Planktonic ostracods (Myodocopa: Halocyprididae) from abyssopelagic depths in the Atlantic, North Pacific and Gulf of Oman: Chavturia abyssopelagica (n. gen., n. sp.), Halocypretta profunda (n. sp.), Halocypretta parvirostrata Chavtur and Stovbun, 2008 and Halocypretta striata (Müller, 1906).

A novel species and genus of halocyprid ostracod, Chavturia abyssopelagica, and a new species of Halocypretta are described from depths > 3000 m in the Atlantic. The new genus is related to Halocypretta, itself a genus that has only recently been described from deep waters in the North Pacific. Supplementary observations are made on the type species, Halocypretta parvirostrata, based on additional specimens from the North Pacific. Halocypretta striata from the Gulf of Oman is reported for the first time since it was first described and is redescribed in detail. All four species are illustrated and compared using a set of meristic characters.

Description of two new Proceroecia species (Ostracoda: Halocyprididae) from neritic waters off South Korea with an insight into the morphological and molecular diversity of the genus.

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.

Septemoecia a new genus of halocyprid ostracod (Myodocopa, Halocyprididae, Bathyconchoeciinae) for the seven-spined species formerly attributed to Bathyconchoecia.

The five species with seven large carapace spines that were previously assigned to the genus Bathyconchoecia are re-classified in a new genus Septemoecia. Septemoecia longispinata (Ellis, 1987) (new combination) is designated as the type species. The previously unknown adult female of S. georgei (Kornicker Rudjakov, 2004) (new combination) and adults of S. septemspinosa (Angel, 1970) (new combination) are described. Meristic and zoogeographical data are presented and a key to the species based on external carapace characters is provided.

Identification, Discrimination, and Discovery of Species of Marine Planktonic Ostracods Using DNA Barcodes.

The Ostracoda (Crustacea; Class Ostracoda) is a diverse, frequently abundant, and ecologically important component of the marine zooplankton assemblage. There are more than 200 described species of marine planktonic ostracods, many of which (especially conspecific species) can be identified only by microscopic examination and dissection of fragile morphological characters. Given the complexity of species identification and increasing lack of expert taxonomists, DNA barcodes (short DNA sequences for species discrimination and identification) are particularly useful and necessary. Results are reported from analysis of 210 specimens of 78 species of marine planktonic ostracods, including two novel species, and 51 species for which barcodes have not been previously published. Specimens were collected during 2006 to 2008 from the Atlantic, Indian, and Southern Oceans, Greenland Sea and Gulf of Alaska. Samples were collected from surface to 5,000 m using various collection devices. DNA sequence variation was analyzed for a 598 base-pair region of the mitochondrial cytochrome oxidase subunit I (COI) gene. Kimura-2-Parameter (K2P) genetic distances within described species (mean = 0.010 ± 0.017 SD) were significantly smaller than between species (0.260 + 0.080), excluding eight taxa hypothesized to comprise cryptic species due to morphological variation (especially different size forms) and/or collection from different geographic regions. These taxa showed similar K2P distance values within (0.014 + 0.026) and between (0.221 ± 0.068) species. All K2P distances > 0.1 resulted from comparisons between identified or cryptic species, with no overlap between intra- and interspecific genetic distances. A Neighbor Joining tree resolved nearly all described species analyzed, with multiple sequences forming monophyletic clusters with high bootstrap values (typically 99%). Based on taxonomically and geographically extensive sampling and analysis (albeit with small sample sizes), the COI barcode region was shown to be a valuable character for discrimination, recognition, identification, and discovery of species of marine planktonic ostracods.

A re-description of Discoconchoecia elegans (Sars, 1865) (Ostracoda: Halocyprididae) from high latitudes in the North Atlantic.

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 magnitude of global marine species diversity.

BACKGROUND: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. RESULTS: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000-72,000 species are collected but not yet described, and that 482,000-741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7-1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. CONCLUSIONS: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century.