Halocyprid Ostracods of the Arabian Sea Region
Abstract and Figures
The taxonomy and distribution of halocyprid ostracods from the Arabian Sea Region is reported, based upon samples collected in the Northwestern Indian Ocean within the framework of the Netherlands Indian Ocean Program (NIOP: 1992-1993), the U.S. Joint Global Ocean Flux Study (U.S. JGOFS: 1994–1996), and the U.S. Global Ocean Ecosystem Dynamics program (U.S. GLOBEC: 1995).
Forty-one species from the following genera belonging to the family Halocyprididae are described, illustrated, and representative photographs are presented: Archiconchoecia, Alacia, Conchoecetta, Conchoecia, Conchoecilla, Conchoecissa, Discoconchoecia, Loricoecia, Mikroconchoecia, Orthoconchoecia, Paraconchoecia, Paramollicia, Platyconchoecia, Porroecia, Proceroecia, Pseudoconchoecia, Clausoecia, Kyrtoecia, Nasoecia and Euconchoecia. For fourteen species, members of the genera Macroconchoecia, Mollicia, Paraconchoecia, Metaconchoecia, Mülleroecia, Fellia, Halocypria and Halocypris, only carapace outlines are presented. Keys to the subfamilies, tribes, genera and species, and patterns of horizontal and
vertical distribution of each described species in the Arabian Sea Region are also given. The data on occurrence of halocyprid species at each of the stations during the investigation period and the depth ranges of halocyprid species found in the analyzed material but not described in the present book are listed in appendices.
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... Archiconchoecia striata were originally described for the Mediterranean Sea, and its distribution was later extended to subtropical and tropical latitudes of the Atlantic, Indian and Pacific oceans (Deevey 1968, Angel et al. 2008. It is a mesopelagic species with a shallow distribution, whose highest abundances are between 50-150 m of depth (Drapun & Smith 2012). A. striata have been found in the Sargasso Sea in Bermuda and the Adriatic Sea, over 500 m depth throughout the year (Deevey 1968, Brautović et al. 2018. ...
... This species, which was the most abundant and with the highest frequency of occurrence, has also been reported among the most abundant and frequent off the coast of Peru (Castillo et al. 2007), as well as in the Arabian Sea (Drapun & Smith 2012) and the Adriatic Sea (Deevey 1968, Brautović et al. 2006, 2018. ...
... These authors found C. giesbrechti preferably in tropical areas of the Atlantic, over 200 m deep. Drapun & Smith (2012) also found that it is more abundant above 200 m depth in the Arabian Sea, smaller in size, and slight differences in the mandible endopod setation than specimens of this species reported by Martens (1979) off the coasts of Chile. ...
In the north-central zone of Chile (25°00’-31°40'S), zooplankton samples were taken in 103 oceanographic stations during February-March 2017 (0-70 m). Ostracods were separated, identified, and counted, making it possible to determine their distribution, abundance, species richness, and diversity. Twenty-one species belonging to 12 genera of the Halocyprididae family were identified, three of which had not been previously reported for the southeastern Pacific (Conchoecetta acuminata, Mikroconchoecia stigmatica, and Orthoconchoecia atlantica). The highest abundances, species richness, and diversity were found mainly in stations away from the coast (10 and 20 nm), sampled in hours of darkness. The most abundant species with the highest frequency of occurrence were Archiconchoecia striata, Conchoecetta giesbrechti, Conchoecia magna, and Halocypris inflata. A. striata constituted more than 50% of the total abundance of the ostracods identified.
... The collected ostracods were hand-sorted and separated into different species. They included both adults and various juvenile instars, which were identified based on published records (Angel 1971;Angel 1993;Drapun & Smith 2012). ...
... Setae and appendages terminology follow Drapun & Smith (2012), except for the most posterior appendage (uropodal lamella) that follows Meisch (2007). ...
... Sixth limb (Fig. 6D). Overall morphology of this limb very similar to Drapun's (2012) illustration of the limb of P. procera, especially the number, location and size of the setae. All three of the terminal setae have long terminal sensilla. ...
Two new planktonic ostracods of the genus Proceroecia Kock, 1992, P. hwanghaensis sp. nov. and P. joseondonghaensis sp. nov., collected from neritic waters off the south coast of South Korea are described. Morphologically, they are similar to P. microprocera (Angel, 1971), the type species of the genus, but show several clear morphological differences, most prominent being the shape of the male endopodite on the second antenna and the presence of a sensilla on the coxale of the fifth limb. The two new species have subtle differences, such as the length of the frontal organ, number of spines on the comb-like e-seta on the first antenna in males, number of spinules on the b-seta on the second antenna in females, etc. Sequences derived from partial mitochondrial cytochrome oxidase c subunit 1 (mtCOI) for these novel species have been compared with sequences available for other Proceroecia species on GenBank, including P. microprocera. These comparisons suggest that both new species are distinct taxa. They also indicate that one set of sequences on GeneBank previously attributed to P. microprocera and derived from material collected from Chinese waters, belong to P. hwanghaensis, and that another set of sequences of an unidentified Proceroecia species from the South China Sea can be attributable to P. joseondonghaensis. Hence, these new species occur widely in the neritic waters of East Asia. The present study increases the number of the known Proceroecia species to nine, and the numbers of halocyprid ostracod species recorded from Korean waters to six.
... Leveau (1967) also reported on a collection of halocypids from the Arabian Sea, and there have been a few follow-up studies of the halocyprids (James, 1975, George and Nair 1980, Nair and Madhupratap, 1984. Information about the region's planktonic ostracod assemblages remained sparse until Drapun and Smith (2012) published their excellent monograph summarising the halocyprid results from the 1995 JGOFS Indian Ocean Experiment (Smith and Madhuptratap, 2005). Their sampling using a MOC1 sampler was limited to the upper 1000m, but their geographical coverage was extensive. ...
... Three others are poorly known (Fellia dispar, Bathyconchoecia georgei and Mollicia minki), and a fourth (Halocypretta striata Müller, 1906) has been recently been re-described (Angel, 2013). Drapun and Smith (2012) samples had a broad geographical coverage, but were restricted bathymetrically to the upper 1000 m, and resulted from the filtration of much smaller volumes of water. Their MOC1 sampler was fitted with a much finer mesh 200 µm mesh compared to the 320 µm mesh of the RMT I. ...
... So their samples included many more of the early instars that cannot be identified to species. We record several species were not reported by Drapun and Smith (2012), the majority of which were collected at depths >1000 m (marked † in Table 3). ...
... Species determination was performed by stereomicroscope (Carl Zeiss) and inverted microscope (Olympus IMT-2) at magnifications of 40x, 100x and 400x. Ostracods were identified according to species descriptions given by MŰLLER (1912), SKOGSBERG (1920), POULSEN (1973), ANGEL (1993) and DRAPUN & SMITH (2012). The number of individuals was determined beneath the square meter (ind.m -2 ) of the water column. ...
... Among 26 species recorded in the mixed layer of the North-eastern Arabian Sea (Indian Ocean), Cypridina dentata, Euconchoecia aculeata, Conchoecia subarcuata and Orthoconchoecia atlantica are dominant during summer monsoon (PURUSHOTHAMAN, 2015). Forty-one (41) spe-cies belonging to the family Halocyprididae have been described by DRAPUN & SMITH (2012), in the North-western Arabian Sea. Sixteen (16) species of halocyprid ostracods have been identified in the Humboldt Current ecosystem off Peru . ...
Rad donosi prve sveobuhvatne rezultate o taksonomskom sastavu vrsta, sezonskoj i horizontalnoj raspodjeli zajednice planktonskih ljuskara u otvorenim vodama cijelog Jadranskog mora. Uzorci su prikupljeni tijekom oceanografske ekspedicije “Andrija Mohorovičić” (1974.-1976.) tijekom četiri godišnja doba na 35 postaja, raspoređenih u osam poprečnih transekata na sjevernom, srednjem i južnom dijelu Jadranskog mora. Taksonomski je određeno petnaest vrsta i dvije podvrste planktonskih ljuskara iz porodice Halocyprididae. Dominantne su vrste bile: Archiconchoecia striata,Porroecia spinirostris i Proceroecia macroprocera . Pored toga, vrsta Paraconchoecia oblonga je po prvi put zabilježena u Jadranskom moru. Najveća abundancija i bio-raznolikost ljuskara je zabilježena u dubokom južnom Jadranu, dok su bili rijetki u plitkom području sjevernog Jadrana. Kao prijelaznu zonu između ova dva područja, srednji Jadran karakterizira velika bio-raznolikost i kratkotrajna dominacija planktonskih ljuskara u zooplanktonskoj zajednici. Njihova horizontalna raspodjela u Jadranskom moru može se povezati s periodičnom ingresijom istočno-mediteranske vode i vrtložnim strujanjima, posebice u područjima srednjeg i južnog Jadrana.
... Inna's classification and distribution research on planktonic ostracods produced an up-to-date, yet user-friendly identification guide for halocyprid ostracods in the Arabian Sea with the detailed bathymetric distribution down to 1500 m deep (Drapun & Smith, 2012). Yin and Chen (1991) reported species composition, abundance and diurnal vertical distribution of planktonic ostracods in the southern South China Sea (SCS) to depth of 2600 m. ...
The vertical distribution of species richness, abundance and biomass of planktonic ostracods down to a depth of 1000 m were studied in the northeastern South China Sea (NESCS) during March and in the central South China Sea (CTSCS) during September 2016. A total of 47 species of halocyprids were identified, with 46 species recorded in the NESCS and 28 species in the CTSCS. Most of the species observed were concentrated in the mesopelagic zone (200–1000 m), but the majority of species abundance and biomass occurred in the 25 m to 300 m water column. Results of statistical analysis showed that the vertical distribution of planktonic ostracods was associated with chlorophyll a concentration and sampling depth. The high abundance and species richness of ostracods in the NESCS were probably influenced by the Kuroshio intrusion and eddies leading to high levels of chlorophyll a concentration. The biomass of large‐sized individuals with low abundance is equal to or larger than, the extremely small‐sized individuals with high abundance, particularly in deep layers. The body sizes of planktonic ostracods were found to increase from surface to deeper water layers, indicating a trend of greater body length and higher biomass of ostracods in deep sea.
... They carapace outline is very similar to that of C. plinthina. Detailed examination of the specimens showed they are not conspecific with any of the previously described Conchoecissa species (Müller, 1906;Chen & Lin, 1995;Chavtur, 2003;Chavtur & Angel, 2011;Drapun & Smith, 2012). For example, in comparisons between the specimens and the known Conchoecissa species (Table 1), it is obvious that the specimens are prominently bigger than known Conchoecissa species, and about 10% longer than C. plinthina, which is the biggest species of genus Conchoecissa, but the percentage of the 1st antenna to carapace is very much smaller in the novel species than in C. plinthina (about 49.0%: 71.4%, respectively). ...
Pelagic ostracods are one of the main groups of zooplankton and are abundant in marine ecosystems worldwide. The record of marine planktonic ostracod species in the central and southern part of the South China Sea accounts over for one-third of the total recorded marine planktonic ostracods in seas around China. In this study, we examined and compared the specimens from a recent cruise in this region that appeared to be different from previously described species of genus Conchoecissa , and then confirmed them as a new bathypelagic species Conchoecissa nigromaculatus . These specimens clearly differed from the other species of genus Conchoecissa with differences observed in the size, carapace, locations of glands, mandible, maxilla, sixth limb, and furca. In this species, mandibular coxal endite has no ventral finger process, maxilla has prominently large endites and has only two claws on the tip, the sixth limb has very simple endites, and this species has distinctive features not previously observed in the tribe Conchoeciini before. It is therefore necessary to emend the diagnosis of this group.
... Most of the ecological studies have been done in the Chilean waters (Martens 1979), Atlantic (Angel et al. 2007) and in the Humbolt current off Peru (). In the Arabian Sea, a recent study has been conducted on halocyprids by Drapun & Smith (2012). In the northeastern Arabian Sea, no detailed ecological studies have been undertaken on marine planktonic ostracods till now. ...
Planktonic ostracods contribute significantly to the biomass of zooplankton in the Arabian Sea with an unusually high density due to swarming. However, due to the small size, their abundance is often underestimated. In this paper, the diversity of planktonic ostracods in the mixed layer depth of the northeastern Arabian Sea in relation to environmental parameters during the summer monsoon is presented. The mean abundance in the mixed layer depth was very high. About 26 species belonging to 17 genera representing two families were recognized. Out of this, 25 species belonged to (3 sub families, 16 genera) the order Myodocopa and one to the order Myodocopida. The dominant species were Cypridina dentata, Euconchoecia aculeata, Conchoecia subarcuata and Orthoconchoecia atlantica. Cypridina dentata and Euconchoecia aculeata contributed to about 89% of the total abundance. The results suggest that the distribution and diversity of ostracods were very much influenced by the hydrographic conditions of the Arabian Sea during the summer monsoon.
... The terminology used below follows Drapun & Smith (2011). ...
Discoconchoecia elegans (Sars, 1865) is one of the most frequently recorded species of halocyprid ostracods and specimens are collected in abundance from various latitudes throughout the world oceans. This species is often dominant or subdominant member of the mesopelagic assemblages. However, its body size varies substantially with latitude, posing the question as to whether D. elegans is either a single, highly variable species, or a complex of cryptic and sibling species. Evaluation of the hypothesis that D. elegans is a complex of species requires comparison between the type material and specimens collected from different latitudes. The inadequacy of the original description from the type locality, off the Lofoten Islands (NW Norway), combined with a lack of the type material is preventing critical rating.
In this paper Discoconchoecia elegans is redescribed from specimens collected from an area close to Svalbard, using detailed drawings, morphometric measurements of all limbs, and SEM photographs, and it is compared with specimens collected from an area close to the species type locality. The individuals from those two localities show no significant differences, probably because the hydrographic conditions are similar between the two sites.
... The fishery is a vital component of national food security, and future expansion and diversification of the fishery are cornerstones of government planning for the sector (Ministry of Agriculture and Fisheries 2013). Knowledge of the biodiversity of marine organisms in the region is slowly increasing but is developed for only a few groups, notably fish (Al-Jufaili et al. 2010), corals (Claereboudt 2006), macro-algae (Price et al. 2006), copepods (Prusova et al. 2011), ostracods (Drapun and Smith 2011), and phytoplanktonic organisms (Al-Hashmi et al. 2012). Little is known of many of the invertebrate groups, including some of which are of particular interest to natural product chemists, e.g., tunicates and sponges. ...
With its diverse, living marine resources and rapidly growing educational and research infrastructure, the Sultanate of Oman is well-positioned to take advantage of the commercial opportunities presented by marine biotechnology. In recognition of potential development, an international symposium, Marine Biotechnology-Emerging Opportunities and Future Perspectives, was held in Muscat, November 12-13, 2013. Three keynote addresses were given, 23 oral presentations made, and a poster exhibition held. The final session reviewed national and regional issues, and the delegates agreed informally on a number of future actions. The potential for future development of marine biotechnology was recognized by all delegates, and following the symposium, they were surveyed for their views on how best to sustain and develop new activities. One hundred percent of respondents found the meeting useful and would support future symposia in the region. Fifty-one percent of Omani respondents recognized major organizational challenges and obstacles to the development of marine biotechnology compared with 23 % of overseas respondents. The need for greater collaboration between research institutions within the GCC region was recognized by 98 % of all respondents. The presentations and survey outcomes are reviewed in this paper.
Ostracods (Crustacea, Ostracoda) are small bivalved crustaceans, contributing to the marine zooplankton community. They are widely distributed and are relatively abundant components of the marine mesozooplankton worldwide, playing an important role in the transport of organic matter to deep layers. By analysing the mitochondrial COI gene, we explored the population genetic structure and haplotype pattern of Porroecia spinirostris which is the dominant ostracod in the South China Sea. We investigated the population genetic structure of ostracods at medium spatial scales in the absence of physical barriers. Our data provides evidence of the importance of both long-distance dispersal as well as genetic isolation in determining the seascape genetic structure of this species. Our data suggest that P.spinirostris can achieve long distance dispersal and specific haplotypes were successful in colonizing habitats from the Xisha to the Nansha area. A total of 36 haplotypes were defined from 85 individuals with most of these haplotypes occurring only once. The dominant haplotype was found in twelve sampling sites. The largest distance between two sampling sites harbouring this haplotype is more than 700 km. Our findings of long distance dispersal in the South China Sea combined with mild genetic differentiation among fifteen sampling sites (average ΦST = 0.167) are in line with a scenario where population genetic structure is strongly impacted by colonization patterns. The seascape genetic structure of P.spinirostris in the South China Sea reflects both the importance of long distance dispersal as well as of reduced levels of gene flow, likely caused by colonization events followed by demographic expansions.
Chavtur, Vladimir Grygorjevich (2003): Morphology and distribution of some new pelagic ostracods of genus Metaconchoecia (Halocyprida: Halocyprididae) from the North Pacific. Zootaxa 229: 1-102, DOI: 10.5281/zenodo.156688
A new tribe of pelagic Ostracoda (Halocyprididae), the Metaconchoeciini, is established to encompass all the species formerly classified in the genus Metaconchoecia. All the remaining genera in the subfamily Conchoecinae are, therefore, assigned to another new tribe, the Conchoeciini. The original genus Metaconchoecia is subdivided into ten genera. Metaconchoecia is retained and nine new genera established namely: Austrinoecia, Clausoecia, Deeveyoecia, Juryoecia, Kyrtoecia, Muelleroecia, Nasoecia, Rotundoecia and Vityazoecia. Keys to these new genera and their component species are provided. Tables summarize the characters that most readily distinguish between the most closely related taxa. Appendices summarize the taxonomic characters and detailed size data for the majority of species that occur in the Atlantic and the North Pacific. A new species, Vityazoecia distoglandula, is described, which is designated as the type species of its genus.