On Liljeborgia fissicornis (M. Sars, 1858) and three related new species from Scandinavia,with a hypothesis on the origin of the group fissicornis

The large and common Scandinavian amphipod Liljeborgia fissicornis (M. Sars) is split into four species: the deep-water L. caliginis sp. nov. and L. charybdis sp. nov., and the shallow-water L. fissicornis and L. ossiani sp. nov. The poorly known species L. polosi Barnard and Karaman, recorded from the deep Canadian Basin of the Arctic Ocean, is considered as belonging to the same group. All those northern species are completely devoid of eyes, while similar species from the Antarctic and sub-Antarctic continental shelf do have eyes. It is hypothesized that the group fissicornis, which is specific to cold waters, derives from ancestors living on the continental shelf of the Southern Ocean. These ancestors would have adapted to deep-sea environments, losing their eyes completely. Then they would have migrated northwards through the cold abyss, and reached the cold but shallow waters of the Arctic/sub-Arctic continental shelf, without redeveloping visual organs.     

Arctic species of the cheilostome bryozoan Microporella,with a redescription of the type species

This investigation focuses on the diversity and taxonomy of species of Microporella found north of the Arctic Circle. Firstly, however, a neotype is chosen for the Mediterranean type species M. ciliata (Pallas) in order to stabilize the taxonomy of this “pseudocosmopolitan” species, which has been recorded in the past from the Arctic. Study of type and other material using scanning electron microscopy shows that only two Arctic species of Microporella can be recognized, M. arctica Norman and M. klugei sp. nov. The first of these is characterized by a large ascopore divided by thin radial septa and situated close to the proximal rim of the orifice. Microporella klugei sp. nov. differs in having a smaller, undivided ascopore situated in a more proximal position on the frontal shield. Both Arctic species are notable among Microporella species for having a high proportion of autozooids without associated avicularia.     

Deep-water crisiids (Bryozoa: Cyclostomata) from the northeast Atlantic Ocean

Eight Crisia and two Bicrisia species are recorded from the Celtic Sea (330–1175 m, Thalassa, 1973) and from both sides of the Straits of Gibraltar (110–903 m, Cryos, Balgim). Two new species are described: Crisia pyrula n. sp., and Bicrisia gibraltarensis n. sp. Systematics and morphology of five other species are detailed. A southern morphotype of C. aculeata is distinguished. Except for the boreal species B. abyssicola, all species occur both in Atlantic and Mediterranean localities. The upper bathyal crisiid fauna (>200 m) is richer in the Celtic Sea than in the Gibraltar area (6 spp. vs. 3 spp). Only three crisiids seem to be true deep-water species. The crisiid stock from stations located in the Gulf of Cadiz in Atlantic water is twice as rich as (1) that from stations of the same area washed by the Mediterranean water outflow; (2) that from the Alboran Sea.     

A new species of Exitomelita (Amphipoda: Melitidae) from a deep-water wood fall in the northern Norwegian Sea

The recently erected amphipod genus Exitomelita (Tandberg et al., 2012) has so far been found only associated with the deep-water hydrothermal vent field “Loki's Castle” in the Norwegian-Greenland Sea. There it was found on the black smoker chimney walls as well as within fields of the tubeworm Sclerolinum contortum in sulphide- and methane-rich sediments surrounding the vent field. A new species has now been found in a large wood fall of pine at 2800 m depth close to this vent field. This group of amphipods is apparently confined to reduced habitats, and our data support the theory that the vent fauna in this area is closely related to fauna found on cold seeps and wood falls in the northernmost Atlantic and Arctic Oceans. Here we present morphological and molecular data and a short discussion of the habitat of the new species, in addition to a comparison with the previously described species of Exitomelita.http://www.zoobank.org/urn:lsid:zoobank.org:pub:2B0B3CC2-AB6A-4006-83BB-182280CB22B8     

Species of genus Schizotheca Hincks (Bryozoa,Cheilostomata) described in the Atlantic‐Mediterranean region,with notes on some species of Parasmittina Osburn

Material held in collections, originally ascribed to the genus Schizotheca and originating from the NE Atlantic and Mediterranean, is revised. Two new species are described: Schizotheca carmenae sp. nov. from Azores and Portugal, originally cited as Strophiella tubigera [sic], and Schizotheca buski sp. nov. from Cape Verde and Brazil, originally cited as Schizotheca fissa. Schizotheca talismani, also from Cape Verde, is redescribed from original material and transferred to the genus Parasmittina. The Atlantic species Schizotheca tuberigera is redescribed and a new synonymy is established. Schizotheca aviculifera, from Morocco, is also redescribed and a lectotype designated. A lectotype is also chosen for Schizotheca fissa, type species of the genus. Schizotheca lepida, from north France, is considered to be an unrecognizable species.     

Apodidymochelia,a new genus of gammaridean amphipod from the tropical Atlantic Ocean (Crustacea: Amphipoda: Didymochellidae)

Apodidymochelia castellata, new genus, new species is the second genus and fourth species in the rare and poorly known family Didymocheliidae. Apodidymochelia is separated from Didymochelia primarily on mandible structure. This record extends the known range of the family into the Atlantic Ocean.     

Observations of water-flea Daphnia magna and avian fecalia in rock pools: is traditional natural history reporting still relevant for science?

Unexpected observation of freshwater invertebrate Daphnia magna in temporary rock pools on a small island off the Norwegian Atlantic coast confirms colonising ability, mediated through avian dispersal. Robust diapausal eggs of D. magna pass the gut of migrating geese and subsequently hatch in environments where such waterfowl forage and rest along migrating routes. The incubation experiment demonstrates that decomposing fecalia of geese constitute sufficient feed to support developing populations of D. magna in experimental oligotrophic conditions. The findings also show that D. magna is highly adapted for colonisation of temporary pools north of the Arctic Polar Circle, with excellent tolerance to low temperatures. Discussion part I relates the findings to published evidence on avian transport of invertebrate propagules, such as correlations between migration patterns of waterfowl and geographical patterns of aquatic invertebrate diversity. Discussion part II reflects on academic cultures, epistemological aspects of natural history reporting, the presence of a whale cadaver as an ecological indicator and the relevance of simple observation as a starting point for further discourse.     

A new species of stoloniferous octocoral (Cnidaria: Alcyonacea) from the south-western Indian Ocean

A new species of stolonate octocoral referable to the genus Scleranthelia Studer, 1878 (family Clavulariidae), is described from the East London and Durban regions of South Africa. The species is frequently encountered by dredge at depths ranging from 85 to 340 m. Scleranthelia thomsoni sp. nov. has been confused with the northern Atlantic species S. rugosa (Pourtalés, 1867) (= S. musiva Studer, 1878) by previous authors, but a comparison of material representing both species has shown them to be distinctly differentiated.     

Zoogeography and evolutionary ecology of the genus Platorchestia (Crustacea,Amphipoda, Talitridae)

ABSTRACT

Species of the genus Platorchestia occur both in the northern hemisphere (18 species) and southern hemisphere (three species plus a synanthropically introduced species in South America and South Africa). The greater number of endemic Platorchestia species in the North Pacific Ocean suggests that it could be the epicentre of evolution for this genus. North-western Pacific Platorchestia includes 15 species which occupy five ecotopes: wrack (seven species), terrestrial leaf litter (five species), freshwater (one species), marsh (one species) and tentatively present in caves (one species). North-eastern Pacific Platorchestia includes only one putative driftwood specialist, with no other species found in North American coastal habitats. This compares with three good endemic Platorchestia species (plus two putative additional species) and only two ecotopes: wrack (three species) and freshwater (two species) from the North Atlantic Ocean, inclusive of the Gulf of Mexico and Mediterranean Sea. Insufficient data is available to consider Platorchestia zoogeography for the Arabian Sea and Bay of Bengal. Synanthropic dispersal involving Platorchestia in Polynesian outrigger canoes, or in solid ballast carried in the holds of wooden sailing ships has been identified as a potential complicating factor in the zoogeography of this genus. Platorchestia is proposed to have arisen on Laurasia and is therefore basically a northern hemisphere genus. Questions concerning Platorchestia zoogeography and evolutionary ecology are posed and two methods (more intensive field sampling and molecular genetics) are suggested to be the way to solve them.     

An abyssal species of Sagitta (Chaetognatha) from the North East Atlantic

A Chaetognath species new to science, Sagitta abyssicola is described from specimens taken at abyssal depths (3500–4000 m) in the north east Atlantic Ocean and comparisons are made with related species of the ‘planctonis’ group namely S. planctonis Steinhaus, 1896, S. zetesios Fowler, 1905 and S. marri David, 1956. Ecological data are provided.     

Lepeophtheirus pectoralis (O. F. Müller, 1776); a description,a review and some comparisons with the genus Caligus Müller, 1785

Summary

The parasitic copepod Lepeophtheirus pectoralis (Müller, 1776) is described. A review of the hosts indicates that this species is primarily a parasite of members of the family Pleuronectidae although it has been recorded from representatives of ten other families of fishes. The geographical range of L. pectoralis includes the North Eastern Atlantic Ocean, the western part of the Baltic Sea and the White Sea. The similarities between Lepeophtheirus Nordmann, 1832 and Caligus Müller, 1785 are discussed and it is concluded that the only constant morphological discriminant between these two genera is the presence or absence of lunules.     

Two zoogeographically remarkable mite species from Finland (Acari,Oribatida, Oribotritiidae)

Species of the genus Mesothuria (fam. Synallactidae) occurring in the Atlantic Ocean are revised. The genus includes 25 valid species, nine of them known from the Atlantic. The new species Mesothuria milleri sp. nov. is described from the north-east Atlantic. It is argued that the genus Zygothuria, established by Perrier in 1898 and recognized later only by Deichmann, should be maintained as a separate genus. Mesothuria and Zygothuria differ in body form, arrangement of ambulacral appendages, and structure of segments of calcareous ring and ossicles from the body wall. The six known species of Zygothuria are reviewed. Zygothuria oxysclera, a former variation of Zygothuria lactea, is proposed as a valid species. Identification keys to species of the genus Zygothuria and Atlantic species of the genus Mesothuria are provided. Data on the life history and reproductive biology of Mesothuria milleri and Zygothuria lactea are given. Both species are common in the north-east Atlantic.     

First record of the genus Atlantistylis Reyss, 1975 (Crustacea: Cumacea) from the North Atlantic,with the description of a new species

A new species of the genus Atlantistylis Reyss, (Diastylidae) is described from the Atlantic Frontier Margin (North‐East Atlantic). This is the first record of the genus Atlantistylis from the North Atlantic. The new species Atlantistylis borealis can be recognized by the presence of spines on the frontal and lateral lobes of the carapace combined with their absence on the pereon and pleon; the first pereopods are very long. The small telson with two small apical acuminate setae and the absence of pleopods in the male are characteristic of the genus.     

Calanoides natalis Brady, 1914 (Copepoda: Calanoida: Calanidae): identity and distribution in relation to coastal oceanography of the eastern Atlantic and western Indian Oceans

Until recently, Calanoides carinatus s.l. was assumed to be very widespread in the upwelling systems of the Atlantic, Indian and western Pacific Oceans. Molecular data, reported here, show that Calanoides from the eastern Atlantic and Arabian Sea are one species and distinct from C. carinatus s.s. The name Calanoides natalis Brady, 1914 is available for this species, which is fully re-described. The illustration by Brady of the male fifth leg and the currently reported genetic data lead us to conclude that C. natalis is distributed from the Bay of Biscay southwards along the eastern Atlantic, around the Cape of Good Hope, and northwards along the western boundary of the Indian Ocean as far as the Arabian Sea. A by-product of this study is the recognition that Calanoides macrocarinatus is a junior synonym of Calanoides brevicornis. Females of C. natalis are easy to distinguish morphologically from C. carinatus s.s. but are more similar to C. brevicornis, apart from size differences. From physical oceanographic evidence we conclude that the Indian Ocean is currently the upstream part of the distribution of C. natalis. Calanoides philippinensis is known to extend into the eastern Indian Ocean at tropical latitudes. It is not known if it is C. philippinensis that has been recorded along the western coast of Australia. An apparently undescribed species of Calanoides occurs on the eastern Australian coast.     

Les espèces atlantiques du genre Eumunida Smith, 1883 (Crustacea: Decapoda: Chirostylidae)

Specimens of the genus Eumunida have been studied from various localities in the Atlantic Ocean. Comparisons of specimens from northwest and southwest Africa with material of E. picta from the western Atlantic Ocean has revealed two new species: E. bella nov. and E. squamifera sp. nov.

E. squamifera from the coast of Namibia, South West Africa, is distinguished from the two other atlantic species by a scaley striation of the carapace.

The northwest African E. bella and the western Atlantic E. picta, type of the genus, are closely related species, but differ from each other by the number and size of carapace marginal spines, shape of the anterior margin of the third thoracic sternum, and the ridges on the second abdominal segment. Their coloration is also different.

One specimen from the Tasman Sea identified by Gordon in 1930 as E. picta represents a further new taxon, E. australis sp. nov. It is readily distinguished from the three Atlantic species by the number of carapace anterio-lateral spines and the long acute projections of the third thoracic sternum.

All these species belong to the group A, as defined by Gordon (1930).     

Deep-sea Tanaidacea (Crustacea) of the North-east Atlantic: the tribe Agathotanaini

The tanaidacean tribe Agathotanaini, which was formerly the family Agathotanaidae, is well-represented in the Rockall Trough and Bay of Biscay areas of the North-east Atlantic. Five species have been recorded from depths of 1160–4829 m. Agathotanais ingolfi is the most numerous and one of the most widely distributed tanaidacean species in the region, and is often predominant in epibenthic sled samples from 1500–2500 m. Less numerous and frequent are three new species of Paragathotanais: P. nanus, P. robustus and P. gracilis. The first two are bathyal in distribution, and the last is abyssal. A new monospecific genus is established for Metagathotanais insulcatus, which has been recorded from the deepest part of the study region (4600–4800 m). Males of this tribe are characterized by their rigid pleopods bearing short terminal setae, and are otherwise very similar to the females. A key is provided for the identification of agathotanaids from the North-east Atlantic, including Agathotanais hanseni, and the genera Allodaposia and Paranarthrura, which should also be classified in the Agathotanaini.     

Revision of the American Pupisoma species (Gastropoda: Pupilloidea)

The American species of Pupisoma Stoliczka (Gastropoda: Pupilloidea) are revised. Five species are recognized. Pupisoma puella Hylton Scott has been synonymized with P. dioscoricola (C. B. Adams). This species occurs from southern USA through the Caribbean and Central America to the Galapagos Islands and to southern Brazil and northern Argentina. Pupisoma galapagorum Pilsbry, P. bailyi Pilsbry, and P. latens Hylton Scott have been synonymized with P. comicolense H. B. Baker. This species is distributed from Mexico to the Galapagos Islands, southern Brazil, and northern Argentina. Pupisoma costulata sp. n. from Andean forests in Colombia is described as new. The range of P. macneilli (Clapp) extends from southern USA through the Caribbean and Central America to southern Brazil and northern Argentina. A neotype has been designated for P. mediamericanum Pilsbry. Pupisoma michoacanense Pilsbry is a synonym of this species. This species occurs from Mexico to Colombia and on Jamaica.     

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.