Diversity Of Crustaceans Research Articles

Impact of mangrove defoliation by Hyblaea puera on diversity of associated crustaceans in the Dharamtar Estuary, Maharashtra, India

Mangrove defoliation, caused by teak defoliator moth (Hyblaea puera), has been reported in India and other countries. However, research on its impact on the associated fauna remains limited. We observed extensive mangrove defoliation from August to October 2019 in the Dharamtar Estuary, Maharashtra, India. Consequently, a study was conducted to assess the impact of this defoliation on the diversity of crustaceans within the mangroves and the surrounding estuarine waters. A total of 27 crustacean species were recorded in the mangrove region exhibiting reduced species richness and abundance during the mangrove defoliation period. Whereas, a total of 32 species of crustaceans were recorded from the estuarine region, where both species richness and abundance were higher during the defoliation period. These findings indicate that the crustaceans on the mangrove floor and in the estuarine waters responded differently to the changing environmental conditions caused by defoliation. Keywords: Crustaceans, Diversity, Estuary, Mangrove defoliation, Moth infestation

Decapod crustacean diversity through time and space in a middle-upper Eocene carbonate-siliciclastic platform (southern Jaca Basin, Pyrenees, Spain)

The south-central margin of the Jaca Basin (South-central Pyrenees, Spain) offers well-exposed outcrops ideal for studying the distribution of decapod crustaceans across a mixed carbonate-siliciclastic depositional system during the middle-late Eocene (Bartonian-Priabonian). This study encompasses an area of 1000 km2, featuring environments from siliciclastic coastal plains and deltaic complexes to shallow carbonate and mixed platforms, including coral reefs, extending to prodelta/outer platform deeper conditions. Detailed sampling in four depositional sequences yielded 372 fossil decapod specimens from various lithofacies across 20 localities.Our analysis identifies 39 decapod species within 22 families and demonstrates ecological zonation of decapods in shallow to relatively deep environments. Diversity peaks in siliciclastic shallow proximal prodelta areas and carbonate bryozoan meadows. Species distribution between carbonate and siliciclastic facies is similar, though taxonomically distinct. Articulated specimens predominantly occur in shallow proximal and relatively deep distal siliciclastic areas, linked to sudden sediment input and high sedimentation rates. These findings elucidate the spatial and temporal distribution factors of decapod crustaceans during the middle-late Eocene, contributing to the broader understanding of palaeoecological patterns in mixed depositional systems.

Populations of the stygobiotic amphipod Palearcticarellus pusillus (Martynov, 1930) maintain genetic connectivity between the mountain springs and the deep bottom habitats of Lake Teletskoye (Altai Mountains, Russia)

The diversity of underground fauna is often associated with the presence of karst areas, which have extensive underground cavities and connecting channels. Non-karst areas, however, make up a larger portion of the planet’ surface, and our understanding of the distribution and dispersal abilities of underground fauna in these areas currently remains limited. During a recent study of the diversity of stygobiotic crustaceans in the mountain streams of the Kurai Mountain Range (Altai, Russia), a small-sized species of crangonyctid amphipod, Palearcticarellus pusillus (Crustacea, Amphipoda, Crangonyctidae) was found in high-altitude springs. This species has been previously known only from deep-water habitats in Lake Teletskoye, and molecular genetic analysis revealed that these amphipods maintain genetic connections between the springs and bottom lake habitats. We assume that individuals of this certainly stygobiotic species fall to the bottom of the lake as a result of leaching from tectonic faults connecting these habitats and are not permanent inhabitants of the lake bottom. This hypothesis also suggests that the very small body size of these animals may be related to the narrow crevices and pores of the tectonic faults, rather than neoteny, as it has been previously suggested. The estimated divergence time calculation has also revealed that P. pusillus obviously diverged from its sister species, Palearcticarellus mikhaili from valley springs in Kurai Steppe, ~5 Ma, at the beginning of the Pliocene, possibly due to the uplifting of the Kurai Mountain Range. Subsequent speciation occurred as a result of secondary tectonic activity and changes in groundwater flow, likely during the Pleistocene, approximately 2.7–0.7 Ma. Populations that were isolated for a long time continue to live near mountain springs in the study area.

THE CRUSTACEAN'S EXPORT-IMPORT MAPPING OF FISH QUARANTINE AND INSPECTION AGENCY (FQIA) JAKARTA I ON 2021-2022 PERIOD

Indonesia's crustacean has great potential fisheries business. The depletion of fisheries natural resources needs to be solved to avoid overfishing, especially for crustaceans. The study aim was to analyze crustacean diversity and mapping its products on export and import markets, as well as to analyze the sustainability of crustacean export-import across Indonesia. The study was conducted at FQIA Jakarta I on January until February 2023. The descriptive analysis method was used. The results of the study showed that Indonesia's fisheries export were higher than import activities. On crustacean exports, the highest destination country for lobster (Panulirus sp.) is Cina, the highest destination country for crab (Portunus pelagicus) is the USA, the highest destination country for mud crab (Scylla serrata) is Cina, and the highest destination countries for mantis shrimp (Squilla mantis) are Hongkong and Cina. Meanwhile, for imported crustaceans, snow crab (Chionoecetes opilio) came from Japan, and American lobster (Homarus americanus) came from Canada and USA. The overfishing has not occurred as illustrated for fishing grounds in Indonesia. It indicated by the average of annual catch value which has not higher than MSY catch. Keywords: Crustacea, fish market, fishing ground, annual catch, sustainable.

The relationship between crustacean diversity and population dynamics of Blood Cockle Tegillarca granosa in the coastal area of West Langsa, Aceh Province, Indonesia

Abstract. Mawardi, Sarong MA, Suhendrayatna, Irham M. 2024. The relationship between crustacean diversity and population dynamics of Blood Cockle Tegillarca granosa in the coastal area of West Langsa (Aceh Province, Indonesia). Biodiversitas 25: 690-699. Coastal areas serve as a transitional zone between land and sea, influenced by tidal fluctuations and river estuary currents. Coasts are ideal habitats for spawning and nurturing various crustaceans and bivalves. The aim of this study is to determine the relationship between the Shannon-Wiener diversity index of crustaceans and population dynamics of Tegillarca granosa (Linnaeus, 1758) (Arcidae, Bivalvia) in three different locations. The study utilized a survey method with sampling conducted using transects from the coastline towards the land in coastal areas covered with mangroves, employing transects measuring 5 meters by 5 meters. All samples collected at the study locations were fixed for identification. A total of 1,583 Crustacea individuals belonging to 17 species were sampled. The Shannon-Wiener diversity index of crustaceans ranged from 1.99 to 2.31, categorized as moderate. The highest number of individuals of T. granosa was in November, while the lowest number of individuals was recorded in July. Males of T. granosa were more dominant than females across all study sites. There was a positive correlation between the crustacean diversity index and T. granosa specimens, but a negative correlation with the crustacean dominance index. Seawater salinity, showed a positive correlation with crustacean diversity and the population dynamics of T. granosa.

DNA taxonomy reveals high species diversity among the stygobiont genus Metastenasellus (Crustacea, Isopoda) in African groundwater

This study aimed to explore the species diversity within the isopod genus Metastenasellus in Benin and Cameroon. Compared to other parts of the world, the described diversity of stygobiotic crustaceans in Africa is low due to a dearth of studies and taxonomic expertise. However, recent research activities in Benin and Cameroon suggest higher groundwater diversity than previously envisioned. Recent sampling campaigns in these countries have shown that Metastenasellus is a major group in the underground aquatic environment. The accumulation of biological material provided an opportunity to explore species diversity within the genus using a DNA taxonomy approach based on the cytochrome c oxidase subunit I (COI) gene fragment. Despite the limitations of using a single-locus approach for species delimitation, an overview of the diversity within the genus Metastenasellus was obtained, revealing the presence of 23 distinct lineages. Several elements suggest that most, if not all, of these lineages represent valid species. These include high genetic distances between lineages, morphologically distinct species separated by genetic distances of the same order of magnitude as between other described lineages, and the coexistence of different lineages at the same stations. Despite a limited sampling effort, these first results indicate a high level of species diversity and endemism within Metastenasellus in the studied regions. The narrow geographic distribution of the lineages suggests strong isolation and limited dispersal abilities. This study highlights the potential for discovering a significant number of new species within this genus and emphasizes the need for further research to uncover the extent of diversity in African stygobiotic isopods.

Impacts of Freshwater Fish Sanctuaries on Fish and Crustacean Diversity, Catch, and Household Income of Fisherfolk in Baggao, Cagayan, Philippines

The study was conducted from February to March 2022 to assess the impacts of fish sanctuaries on fish and crustacean diversity, catch, and income of fisherfolk in Baggao, Cagayan. Data were collected from the 59 registered fisherfolk in the study areas using a structured survey instrument and were analyzed using descriptive methods. The Shannon-Weiner Diversity and Pielou indices were computed to determine fish diversity and evenness, respectively. The results showed that the diversity indices in the three study areas were 1.91 in Duba Cave, 1.66 in Hot Spring, and 1.58 in Bluewater Falls, and the average species evenness was 0.7. Further, the major species caught include Anguillasp., Oreochromis sp., Trichopodus sp., Crenimugil sp., Macrobrachium sp., Ciprinus sp., Clarias sp., Arius sp., Chana sp., Glossogobius sp., Sundathelphusa sp., Hyphorhamphus sp., and Gambusia sp. The volume of fish catch depends on the production space in the buffer zone, the time of fishing or fishing frequency, and the fishing gears used by the respondents. The sanctuaries also served as alternative livelihood and source of income for the respondents with the development of tourism, which provided jobs (e.g., tour guides, river wardens, project monitors, and laborers) to community residents. The study's results confirmed the positive impacts of fish sanctuaries on the diversity, catch, and household income of fisherfolk.

Diving into Diversity: Copepod Crustaceans in Octocoral Associations

This research provides an extensive analysis of the biodiversity and distribution patterns of copepod crustaceans associated with octocoral species. A comprehensive dataset comprising 966 records pertaining to 233 copepod species, encompassing 54 genera, 18 families, and 3 orders, was compiled from 92 scientific papers published between 1858 and 2023, and updated as open data to GBIF. These copepods were found to be closely associated with 183 octocoral species, representing 72 genera and 28 families. The analysis revealed a total of 393 distinct interspecific associations between copepods, classified under the orders Cyclopoida, Harpacticoida, and Siphonostomatoida, and diverse octocorals. Approximately 60% of these associations were reported only once in the literature, which poses challenges to assessing the level of host specificity among the majority of copepod species linked with octocorals. Notably, over 91% of the recorded copepod species were found at depths not exceeding 30 m, with only four copepod species reported at greater depths surpassing 500 m. The presence of these symbiotic copepods was documented across 215 sampling sites situated within 8 of the 12 defined marine ecoregions, with particular attention to the Western Indo-Pacific, Central Indo-Pacific, and Temperate Northern regions. Despite the comprehensive examination of available data, this study highlights substantial gaps in our comprehension of copepod crustacean diversity and distribution in association with octocorals. Moreover, crucial information concerning symbiotic copepods is conspicuously absent for approximately 94% of potential octocoral host species. These disparities emphasize the imperative need for further scientific inquiry to unveil the intricacies of symbiotic relationships and to contribute to a more holistic understanding of copepod–octocoral associations.

Taxonomic Diversity and Spatial Distribution of Crustaceans in an Aquatic Ecosystem Classified as a Ramsar Site: The Merja of Fouarat (Kenitra, Morocco)

Taxonomic Diversity and Spatial Distribution of Crustaceans in an Aquatic Ecosystem Classified as a Ramsar Site: The Merja of Fouarat (Kenitra, Morocco)

An Aptian sponge-associated decapod crustacean assemblage from Cal Cassanyes (Catalonia, north-east Iberian Peninsula): Taxonomy and palaeoecological implications

A highly diverse decapod crustacean fauna is described from the classic Aptian outcrop of Cal Cassanyes (Castellet i la Gornal) in Catalonia. Although decapod crustaceans are a minor component of the rich invertebrate assemblages at that locality, the just over fifty specimens collected comprise sixteen taxa assignable to the Macrura, Anomura and Brachyura. Of these, the last-named are the most prominent group, comprising eleven species, representing seven families, inclusive of one representative of the Eubrachyura. On the basis of this material, two new genera and five new species are erected, namely Pagurus? garrafensis sp. nov., Garrafosopon gen. nov. angustus (Wright and Collins, 1972) comb. nov., Vectis blesai sp. nov., Mesodromilites prietoi sp. nov., Necrocarcinus mariae sp. nov. and Iberodorippe vinea gen. nov., sp. nov. In addition, Hoploparia sp., an indeterminate axiid and one paguroid, as well as one indeterminate galatheoid are recorded here. Material of Distefania incerta (Bell, 1863), the commonest species at the study site by far, of Goniodromites laevis (Van Straelen, 1940) and of Etyxanthosia fossa (Wright and Collins, 1972) represents the first Aptian and stratigraphically oldest records for these taxa. Added to this list are also Eodromites sp., Paranecrocarcinus? sp. and Pseudonecrocarcinus? sp. The high decapod crustacean diversity at Cal Cassanyes establishes this locality as the richest Aptian assemblage from the Iberian Peninsula, but also one of the richest in the world. The faunal assemblages here are dominated by sponges, and the varied composition of the decapod crustacean faunas can be linked to upwelling currents which provided abundant nutrients. In fact, the establishment of sponge communities played a crucial role in activating the food chain and functioned similarly to a patch reef, creating a relatively sheltered environment that facilitated the colonisation of other invertebrate communities, including decapod crustaceans. The latter occupied various trophic levels as both primary and secondary consumers. Current knowledge of Early Cretaceous decapod crustaceans is scant and hinders a thorough palaeobiogeographical analysis. The present study emphasises the challenges surrounding the identification of endemic taxa, thus impacting our understanding of decapod crustacean palaeobiogeography of the late Early Cretaceous.

Diversity and distribution of crustaceans in the mangrove forest of Nusa Lembongan, Bali, Indonesia

Abstract. Ginantra IK, Muksin IK, Joni M, Wijaya IMS. 2023. Diversity and distribution of crustaceans in the mangrove forest of Nusa Lembongan, Bali, Indonesia. Biodiversitas 24: 4533-4541. Research on the diversity and distribution of crustaceans in the mangrove forest of Nusa Lembongan, Bali, Indonesia was conducted from March to June 2022. Sampling was carried out using the quadratic method at seven mangrove forest sites. The identification of crustacean species is based on morphological characteristics, namely carapace color, claw shape, legs, and body size. Crustacean density was determined based on the number of individuals per unit area of mangrove forest, diversity was determined by the Shanon-Wiener Index, and crustacean distribution was determined based on the frequency of species presence in each square at the seven study sites. Environmental factors were also measured: Mangrove vegetation, substrate type, temperature, pH, and salinity. The results showed that 12 species of crustaceans were found, consisting of 10 species of crabs and two species of hermit crabs. Several species of crabs are quite dominant in the mangroves of Nusa Lembongan namely Sesarma pictum (De Haan, 1835), with a density of 7 individuals/5 m2, Uca tetragonon (Herbst, 1790) of 3.7 individuals/5 m2, Uca rosea (Tweedie, 1837) with a density of 2.5 individuals/ 5 m2, and Uca triangularis (A. Milne-Edwards, 1873) with a density of 2 individuals/5 m2. Environmental factors support the life of Nusa Lembongan crustaceans, namely the type of substrate, mostly muddy and sandy, diverse species of mangrove plants, both true and associated mangroves, water temperature 27.70-29.00°C, pH 6.88-7.15 and water salinity ranging from 27.83-31.53‰. Crustacean diversity is included in the moderate category with their diversity index. There are three crab species with moderate to frequent (absolute) frequency of presence, namely U. rosea (Fi: 57.15%), S. pictum (Fi: 71.43%), and U. tetragonon (Fi: 85.71%). These species are present in four to six mangrove forest sites.

Phototropic Behavioral Responses of Zooplankton in Lake Baikal In Situ and during the Anthropogenic Impact Modeling

Earlier, we showed that the registration of the behavioral responses of autochthonous mesozooplankton communities in situ is a more dynamic methodological approach in the biological assessment of the environmental well-being of aquatic ecosystems, as well as an alternative method to generally accepted tests on mortality and immobilization. The change in behavioral responses, including phototropic responses, may occur at lower concentrations of pollutants, leading to the inhibition of the risk-avoidance response of predatory fish attack and, ultimately, to the change in zooplankton abundance and biodiversity. The biological significance of such changes is quite high since zooplankters form the basis of food chains. This work studies the possibility of biomonitoring the quality of fresh water in Lake Baikal according to the state of the autochthonous mesozooplankton community in summer and winter using a digital holographic camera developed and tested by us in laboratory conditions. This method makes it possible to determine the concentration of plankters in the controlled volume of the DHC and perform photostimulation with different levels of illuminance. The depth profilometry of the phototropic response was compared with the profilometry of plankton concentration, intraspecific diversity of crustaceans according to the Pielou index, and the results of catching using the Juday net in the natural environment of the lake and during the modeling of the anthropogenic impact (introduction of table salt solution into the local area close to the registration probe). The circadian rhythm parameters were determined by the spectral analysis of the long-term registration of the phototropic response dynamics. It was noted that the inhibition of the phototropic response was the most adequate marker of the exogenous impact and the appearance of an alternating factor among the studied indicators of the state of the plankton community, namely, intraspecific diversity, synchronism of circadian rhythms, and response to paired photostimulation. The revealed patterns of behavioral responses of autochthonous zooplankton in natural and artificially modified conditions will allow for the implementation of long-term continuous control over the environmental well-being of water areas, including the collection ponds of treatment facilities, cooling ponds of nuclear power plants, and other water areas in contact with potentially hazardous facilities. The comparison of the identified patterns with the behavioral responses of euryhaline mesozooplankton will expand this method to assess the well-being of salt-water and marine reservoirs under the anthropogenic impact and will make it possible to create a continuous monitoring system.

Marine and estuarine crustacean diversity and assemblage structure in eastern Brazil three years after the Fundão mining dam failure

The present study investigates the spatial and temporal patterns of species richness and assemblage structure of decapod and stomatopod crustaceans in the area impacted by the Fundão dam collapse (Rio Doce basin, Brazil) in November 2015. From October 2018 to September 2019, monthly bottom-trawl samples were collected in estuarine and marine waters of the Rio Doce (directly impacted area) and three other localities. Forty-one crustacean species were recorded, with the overall community structure dominated by six species. The seabob shrimp Xiphopenaeus kroyeri was the most common species, with the coastal marine area near to the Rio Doce mouth being an important fishery ground. Species composition changed significantly among localities, habitats, and seasons, with marine and estuarine assemblages shaped by freshwater discharge. Distribution patterns of species were significantly influenced by the environmental variables potentially altered by tailings, such as turbidity and pH. Species richness and abundance differed among localities; as expected, they were generally higher on the inner shelf than in estuaries and higher during the dry season than the rainy season. Due to the lack of information before the disaster, the low number of species found in the Rio Doce estuary cannot be solely attributed to the disaster but also its freshwater condition. This is the first broad study of the estuarine and coastal marine decapod and stomatopod crustaceans in the region, and we suggest the need for long-term monitoring considering that the effects of this disaster are not easy to detect and probably need multi-year study to be evidenced.

Assessing spatial and temporal changes in diversity of copepod crustaceans: a key step for biodiversity conservation in groundwater-fed springs

Despite the close attention springs have received from a hydrologic perspective and as biodiversity hotspots, the multiple dimensions of spring meiofaunal assemblage diversity are still poorly investigated. Knowledge of beta diversity patterns and drivers can inform and improve management decisions on biodiversity conservation. Here, we analyzed beta diversity of copepod assemblages in karst springs in Central Italy by focusing on: 1) relative contributions of turnover and nestedness components to taxonomic and phylogenetic beta diversity; 2) temporal variation of species richness and beta diversity within and between the target springs in conjunction with models of the influence of physical-chemical parameters on within-spring diversity changes; 3) expected risk of habitat loss due to variation in groundwater recharge under climate change. To this end, we gathered data from 168 samples collected in four karst springs from 2004 to 2016. Overall, we found 48 copepod species, 22 of which are obligate groundwater dwellers while the remaining 26 usually occur in surface freshwaters. All springs showed significant changes in taxonomic and phylogenetic beta diversity over time. Total beta diversity was high for both the taxonomic and phylogenetic dimensions, and turnover was the main component. Inter-site variability in dissolved oxygen explained a noticeable part of temporal variation in beta diversity, likely reflecting the role of microhabitat heterogeneity in shaping site-specific assemblages. However, most of the temporal variation in species richness and beta diversity remained unexplained, suggesting a major role of other factors, such as seasonal discharge variations. Modelling of recharge rates for all the four springs over 2001–2020 suggested a potential >40% recharge deficit under dry conditions. Moreover, Cellular Automata-based modelling of rainfall over the Gran Sasso-Sirente hydrogeologic unit (feeding three of the four springs) predicted an overall precipitation decrease in the 2081–2095 period. Such changes could produce severe effects on springs’ microhabitats and related communities. Our results indicate that partitioning beta diversity, monitoring its temporal changes and assessing its environmental drivers are critical to evidence-based conservation of springs. Particularly, the high species turnover we have observed suggests that conservation strategies should seek to preserve as many microhabitats as possible within and among karst springs.

Species diversity and abundance of mobile crustaceans associated with living and dead colonies of the invasive sun coral Tubastraea

Species diversity and abundance of mobile crustaceans associated with living and dead colonies of the invasive sun coral Tubastraea

Keanekaragaman Crustacea Ordo Decapoda Di Kawasan Mangrove Pangkal Babu Desa Tungkal 1, Tanjung Jabung Barat

Mangrove area is a type of ecosystem with unique characteristics. Mangrove ecosystems are located in brackish waters which are a meeting place between land and sea. Mangroves have an ecological function as a habitat for various types of fauna. In addition, many mangrove areas have been developed as ecotourism areas which have impacts on the environment such as the risk of damage to existing natural resources and the survival of one of the fauna that makes up the mangrove ecosystem, namely Crustaceans. The purpose of this study was to identify the diversity of Crustaceans of the Decapoda Order in the mangrove area of Tungkal 1 Village, Tanjung Jabung Barat. This research method is descriptive quantitative. Sampling was carried out exploratively using purposive sampling technique. Sampling was carried out at three stations using four types of fishing gear, namely spread nets, gill nets, sondong and togok carried out 3 repetitions on different days. The research results obtained found 15 species from 8 families including 10 species of shrimp and 5 species of crabs. The diversity index obtained as a whole is in the medium category and dominance index at each station is included in the low category.

Diversity of Penaeidae at the Mengkudu Bay Waters, North Sumatra, Indonesia

Abstract. Azwar E, Sularno, Waruwu FP, Tarigan MRM, Ulfa SW, Djaingsastro AJ. 2023. Diversity of Penaeidae at the Teluk Mengkudu Waters, North Sumatra, Indonesia. Biodiversitas 24: 1376-1384. Microscopic animals play an important role in the growth of marine biota. Crustaceans are a marine biota group often found in waters and have high economic value. Crustaceans also have a significant role in coral reef ecosystems, contributing around 20% of all invertebrate species. Crustaceans are an important group of microbenthic fauna in coastal ecosystems, ranging from mangroves, coral reefs, and seagrass ecosystems. This present study was conducted from April to June 2022 to identify Penaeidae diversity in Teluk Mengkudu waters, Serdang Bedagai District, North Sumatra Province, Indonesia. Furthermore, it used a purposive sampling method to harvest crustacean species near the waters. An exploratory method was applied with quantitative data collection to select Penaeidae crustaceans from the catches retrieved by fishermen. The tools used in this study were boat, net, fiber, knife, compass, flags, camera, notebook, ice cubes, a thermometer, pH meter, and DO meter. The material used in this study was shrimp caught by fishers. Data collection techniques used interviews and documentation with fishing communities about catching crustaceans at the study site. Data analysis uses the formula diversity, evenness, knowledge richness, and dominance index. Based on the results, Penaeus indicus H.Milne Edwards, 1837 and Metapenaeus ensis (De Haan, 1844) were the two species obtained from the Penaeidae family. The evenness index for P. indicus and M. ensis was respectively highest in June (0.237 and 0.519) but lowest in May (0.203 and 0.510) with a total value of 2.212. Also, the prominent richness index for both species was respectively highest in June (5.762 and 29.371) but lowest in May (4.568 and 27.053). The highest dominance index (D) was measured in May, where the highest D value of P. indicus was 0.003, and the lowest was 0.002. The highest D of M. ensis was discovered in June, namely 0.086, while the lowest, at 0.073, was recorded in May, and in general, both species had a total D of 0.245. Parameters of salinity, pH, temperature, substrate, and oxygen strongly influence crustacean diversity. The parameters measured in the study area included temperature (28?), salinity (20-35 ppt), DO (6.8 mg/L), and pH (6.7).

What Lies Inside a Dead Coral: Diversity of Reef-Associated Cryptic Crustacean (Crabs: Anomura and Brachyura) from Different Habitat Characteristics in Tidung Islands, Indonesia

Highlight Research The very first attempt to investigated and revealing biodiversity of crustacean crab in coral reef ecosystem at Tidung Island, Indonesia Conservation area (Tidung Kecil) has more abundant crab species than tourism area (Tidung Besar). A microhabitat that suffers anthropogenic pressure may alter the composition of crustacean biodiversity, especially in crab group. Different characteristics and complexity of coral habitat affect the dynamics of cryptic crustacean communities Abstract Recent studies have been widely carried out on the important role and ecological function of coral reefs. However, little attention has been given to small and cryptic crustaceans organisms living within different microhabitat in dead corals. This study aimed to reveal the diversity of crustaceans that inhabit dead corals in Tidung Islands, Indonesia. A total of 134 individuals from 41 species in 13 families were recorded within eight dead corals taken from two different sites. Furthermore, the species identified from Tidung Kecil were significantly different and more diverse than Tidung Besar. It was suggested that differences in anthropogenic pressure between Tidung Besar and Kecil might have an important role in the spread of crab crustaceans’ organisms. Xanthidae from infraorder Brachyura were observed to be the most dominant family, while Galatheidae and Porcellanidae from infraorder Anomura spread almost equally in both sites. Additionally, Psaumis cavipes and Chlorodiella nigra were species with the largest contribution of crab crustaceans’ communities in the death of coral’s ecosystem in the Tidung Islands. This result indicated that dead corals might play a key role in supporting and providing a habitat for crustacean cryptic.

Study of the abundance and diversity of crustaceans in the ecosystem mangrove forest of Ambon Island

Crustaceans are very abundant in mangrove forest ecosystems and are still poorly documented. Therefore, this study aims to reveal the abundance and diversity of crustaceans in the mangrove forest ecosystem of Hutumuri Beach and Suli Beach, Ambon Island. Crustacean data collection was done by determining the plot using random sampling method. Determination of crustacean abundance using individual formulations per unit area or per unit volume, while crustacean diversity was calculated using the Shannon-Wiener equation. The crustaceans found in the mangrove forest ecosystem of the Hutumuri and Suli beaches were 56 individuals, consisting of 7 families and 11 species. The abundance of crustaceans in the mangrove forest ecosystem of the Hutumuri coast and the coast of Suli was 0.29 ind/m2 and 0.27 ind/m2, respectively. For the diversity of crustacean species in the mangrove forest ecosystem of the Hutumuri coast and the Suli coast, respectively, 1, 176807 in the medium category and 0.78526 in the low category.

Effects of Spartina alterniflora invasion on the functional groups and niche of benthic crustaceans and fishes in mangrove wetland.

To investigate the effects of Spartina alterniflora invasion on mangrove wetland ecosystem, the benthic crustacean and fish samples were collected using cage nets in Zhangjiang Estuary Mangrove Wetland, Fujian Pro-vince in August 2020, January and April 2021. The five sampling sites included two mangroves (Avicennia marina and Kandelia obovata) sites, two S. alterniflora sites, and one mudflat site. The abundance, biomass, index of relative importance (IRI), Shannon diversity index (H), Pielou evenness index (J), and Margalef richness index (D) were used to quantify the dominant species and species diversity of benthic crustaceans and fishes. The functional groups and niche of dominant species were also analyzed. A total of 37 species, from 2 phyla, 2 classes, 8 orders, and 17 families, were identified across the three seasons. Most of them were warm-water and euryhaline species, mainly carnivorous and omnivorous functional groups. The results of two-way analysis of variance and NMDS showed that the community diversity index of benthic crustacean and fish did not change significantly after the invasion of S. alterniflora compared with mudflat. Functional groups had changed significantly, with the species number of plankton functional groups, carnivorous and phytophagous functional groups being increased. Compared with mangrove sites, the number of species of benthic crustacean and fish in S. alterniflora sites was significantly increased. The spatio-temporal niche breadth of dominant species ranged from 0 to 1.4186, with Liza carinata (1.4186), Bostrychus sinensis (1.0168), Metapenaeus ensis (0.9469) and Exopalaemon carinicauda (0.8922) as the top four species.