Proposal of Arktourella gen. nov., a new genus of the family Normanellidae Lang 1944 (Copepoda: Harpacticoida) from the Province of Cortez

A new genus, Arktourella gen. nov., is proposed to accommodate a new member of the harpacticoid family Normanellidae, A. margarethae gen. et sp. nov., from a polluted estuary in north-western Mexico. The new genus was attributed to the laophontoidean family Normanellidae on account of the lack of outer spinous processes on the second antennulary segment, one abexopodal seta on the antennary allobasis, four setae on the one-segmented antennary exopod, endopod of first swimming leg two-segmented with first segment elongated and with two distal elements on second segment, endopods of second to fourth legs two-segmented, distal setae on the male second endopodal segment of second and third legs reduced, and outer spine of the male second endopodal segment of third leg fused to segment. The new, so far monotypic genus, differs from the other normanellid genera in the presence of four elements on the third exopodal segment of the first leg, and two outer spines on the third exopodal segment of second to fourth legs. No synapomorphies were observed for Arktourella gen. nov. and Normanella, but they are unique within the Normanellidae in that the mandibular basis and endopod are not fused. Maximum parsimony analysis and Bayesian inference using 59 morphological characters to assess the relationships between the genera of the family Normanellidae confirmed the affinity of Arktourella gen. nov. and Normanella, and their sister group relationship with Sagamiella. Paranaiara and Pseudocletodes were shown consistently to be closely related and are the sister taxa of Normanella-Arktourella gen. nov.-Sagamiella. Arktourella gen. nov., Paranaiara and Pseudocletodes share the presence of a large spinulose spine on the fifth and sixth segments of the female antennule, but its significance is not clear. Additionally, we propose a key to the genera of the Normanellidae.

Two new marine cyclopinids (Crustacea: Copepoda: Cyclopoida) from interstitial habitats in Korea

Marine cyclopoids, and especially cyclopinids, are poorly studied because their diversity is highest in marginal habitats, such as intertidal interstitial and anchialine caves, or in highly inaccessible abyssal and hadal depths. Two new cyclopinids are described here, both from two different sandy beaches in Korea. Among four species currently recognized in the genus, Heterocyclopina koreaensis sp. nov. is most closely related to H. vietnamensis Pleşa, 1969 from similar habitats in Vietnam. Koreacyclopina wellsi gen. et sp. nov. shares its sexually dimorphic third exopodal segment of the second leg with the Antarctic genus Pseudocyclopina Lang, 1946, but differs from all six known species by numerous features, some of which are observed for the first time within cyclopinids. Both Korean species belong to the family Hemicyclopinidae, but the monophyly of this group has not yet been demonstrated.

Proposal of two new genera of the family Zosimeidae Seifried (Copepoda: Harpacticoida): Heterozosime gen. nov. and Acritozosime gen. nov.

In the Pacific Ocean, the taxonomy of the family Zosimeidae Seifried, 2003 is poorly understood and to date only five species of the genus Zosime Boeck, 1873 are known. During oceanographic cruises exploring the species diversity of harpacticoids, two undescribed zosimeid copepods were sampled from shallow Korean waters and the deep northwestern Pacific. A detailed morphological examination has led us to propose two new genera, Heterozosime gen. nov. for the Korean zosimeid H. tenuis gen. et sp. nov. and Acritozosime gen. nov. for the deep-sea zosimeid A. spinesco gen. et sp. nov. Both new genera exhibit a distinctive feature in that the first thoracic leg has a two-segmented exopod, in contrast to the three-segmented exopod of this leg in all known zosimeid genera. Furthermore, Acritozosime gen. nov. can also be discriminated from other genera by the two-segmented endopod in second to fourth thoracic legs and the reduced setal armatures of the second exopodal segment of antenna, the first endopodal segment of first to third thoracic legs and the third exopodal segment in second to fourth thoracic legs. A comparison of the fundamental structures of appendages suggests that A. spinesco gen. et sp. nov. experienced a unique evolutionary history within the Zosimeidae.

A new species of Psammonitocrella Huys, 2009 (Copepoda, Harpacticoida, Ameiridae) from California (USA), with a discussion of the relationship between Psammonitocrella and Parastenocarididae

The freshwater harpacticoid Psammonitocrella kumeyaayisp. nov. from the Nearctic Region (California; USA) is proposed. The position of the genus within Harpacticoida and its relationship with the Parastenocarididae is discussed. The new species can be included within Psammonitocrella on account of a) the cylindrical furca, longer than the telson, b) the unmodified inner spine on the basis of the male first leg, c) loss of the outer spine on the second exopodal segment of the first leg, d) loss of the outer spine of the third exopodal segment of the second, third, and fourth legs, e) loss of the inner apical seta on the third exopodal segment of the second and third legs, f) transformation of the inner apical seta of the third exopodal segment of the fourth leg into a spine, and g) loss of the endopodite of the fourth leg. The new species differs remarkably from P. boultoni, and P. longifurcata in the loss of the outer spine of the second exopodal segment of the fourth leg, in the presence of a one-segmented fifth leg exopodite, and in the presence of an outer seta on the basis of the first and second legs. Both Psammonitocrella and the known species of Parastenocarididae have a one-segmented endopod on the fourth leg, and the endopods of the second and third legs are reduced to one or two segments. Psammonitocrella is currently allocated into the Ameiridae, and evidence suggesting a sister-group relationship with Parastenocarididae—both share the loss of the inner seta on the first endopodal segment of the first leg—indicates that the Parastenocarididae should be included into the Ameiridae. In an evolutionary context, Parastenocarididae could have evolved from a lineage of freshwater ameirids that became interstitial in continental waters and colonized aquifers and groundwaters.

A new genus and species of Nannopodidae (Crustacea, Copepoda, Harpacticoida) from the Yellow Sea of South Korea

A new monospecific genus of the family Nannopodidae Brady, 1880 is proposed, based on specimens of both sexes of Concilicoxa hispidagen. et sp. nov. collected from subtidal sandy sediments in the Yellow Sea of South Korea. The presence of a coxal outer projection on the first to fourth legs and reduction of both rami of the second to fourth legs in this new genus show a clear relationship with a clade, which is characterised by the modified thoracopods for burrowing ability, comprising Huntemannia Poppe, 1884, Rosacletodes Wells, 1985, Laophontisochra George, 2002, Acuticoxa Huys & Kihara, 2010 and Talpacoxa Corgosinho, 2012 in Nannopodidae. Within this clade, C. hispidagen. et sp. nov. is most closely related to L. maryamae George, 2002 in having the prehensile endopod in the first leg, broad intercoxal sclerite on the second to fourth legs and the female fifth leg being composed of separate exopod and baseoendopod, but is distinguished by the absence of mandibular exopod, two-segmented mandibular endopod, presence of four setae on the distal exopodal segment of the first leg, and fusion of the intercoxal sclerite to the coxae in the third and fourth legs. These four features are considered as autapomorphies of the new genus. The possible relationship amongst members of the nannopodid clade is further discussed. Additionally, some comments on the taxonomic position of L. terueae Björnberg, 2014 are given, resulting in the transfer of the species to Acuticoxa as A. terueaecomb. nov.

Two new species of Cryptopontius Giesbrecht, 1899 (Copepoda, Siphonostomatoida, Artotrogidae) associated with invertebrates from Northeastern Brazil

Cryptopontius is the most species-rich genus in the family Artotrogidae with 25 species, being recorded in almost all oceans, except in the Arctic. However only three species of this genus have been recorded from the Brazilian coast, all of them along the coast of Pernambuco state. This study describes two new species of the genus. Cryptopontius phyllogorgius sp. nov. differs from other species by having 9-segmented antennule, and nine elements on the third exopodal segment of leg 4. Cryptopontius pentadikos sp. nov. differs from its congeners by having five expressed antennulary segments proximal to fused ancestral IX-XII, two setae on second endopodal segment of leg 1, eight elements on third exopodal segment of leg 1 and the free segment of leg 5 with two setae. A key to species of the genus Cryptopontius is provided.

Pseudodiaptomus japonicus Kikuchi, 1928 (Copepoda, Pseudodiaptomidae), a brackish-water copepod formerly known as P. inopinus Burckhardt, 1913, on Sakhalin Island (Russian Far East)

We determined the taxonomic status of Pseudodiaptomus inopinus on Sakhalin using specimens from different localities, because it is currently known as a complex of species. The specimens examined appeared to belong to P. japonicus, based on the structure of the female genital operculum. However, a few females lacked spinules on the medial surface of the first exopodal segment of the female P5, which has been described as a character distinguishing P. japonicus from its two sibling species. The species is distributed in brackish waters from the very south to the very north of Sakhalin Island. The northernmost locality on Sakhalin is also the northernmost record of the species.

A new species of Boholina (Crustacea, Copepoda, Calanoida) and a first record for stygobiotic calanoid fauna from a cave in Thailand

A new species of Calanoida belonging to the genus Boholina Fosshagen & Iliffe, 1989 was found in a freshwater pool within a cave of the Satun province, South Thailand. It is the first record of the genus and of a stygobiotic representative of calanoid fauna in this country. The new species is most similar to B. crassicephala Fosshagen & Iliffe, 1989, based on position of genital pores, structures of P4 and P5 in both sexes, relative length of subapical spine vestige on the male right P5, and shape of the male left P5 endopods. However, this new species is distinguished from its known congeners by: (1) relatively longer distal outer spines on the male right P5 exopods, (2) smaller endopods of the male left P5 and (3) elongated apical spines on the distal exopodal segment of the female P4 and P5. Furthermore, the distinctive characteristic of the Thai Boholina is the presence of inner minute seta on the distal segment of the male right P5 exopod. Detailed descriptions of the new species and a key to all six known species of the genus Boholina is provided.

A new species of Bestiolina (Crustacea, Copepoda, Calanoida, Paracalanidae) from coastal waters of the Colombian Pacific, including a worldwide key for the identification of the species

Plankton samples obtained from estuarine waters of the Colombian Pacific yielded adults specimens of an undescribed species of a paracalanid copepod of the genus Bestiolina. It most closely resembles two Asian species; B.sinica (Shen & Lee, 1966) from China and B.arabica (Ali, Al-Yamani & Prusova, 2007) from the Arabian Gulf. These three species share the absence of spinules on the posterior surfaces of exopod segments of legs 2, 3 and 4. Bestiolinasarae Dorado-Roncancio & Gaviria, sp. n. can be easily separated from B.sinica by the number of spinules on the anterior surface of endopod 2 of legs 2 and 3, and by the absence of spinules on the posterior surface of second endopod of leg 4. It can be distinguished from B.arabica by the presence of spinules on the posterior surface of endopod 2 of same legs (absent in B.arabica), and the size of spinules on the anterior surface of the same segments. The only other species known from the Americas, B.mexicana (Suárez-Morales & Almeyda-Artigas, 2016), can be distinguished from Bestiolinasarae Dorado-Roncancio & Gaviria, sp. n. by the presence of spinules on the posterior surface of the leg 2 first exopodal segment and the morphology of the mandible blade. The morphological and meristic differences to the eight known species of the genus are presented. An identification key to the species of Bestiolina is provided.

New species of Eurycletodes Sars, 1909 and Odiliacletodes Soyer, 1964 from the deep Gulf of California (Copepoda, Harpacticoida, Argestidae)

To date, three species of the family Ancorabolidae, three species of the family Argestidae, and one species of the family Rhizothrichidae are known from the deep sea of the Gulf of California. The descriptions of two new species,Eurycletodesparaephippigersp. n.andOdiliacletodessecundussp. n.collected from the Southern Trough of Guaymas Basin at 1440 m and 1642 m depths, respectively, are presented herein. The closest relatives of these two species,E.ephippigerPor, 1964 andO.gracilisSoyer, 1964 are known from the Mediterranean, but some relatives have been reported also from the southern Atlantic.Eurycletodesparaephippigersp. n.is undoubtedly related toE.ephippigerPor, 1964 known from Israel and Banyuls-sur-Mer (France). These two species can be separated by the armature complement of the basis of the maxillule, by the armature complement of the syncoxa of the maxilliped, and by the relative position of the anal operculum.Odiliacletodessecundussp. n.showed to be closely related toO.gracilisSoyer, 1964 known from Banyuls-sur-Mer only. The latter two species can be separated by the armature complement of the syncoxa of the maxilliped, by the structure of the antenna, and by the inner armature complement of the third exopodal segment of the fourth swimming leg.