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.

A new species of Paralaophonte Lang 1948 (Harpacticoida: Laophontidae), with notes on the phylogeny of the genus and its relationships with Loureirophonte Jakobi 1953 using Bayesian inference

Early studies during the 1990’s supported a close relationship between the genera Paralaophonte and Loureirophonte. Subsequent studies carried out during the first decade of the 2000’s suggested the monophyly of the latter and that it could be nested within Paralaophonte, rendering the latter paraphyletic. However, efforts to synonymize these two genera were hampered by the lack of phylogenetic analyses at the species level. Here we describe a new species of Paralaophonte from north-western Mexico, P. ullama sp. nov., and we formally synonymize Loureirophonte with Paralaophonte for which we propose two monophyletic subgenera, Pa. (Paralaophonte) and Pa. (Loureirophonte). The detection of the species most closely related to P. ullama sp. nov. is controversial. Our Bayesian analysis indicates that the new species might be related to Pa. (Pa.) gurneyi, and to Pa. (Pa.) ormieresi and Pa. (Pa.) septemarticulata, with which they form a larger clade supported by a very low Bayesian Posterior Probability value. However, the precise nature of the relationship between the new species and Pa. (Pa.) gurneyi is hampered by the gap in our knowledge of the armature formulae of the swimming legs of the latter, and by the lack of the male of the new species. On the other hand, the new species share several characters with Pa. (Pa.) problematica, Pa. (Pa.) pacificavicinum, Pa. (Pa.) pacificaemulator, and Pa. (Pa.) pacifica, with which it might be related. Our Bayesian analysis of forty-two morphological characters at the species level confirmed earlier suspicions about the relationships between Paralaophonte and Loureirophonte, the latter being nested within the former, and showed the monophyly of the Paralaophonte-Loureirophonte clade with high Bayesian Posterior Probability value, thus confirming the synonymy of these genera. The Paralaophonte-Loureirophonte clade is defined by the synapomorphic dimorphism in the second endopodal segment of the second swimming leg of the male. We did not detect any (aut)apomorphy for Pa. (Paralaophonte). Paralaophonte (Loureirophonte) is defined by the presence of one seta only on the second endopodal segment of the second swimming leg, and the one-segmented endopod of the fourth swimming leg.

A new species of Stygiopontius (Copepoda, Siphonostomatoida, Dirivultidae) from a deep-sea cold seep in the South China Sea

A new species of the copepod genus Stygiopontius is described based on samples from a cold seep in northeastern South China Sea southwest to Taiwan, which were collected by the ROV Faxian with its mother vessel R/V Kexue in September 2017. The copepods were obtained by washing Shinkaia crosnieri Baba & Williams, 1998 (Decapoda: Munidopsidae) caught at a depth of 1124 m. The new species can be distinguished from its congeners by the combination of the following characteristics: caudal rami about 3.5 times as long as wide; basis of maxilliped with plumose seta, endopodal claw of maxilliped stout, with a row of fine spinules on inner margin; coxa of leg 1 with one inner seta; basis of leg 1 with stout spine exceeding to end of first endopodal segment; second endopodal segment of female leg 4 with pointed process; third exopodal segment of leg 4 with three outer spines. This is the first record of a Stygiopontius species from a cold seep.

A new species of parasitic copepod (Siphonostomatoida: Lernaeopodidae: Neoalbionella Özdikmen, 2008) infecting the skin of a gulper shark, Centrophorus sp. (Squaliformes: Centrophoridae), in the Gulf of Mexico, with a key to species of Neoalbionella

We describe male and female specimens of a species of NeoalbionellaÖzdikmen, 2008 (Siphonostomatoida, Lernaeopodidae), Neoalbionella dannytangisp. nov., infecting the skin of a gulper shark Centrophorus sp. (Centrophoridae) in the northern Gulf of Mexico. Females of the new species most closely resemble those of Neoalbionella globosa (Leigh-Sharpe, 1918) but are unique among congeners by having the combination of 1) terminal endopodal segment of antenna with a reduced distal tubercle having a minute protuberance, 2) maxillule with a spinulose lateral palp and praecoxal endite, 3) maxilla with a swollen tip nearly parallel with the distal surface of the bulla, and 4) maxilliped with a sub-circular spinulose pad along the proximal myxal margin of the corpus maxillipedis. The male copepod was attached to the tip of a female’s posterior process and was assigned to Neoalbionella by having a cephalosome nearly equal in length to the trunk and tapered caudal rami directed posteroventrally (swollen and directed anterodorsally in males of Lernaeopoda von Nordmann, 1832). It was distinct from those of all other congeners by having 1) an antenna terminal endopodal segment and maxillule similar to that of the female, 2) a maxilla syncoxa with an anteromedial process having seven large, conical denticles, 4) a bifid mediative process approximately as wide as the length of the shortest lobe, and 5) a caudal ramus with a unique configuration and number of setae. This is the second report of a species of Neoalbionella from the Gulf of Mexico and the third nominal species of Neoalbionella reported from gulper sharks (Centrophorus spp.). We also provide keys to females and males of Neoalbionella.

A new Setacheres (Copepoda, Siphonostomatoida, Asterocheridae) associated with Ircinia felix (Duchassaing & Michelotti) (Porifera) from Brazil

Recent surveys of the copepod fauna associated with the sponge Ircinia felix (Porifera, Dictyoceratida) in Brazil resulted in the discovery of a new siphonostomatoid species belonging to a recently erected genus of Asterocheridae. Setacheres portobarrensis sp. nov. possesses a 21-segmented antennule, with 3 free distal segments, after the aesthetasc. The third exopodal segment of leg 3 shows a distal seta instead of a spine as in some other congeners. The new species shows several unique features on the third endopodal segment of the antenna, the mandibular stylet, the inner lobe of the maxillule, and setules and spinules located in specific regions of legs 1 to 4. Setacheres portobarrensis sp. nov. follows the same distributional pattern as its congeners, and this is the first record of a siphonostomatoid copepod associated with Ircinia felix.

First record of the genus Nitocrella Chappuis, 1923 (Copepoda, Harpacticoida, Ameiridae) from India, with a new phreatic species

Nitocrella galassiaen. sp. is described from phreatic waters in Andhra Pradesh state located in southeastern peninsular India. This is the first representative of the genusNitocrellaChappuis, 1923, described from the Indian subcontinent. Following Petkovski’s (1976) revision of the genusNitocrellas. str., the new species is assigned to thechappuisi-group of species. It differs from all other members of this group by a unique combination of the following characters: the male leg 1 basis has a short claw-like inner spine; the second exopodal segment of legs 1-4 has an inner seta; the apical endopodal segment of legs 2 and 4 has a single seta; leg 5 exopod in both sexes has three setae, and the baseoendopodal lobe has three setae in the female and two setae in the male; the male fifth antennular segment has a large aesthetasc; and the caudal ramus is 1.5 times as long as its greatest width and about 0.7 times as long as the anal somite. Among the hitherto known species of thechappuisi-group, the new species shows an allegedly close relationship with the IranianN. petkovskiiPesce, 1980. A brief note on the ecology of the new species is also added.

Two hyporheic species of the genus Cerconeotes Huys, 1992: C. euryhalinus (Krishnaswamy, 1957) and C. huysi n. sp. (Copepoda, Harpacticoida, Leptastacidae) from India

To date, the genus Cerconeotes Huys, 1992, has seven nominal species, all known mostly from marine interstitial waters. Here, Cerconeotes euryhalinus (Krishnaswamy, 1957), an incompletely described and little-known species, is redescribed in detail after designating the neotype, and an illustrated description is given for Cerconeotes huysi n. sp. Both species were collected from freshwater as well as brackish water hyporheic habitats in southeastern India. The morphological relationships of these species with their congeners are discussed, and two criteria of the original generic definition emended. Cerconeotes huysi n. sp. is unique in the genus in the shape and armature of leg 5 in both sexes, in the male leg 3 second endopodal segment with two smooth, spine-like reduced elements (one apical and one subapical), and the long caudal rami and their armature elements. It closely resembles C. euryhalinus. A brief note on the ecology of the species is also added.

Atopobathynella paraoperculata n. sp. (Syncarida, Bathynellacea, Parabathynellidae) from the River Krishna, southeastern India

To date, the genusAtopobathynellaSchminke, 1973, is known by 11 species in the world. Here,Atopobathynella paraoperculatan. sp., the second species of this genus from India, is described from the interstitial hyporheic zone of the River Krishna in Andhra Pradesh state. It has closest similarity with its Indian congener,AtopobathynellaoperculataRanga Reddy, Drewes & Schminke, 2008, as borne out by the fusion of the inner flagellum of the antennule with the first segment of the outer flagellum, the presence of a seta on the subdistal outer surface of the uropodal sympod; the antennal organ consists exclusively of two massive lobes; the antenna has three instead of four armature elements; the proximal segment of the maxillule has two instead of four distinct claws; the uropodal sympod has an inhomonomous row of spines; and the anal operculum is massive. However, the new species can be easily separated fromA. operculataby several other criteria such as the labrum without vs. with tubular pores; the second endopodal segment of Th I has two setae vs. one seta; the uropodal sympod has four vs. eight spines; the uropodal endopod has two weak setae vs. one normal seta; the pleotelson is unarmed vs. armed; and the anal operculum has a subacute vs. a rounded tip. Further, based on the novelties observed in the two Indian congeners, some of the principal generic characters and their states are briefly discussed, and also some ecological notes are added.

Variation of Von Vaupel Klein’s organ among genera of the Calanidae and Megacalanidae (Copepoda, Calanoida)

Von Vaupel Klein’s organ (VVKO), an association of the basal seta and proximal segment on the endopod of swimming leg 1 on many gymnoplean copepods, is surveyed on one species each of eight genera of calanids, viz., Calanoides acutus Giesbrecht, 1902, Calanus finmarchicus (Gunnerus, 1770), Canthocalanus pauper (Giesbrecht, 1888), Cosmocalanus caroli (Giesbrecht, 1888), Mesocalanus lighti (Bowman, 1955), Nannocalanus minor (Claus, 1863), Neocalanus robustior (Giesbrecht, 1888) and Undinula vulgaris (Dana, 1849), and three of megacalanids, viz., Bathycalanus richardi Sars, 1905, Bradycalanus typicus Sewell, 1947 and Megacalanus longicornis Sars, 1905. In this exploratory survey, VVKO shows significant variability among the eleven species in the shape of the distodorsal corner of the proximal endopodal segment, presence and location of denticles on the anterior face of the segment, presence and size of denticles along the distal margin of the segment, number of pores on the segment, shape of the seta that originates on the basis, and the nature of the basis at the origin of the seta.

A new species of Boholina (Copepoda, Calanoida, Boholinidae) from Ganghwa Island in western Korea

A new species of Boholina, B. ganghwaensis sp. nov. is described, based on specimens collected from burrows of the manicure crab, Cleistostoma dilatatum, in the tidal flat of Ganghwa Island in western Korea. The new species is closely similar to B. purgata and B. parapurgata by having a pointed process on the posterior angles of the second and third pedigerous somites and a similar rostrum in the female, but can be distinguished from its congeners by the following characters: in females by the genital double-somite with small hook-like process on each gonoporal plate, the setation of the distal endopodal segment of mandible, the basis and first endopodal segment of the maxillule incompletely separated, the inner distal spine/outer terminal spine length ratio on P5; and in males by the distal spine present on the posterior surface of the basis of both P5 and the length/width ratio of the endopod of the right P5. This is the first Bololina species recorded from the north-west Pacific.