Description and female genital structures of a new species of the demersal calanoid copepod Ridgewayia from southern Japan

A new species of the demersal calanoid copepod Ridgewayia, R. boxshalli n.sp., is described from southern Japan. This is the first record of the genus in Japan. It is distinguishable from other congeners by the antennule and leg 5 of both sexes. In order to identify evolutionary trends, detailed observations were also carried out on the female genital structures using light and scanning electron microscopy for comparison with other calanoids. Their organization is characterized by two egg-laying ducts opening through paired gonopores into a small cavity, the genital atrium, covered by a genital operculum and opening to the outside through a distal atrial slit. No seminal receptacle is present. The unique morphological features and in situ feeding habit of Ridgewayia are also noted.     

Systematics and zoogeography of the deep‐sea hyperbenthic family Arietellidae (Copepoda: Calanoida) collected from the Sulu Sea

A faunistic survey of the deep‐sea hyperbenthic copepods in the Sulu Sea, which has a deep basin and is connected via shallow straits with the Pacific and the South China Sea, was carried out in November and December 2002, using beam trawls and a mid‐water trawl. Two new genera and four new species of the primitive calanoid family Arietellidae are described. A new genus Metacalanalis shows intermediate characteristics between those of Metacalanus Cleve, 1901 and Pilarella Alvarez, . Another new genus, Protoparamisophria, is closely related to Paramisophria Scott, 1897, but exhibits more plesiomorphic states in the female genital system and appendages. Two new species of the genera Paraugaptiloides Ohtsuka, Boxshall and Roe, and Sarsarietellus Campaner, 1984 are the second and the third species, respectively, for these genera. This discovery enhances the validity of these rare genera, and sheds light on the geological history of the Sulu Sea and the evolution of the Arietellidae within it.     

A new Arietellidae (Copepoda: Calanoida) from the Red Sea

A new species of the calanoid copepod genus Paramisophria T. Scott, 1897 is described from the Egyptian sublittoral zone of the Red Sea. Paramisophria aegypti sp. nov. appears to be closely related to the species Paramisophria ammophila and Paramisophria platysoma. Paramisophria aegypti differs from P. ammophila in having two unequal lateral setae plus one long terminal process and two tiny equal lateral setae plus one long terminal process on the third exopodal segment on the male right and left fifth legs (vs three terminal processes increasing in size inward on both male fifth legs). Paramisophria aegypti can be distinguished from P. platysoma in the following characters: prosome symmetrical (vs extreme asymmetry); third exopod segment of the right leg completely separated from the second segment and bears two unequal lateral setae plus one long terminal process (vs partially fused to the second segment and bears four terminal processes increasing in size inward); third exopod segment of the left leg with two lateral setules and one long terminal process (vs two lateral setules, one short outer medial process and one long terminal process); endopodal lobes of the female legs 5 bear one long plumose seta (vs setae are lacking).http://www.zoobank.org/urn:lsid:zoobank.org:pub:C0A92BF9-2306-4A35-AA39-CE3B5865A396     

Intraspecific variation in integumental pore signatures in the genus Pleuromamma (Copepoda: Calanoida)

Intraspecific variation in the pore signature of calanoid copepods is evident between individuals within a single geographical area (within-sample variation) and between different geographical area (geographical variation). Previous studies, however, have tended to consider only geographical variation, neglecting within-sample variation; thus the question remains on how representative the data are of biogeographic divergence within a species. Eight species of the metridinid genus Pleuromamma are examined and the extent of intraspecific variation in pore signatures is assessed here in terms of within-sample variation. In general, the degree of intraspecific variation increases with increasing number of the total integumental pores and is limited to 10% or less of the total. Intraspecific variation reflects not only genetic variability within a species but also genetic similarities between the species within a genus. This paper also re-examines published data on intraspecific variation in pore signatures. Samples as small as five individuals will identify >95% of potential sites of pores.     

New species of Lucicutia and taxonomic status of L. grandis (Copepoda,Calanoida, Lucicutiidae)

Calanoid copepod specimens attributable to Lucicutia grandis (Giesbrecht, ), L. bradyana Cleve, , L. wolfendeni Sewell, , and L. rara Hulsemann, ) were studied from antarctic and subantarctic waters collected during RV Eltanin crusies 4–11 and 23, and RV Ob cruises 1 and 3. In addition, identified specimens from the Pacific and Indian Oceans deposited in the systematic collections of the National Museum of Natural History, Smithsonian Institution (Washington, DC, USA) and the Zoological Institute, Russian Academy of Sciences (St Petersburg) were also examined. Both sexes of a new species are described from the eastern tropical Pacific Ocean, L. hulsemannae. Lucicutia hulsemannae is distinguished from L. grandis, L. bradyana and L. wolfendeni by the morphology of the rostrum, genital complex, including plug, and leg 5 of both sexes. Lucicutia bradyana is not found outside the Southern Hemisphere but L. grandis is recorded from the Arabian Sea, the Bay of Bengal, tropical Indian Ocean, as well as its type locality in the eastern tropical Pacific Ocean. Lucicutia wolfendeni is found in all oceans except the Arctic Ocean. The status of L. bradyana, previously rejected as a separate species by Hulsemann (), is restored. Lucitutia rara is considered a junior synonym of L. bradyana.     

New species of Brodskius,Rythabis, and Omorius (Crustacea: Calanoida) from deep Antarctic waters

Three new species of rare benthopelagic clausocalanoidean genera with sensory setae on the maxilla are described from female specimens collected during the German Antarctic expeditions ANDEEP I–III in 2002 and 2005, mainly from abyssal depths close to the sea bed. Brodskius abyssalis sp. nov. differs from congeners by the lack of rostral filaments, two setae on the second segment of antenna exopod, thread‐like tips of maxillary worm‐like sensory setae, and the length of spines of P5 exopod. Rythabis assymmetrica sp. nov. is distinguished from other species in the genus by asymmetrical posterior corners of the prosome, the shape of spermathecae, and setal numbers on the maxillulary distal basal endite plus endopod. Omorius curvispinus sp. nov. is characterized by strongly curved setae of the maxillipedal syncoxa, a comparatively long seta on the basis of antenna, a slightly swollen genital double‐somite, and the shape of spermathecae. The genera Brodskius, Omorius, and Rythabis are recorded for the first time from the southern hemisphere.     

New family and genus Rostrocalanus gen. nov. (Crustacea: Calanoida: Rostrocalanidae fam. nov.) from deep Atlantic waters

Two new species of a new genus and family Rostrocalanidae of benthopelagic clausocalanoid copepods are described from female specimens collected from abyssal depths close to the sea bed in the tropical Atlantic. Rostrocalanus gen. nov. shares the presence of sensory setae on maxilla with other bradfordian families of Clausocalanoidea, but does not fit the diagnosis of any of these families. A family Rostrocalanidae is established for this new genus and is defined by the following derived characters: four‐segmented exopod of mandible supplied with four setae; distal basal endite of maxillule fused to endopod and bearing five setae in total; endopod of maxilla furnished with six worm‐like sensory setae; arrangement of setal numbers on praecoxal endites of maxilliped syncoxa as 0, 1, 2. The establishment of a new clausocalanoidean family sheds new light on the morphological diversity of bradfordian benthopelagic copepods and adds to the biodiversity of the deep‐water calanoid fauna.     

A new deep-water calanoid copepod and the phylogeny of the genus Nullosetigera nom. nov. in the Nullosetigeridae nom. nov. (pro Phyllopus: Phyllopodidae) from Japanese waters

Nullosetigeridae nom. nov. is proposed for Phyllopodidae Brodsky, 1950, nom. nud., and Nullosetigera nom. nov. is introduced for Phyllopus Brady, 1883, non Rafinesque, 1815. A new species, Nullosetigera auctiseta, is described from Japanese waters. Nullosetigera mutica comb. nov. (Sars, 1907) and N. mutata comb. nov. (Tanaka, 1964) are redescribed. Phylogenetic analysis implies that two groups, N. auctiseta–N. mutica group and N. mutata–N. impar–N. bidentata–N. helgae group, exist within the genus Nullosetigera and that the new species first diverges with N. mutica. The relatively advanced species, N. impar, N. bidentata, and N. helgae are the most widespread, and are vertically distributed from the epipelagic to the bathypelagic layers.