels. However, the strength of predation has mostly been demonstrated on juvenile fish, and even with juveniles, when predators are excluded, substantial mortality still occurs. Mortality from causes other than predation is rarely considered, because carrion is not common on coral reefs, but the strength of this inference depends crucially on the rate of scavenging. We tested the hypothesis that removal of carrion through scavenging may be very rapid by placing undamaged fish carcasses of a range of species and sizes on reefs in Curaçao, monitoring their rate of disappearance. All carrion was consumed within 24 h and at such rapid rates that, if non-predation mortality were occurring, it would leave little evidence on the reef. Carcasses were consumed almost exclusively by fish, mainly reef-associated piscivores, indicating that scavenged biomass is tightly recycled within the reef fish community. The results of this study suggest that more attention should be paid to quantifying the role of non-predation sources of fish mortality in reef ecosystems.
The relative roles of competition and predation in demographic density de-pendence are poorly known. A tractable experimental design to determine such effects and their interactions for demersal (seafloor oriented) fishes and similar sedentary species is cross-factoring multiple densities of new recruits with the presence and absence of predators. This design allows one to distinguish between density-dependent mortality due to com-petition alone, predation alone, or an interaction between the two, especially when sup-plemental field observations are available. To date, 14 species of marine fish have been examined with some variant of this design, and for 12 species predation was demonstrated to be the sole or major cause of density dependence. However, as competition may be slow acting relative to predation, the importance of competition can be underestimated in short-term experiments. On the Great Barrier Reef, we conducted a long-term field experiment in which multiple densities of new recruits of a planktivorous damselfish were cross-factored with the presence or absence of resident piscivorous fish on patch reefs. During the first 10 months, no density-dependent mortality was detected, regardless of whether resident predators were present or absent. By the end of the experiment at 17 months, per capita mortality was strongly density dependent and highly compensatory in both predator treat-ments; all reefs ultimately supported nearly the same adult density regardless of experi-mental treatment. Examination of treatment effect sizes suggested that competition was the main source of density-dependent mortality, with predation being merely a proximate agent of death. We hypothesize that predators were ineffective in this system compared with similar studies elsewhere because prey density was low relative to ample prey refuges provided by highly complex corals. Combined with previous studies, these findings indicate that density-dependent mortality in demersal marine fishes is often caused by interplay of predation and competition, whose roles may be altered by variation in habitat complexity and larval supply. These conclusions are relevant to marine fisheries models, which typically assume that density dependence is due solely to intraspecific competition.
All coral reef organisms are susceptible to diseases, as are terrestrial organisms, but studying these diseases can be more difficult and much remains to be learned. Although health impairments of corals were first recognized only in the early 1970s, increasing numbers of infectious and non-infectious diseases, causing morbidity and mortality in numerous species of tropical marine organisms, have now been identified in diverse species of algae, plants, invertebrates, and vertebrates. Causes of diseases include biotic, as well as abiotic, factors, but identifying a primary pathogen has been reported in only a few cases, and some of those results have been questioned as additional diagnostic tools have been applied. The multitude of stressors affecting reef organisms, particularly along heavily urbanized coastlines, as well as introductions of species to distant reefs by global transport, are contributing to concerns about extinction risks and loss of biodiversity. This chapter presents an overview of diseases of reef organisms, how diseases have adversely affected coral reefs, and new developments in disease diagnoses. The application of concepts from the field of conservation medicine are aiding our understanding of diseases and their impacts on organisms of these shallow to mesophotic ecosystems.
Extensive use of baited traps in deep-sea collecting during recent years has shown fishes and amphipods to be the dominant carrion-feeders in the abyssal habitat. All amphipods regularly obtained in such deep-sea traps belong to the family Lysianassidae. In the present investigation five carrion-feeding deep-sea lysianassids from the Atlantic and the Pacific have been studied with respect to possible adaptations for their particular ecological niche in the chemosensory equipment and the alimentary system. The special arrangement of chemosensory organs on the lysianassid antennulae can be seen as a general adaptation for chemosensory food localization, better developed than in most other amphipods. There is no immediately obvious difference in this respect between related deep-sea and shelf taxa. In the mandibles modification for dealing with large carrion has led to far-reaching morphological transformations away from the traditional amphipod pattern and apparently along different lines. In all species the alimentary canal is adapted for large scale food storing but along two completely different and mutually exclusive lines. In one genus a progressive intestinal adaptation for storage is suggested by a comparison between one shelf species and two deep-sea species. It is obvious that within the Lysianassidae two or more widely diverging evolutionary lines have led to successful adaptation to deep-sea carrion feeding. /// Широкое применение приманочных ловушек при глубоководных сборах за последние годы показало, что рыбы и амфиподы - доминирующие потребители трупов в абиссальных местообитаниях. Все амфиподы, регулярно попадающие в такие глубоководные ловушки, принадлежат к семейству Lysianassidae. В настоящей работе исследованы 5 представителей этого семейства, потребдяющие трупы из Атлантического и Тихого океанов с целвю изучения адаптаций к их экологическим нишам в хеморецепторном аппарате и пищеварительной системе. Специфическое строение хемосенсорных органов в антеннулах рассматривается как общая преадаптация к хемосенсорной ориентации в отношении пищи, лучше развитая у представителей данной группы, чем у других амфипод. Не найдено существенных различнй в этом отношенин у глубоководных и шельфовых групп. В мандибулах модификации, связанные с приспособлением к питанию трупами животных, привели к далеко зашедшим морфологическим отличиям от традиционной формы, характерной для амфипод. У воех видов пищеварительый тракт адаптирован к приему крупной пищи двумя совершенно разньми и взаимоносключающими способами. У одного рода установлены проресснвные адаптадии кншечника к прнему пищи путем сравнения 1. шельфового и 2. глубоководных видов. Очевидно, что у Lusianassidae две или более днвергентные эволюционные линии привели к развитию эффективных приспособлений к потреблению трупов в глубоководных участках океана.
Carrion (dead oyster) traps were deployed by submersible at depths of 194-212 m on sandy and rocky ridge areas off South Carolina in August 1982 and September 1983. Concurrent benthic sampling by submersible indicated that the sand nondecapod crustacean fauna in both areas consisted primarily of ampeliscid amphipods, the amphipod Unciola irrorata, the isopods Apanthuretta magnifica and Gnathia sp., and tanaids. The trap-drawn necrophagous assemblage of species was similar for all traps in both areas, with the dominant members being the leptostracan Nebalia, undescribed species; the amphipods Tmetonyx cicada, Schraderia mardeni, and Valettiopsis, undescribed species; and the isopod Conilera cylindracea. Similar to necrophages collected by traps in higher latitudes and the deep sea, lysianassid amphipods made up most of the trap fauna (a total of 55.9% of all specimens in this study) and most of the necrophagous species. However, dominance by lysianassids is much lower than that observed in cold-water trapping. Although it may not be true of all nondeep-sea habitats at subboreal or arctic latitudes, when compared with trapping studies in the abyss, this study suggests that taxa other than lysianassids become more important in the consumption of carrion on the upper slope off South Carolina.
Traps baited with meat or fish were set through the ice in 5 m of water near Prudhoe Bay, Alaska. They were monitored by divers and surface observers. Over 99% of the animals attracted to the bait were the lysianassid amphipod Boeckosimus (= Onisimus) affinis (Hansen). Up to 20000 individuals were collected during each 24-h trapping period. Animals moved to the trap only from a downcurrent direction, and from a distance of up to at least 30 m away. It is suggested that chemoreception is the method used to find bait: animals swam into the current after receiving the stimulus and required a constant presence of stimulus at some threshold level to continue moving to the bait.
The structure of the marine invertebrate scavenging guild of a tropical reef ecosystem is investigated here. Baited traps were used as a selective sampling device, focusing attention upon organisms <2 cm in transverse section. Results show that this component of the scavenging guild is very diverse, consisting of 108 species, several of which are extremely abundant. The distribution of the common species varied between reef and sediment habitats. The composition of the guild is fundamentally different from the equivalent guild in cooler waters (such as the polar and deep seas) because of the importance of cirolanid isopods, cypridinid ostracodes and nassariid gastropod molluscs, rather than lysianassoid amphipods. The diversity of members of the guild is interpreted as a reflection of the diversity of habitats and the dynamic environmental conditions of coral reef ecosystems. It is suggested that similar guild structures occur in other tropical and temperate areas. It is also apparent that small marine invertebrates play a more important role as scavengers in tropical areas than previously reported.
A baited trap set on the bottom (4855 m) in the eastern North Atlantic Ocean caught over 600 specimens belonging to 7 species of lysianassid amphipods. Photographic evidence showed a slow build up of numbers and demonstrated fluctuations apparently related to current and pressure changes and to the presence of fish. Length-frequency distributions for the more abundant species reveal size classes related to growth stages. Paralicella caperesca produces a single brood of about 90 eggs. Maturity in this species may be attained in 7 to 11 moults, the precise number possibly being determined by food availability. Orchomene gerulicorbis requires about 11 moults to reach maturity, and females are double-brooded. Mortality within the trap is discussed. A comparison of species of Paralicella and Orchomene based on morphological, developmental, reproductive and ecological characters indicates that the former genus are specialized necrophages whereas the latter are opportunist generalists. The abundance and mobility of necrophagous amphipods indicate that they play a very significant role in the trophic web.