Tanaidacea (Crustacea: Peracarida) of the North-east Atlantic: the genera Leptognathioides and Portaratrum of the ‘Atlantic Margin’

The tanaidomorphan genera Leptognathioides and Portaratrum from the Benthic Invertebrates of Icelandic waters (BIOICE), Marine Benthic Fauna of the Faroe Islands (BIOFAR), and Atlantic Frontier Environmental Network (AFEN)-related surveys are examined. The diagnosis for Leptognathioides polita is amended and additional size data are given. A new species, L. biarticulata, is described although the differences from L. polita are slight. It occurs in the bathyal Iceland Basin with a distribution that does not overlap with that of L. polita. A new species of Portaratrum, P. holdichi, is described and the apparent similarities (parallelisms) between this former colletteid genus and the akanthophoreid Chauliopleona are discussed. The distribution and rarity of both genera in the region are analysed, Leptognathioides being more common in the cold-water areas or along the cold–warm interface. Portaratrum holdichi n. sp. is more common and abundant in the Rockall-Biscay region of the NE Atlantic.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:81262671-0665-49C3-9A02-F243C60FC334     

The Tanaidacea (Crustacea,Peracarida) of the North-East Atlantic: the shelf and bathyal Paratyphlotanais of the ‘Atlantic Margin’

Increasing oil-exploration activity and associated ecological surveying west of the Shetlands is leading to the discovery of many poorly known or undescribed tanaidaceans. Three species of the typhlotanaid genus Paratyphlotanais Kudinova-Pasternak and Pasternak, 1978 Kudinova-Pasternak R. K Pasternak F. A 1978 Deep sea Tanaidacea collected from the Caribbean Sea and Puerto Rico trench during the 16th cruise of RV ‘Akademik Kurchatov’ and the resemblance between the fauna of deep-sea Tanaidacea of the Caribbean region and the Pacific Trudy Instituta Okeanologiii. Akademiya Nauk SSSR, 113, 115–135 (in Russian)  [Google Scholar] have been recorded from shelf and bathyal depths between Iceland, the Faroe Islands and the western margin of the British Isles. Two, P. gracilipes (Hansen) and P. microcheles (G. O. Sars), formerly belonging to the genus Typhlotanais, are redescribed and a new species is described. A key to their identification is included. Inhabiting largely discrete zoogeographic areas, these species help define regional macrofaunal associations.     

Crab‐associated amphipods from the Falkland Islands (Crustacea,Peracarida)

Four species of associated amphipods were collected from the lithodid crab Paralomis granulosa in the Falkland Islands: Jassa kjetilanna n. sp. (Ischyroceridae), Gammaropsis monodi (Schellenberg, 1931 Schellenberg, A. 1931. Gammariden und Caprelliden des Magellangebietes, Südgeorgiens und der Westantarktis.. Further Zoological Results of the Swedish Antarctic Expedition 1901–1903, 2: 1–290.  [Google Scholar]) (Photidae), Aora karibu n. sp. (Aoridae), and Paramoera falklandica n. sp. (Eusiridae s.l.). The Gammaropsis was also found on the majid crab Eurypodius latreillei, where it seemed to be the only associate. A survey of all amphipod associations involving lithodid crabs is provided.     

Description of four new species of the Cirolana ‘parva group’ (Crustacea: Isopoda: Cirolanidae) from Thailand,with supporting molecular (COI) data

Four new species of the Cirolana ‘parva group’ from shallow coastal habitats in Thailand are described: Cirolana andamanensis sp. nov. and C. phangnga sp. nov., from the Andaman Sea, and C. siamensis sp. nov. and C. thailandica sp. nov. from the Gulf of Thailand. Molecular (The cytochrome oxidase subunit I gene) analysis incorporating taxa from the Cirolana ‘tuberculate group’ shows a monophyletic clade (Bayesian inference = 1 and maximum likelihood = 100%) within the Cirolana ‘parva group’ with two clades reflecting morphological characters. Cirolana andamanensis sp. nov. with antennula peduncle articles 1 and 2 entirely fused; male pereopod 1 without a setal fringe; uropod peduncle ventrolateral margin with 1 sensory seta. Cirolana phangnga sp. nov., C. siamensis sp. nov. and C. thailandica sp. nov. share the morphological characters of antennula peduncle articles 1 and 2 distinctly articulated; pereopod 1 in male with a setal fringe on the carpus and propodus; uropod peduncle ventrolateral margin with 3 sensory setae. Uncorrected p-distances strongly support the separation of these species, originally based on morphology, and show that the highest value of 32.1% is between C. thailandica sp. nov. and C. andamanensis sp. nov., while the lowest value of 22.5% is between C. phangnga sp. nov. and C. siamensis sp. nov.     

Stenothoidae (Crustacea: Amphipoda) of hydrothermal vents and surroundings on the Mid‐Atlantic Ridge,Azores Triple Junction zone

Four new species of Stenothoidae were collected from the Azores Triple Junction zone during different French cruises on the Mid‐Atlantic Ridge. One of the species belongs to the genus Torometopa (T. saldanhae) and is the first record of this genus in the Atlantic Ocean. The three other species belong to the genus Stenothoe (S. divae, S. marvela, and S. menezgweni). It is not possible to determine from morphological and ecological characters whether these amphipod species are endemic to hydrothermal systems or are bathyal species that may be found away from vent sites.     

Ephippia of Cladocera (Crustacea: Branchiopoda) from the Oligocene Tremembé palaeolake,Brazil

Ephippia of Cladocera (Crustacea: Branchiopoda) are found in the Oligocene deposits of Tremembé Formation (Taubaté Basin, Southeast Brazil). Thirty specimens from a short stratigraphic interval of a 115-m section of a core drilled in Taubaté city, São Paulo state, have been studied. Based on the morphology, we assumed that they might belong to two diferent species of Daphnia (Ctenodaphnia) which lived either in the Tremembé palaeolake or in some surrounding temporary waters. Our find represents the oldest record of fossil ephippia in South America and the second record of Daphnia (Ctenodaphnia) in the former Gondwana. A tentative palaeolimnological interpretation is proposed based on the ephippia occurrences, allied to ostracod and lithological data.     

A new genus and species of Heteromysini (Crustacea‐Mysidacea) from the backwater of Kochi (Kerala,India)

Kochimysis pillaii, a new genus and species of Heteromysini collected from the backwater of Kochi, is described. The new genus is closely related to the genus Deltamysis but is distinguishable from the latter by the following characters: antennules of male have a small setiferous lobe; antennal scale is without distal suture; second segment of mandibular palp broad; endopodite segments of maxilla subequal in length; in male carpus and propodus of second thoracic endopod with notches on outer margin; outer pair of apical spines on telson longer than the inner pair.     

On Paranacypris samambaiensis gen. nov., sp. nov. (Crustacea,Ostracoda), the first South American psychrodromid from the alluvial valley of the Upper Paraná River,Brazil

Paranacypris samambaiensis gen. nov., sp. nov. is here described from closed lakes in the alluvial valley of the Upper Paraná River. The new genus, characterized by a large frontally overlapping left valve, belongs in the Psychrodromini, and is the first representative of this tribe described in South America. Nevertheless, it has some different character states, and the diagnosis of the tribe had to be adapted. The species is rare and restricted to closed lakes (not in contact with the main channels of the river). It mostly occurs in benthic littoral habitats, and far less in the pleuston communities, the most common habitat in this floodplain. The behaviour of P. samambaiensis gen. nov., sp. nov. is enigmatic because it combines long natatory setae on the antennae (swimming behaviour) with a very stout caudal ramus, including the spine‐like posterior seta (crawling behaviour). We present a key to the genera of the Herpetocypridinae.     

Cienfuegia gen. nov. (Xyalidae) and Pseudoterschellingia gen. nov. (Linhomoeidae), two new genera of free‐living marine nematodes from the Caribbean Sea

Two new genera of nematodes are described from the Caribbean Sea. Cienfuegia gen. nov. belongs to the Xyalidae based on the position of the anterior gonad constantly left of the intestine, cuticle clearly striated, second and third circle of anterior sensilla inserted at the same level and buccal cavity surrounded by pharynx. The new genus is differentiated from other genera by the buccal cavity divided in two chambers and by the four cephalic setae being longer than the six outer labial setae. Within the Xyalidae, Cienfuegia shows most affinities with the genera Daptonema and Theristus. Pseudoterschellingia gen. nov. is placed within the Linhomoeidae on the basis of the presence of anterior rounded amphidial fovea, unarmed narrow buccal cavity, distinctive cardia and presence of apophysis of gubernaculum. Pseudoterschellingia is closely related to the genera Terschellingia and Terschellingioides, but is differentiated by the crypto‐spiral amphidial fovea, and conical buccal cavity surrounded by pharyngeal tissue.