Bathyal cumaceans of the Catalan Sea (North-western Mediterranean): faunistic composition,diversity and near-bottom distribution along the slope (between 389 and 1859 m)

Deep-water epibenthic/suprabenthic species of Cumacea were studied in the Catalan Sea (Western Mediterranean). Samples (21) were taken at depths from 389 to 1859m, using a Macer-GIROQ type sledge, 32 cumacean species were collected. Diastyloides serratus and Leucon longirostris were the commonest species on the upper slope and middle slope, respectively. On the lower slope (1250–1859 m) dominance by any single species was not apparent and Cyclaspis longicaudata, Procampylaspis bonnieri and Platysympus typicus were the most abundant species. Two leuconids (Leucon cf. serratus, and Leucon (Crymoleucon) sp. A) were recorded for the first time in the Mediterranean Sea. The highest total abundance of cumaceans was encountered over the middle slope. Highest values of species richness and diversity (H') were registered at intermediate depths on the lower slope (1250–1355 m). The low H' value on the middle slope was attributable to the dominance of L. longirostris. Swimming coefficients calculated from near-bottom samples revealed intraspecific differences in the most abundant species. Thus, while mancas, juveniles, immature males and females, and adult females were captured almost exclusively in the lower level of the sledge, adult males of L. longirostris swam in the water column indistinctly between 10 and 140cm above the bottom. Similar trends, although less evident, have been established for other deep-sea cumaceans.     

Deep-living demersal fishes in the Catalan Sea (western Mediterranean) below a depth of 1000 m

An extensive survey of the deep-living fishes of the Catalan Sea (western Mediterranean) recorded 31 species in 19 families and 29 genera from 100 samples at depths between 960 and 2251 m. Chlorophthalmidae, Moridae and Macrouridae accounted for nearly 85% of all specimens taken. In biomass terms, Hexanchidae, Moridae, Alepocephalidae and Chlorophthalmidae were the most important families. A quantitative model of the bathymetric distribution of the species is presented. The ‘centre of gravity’ of species’ distribution and the habitat width, a measure of the distribution heterogeneity, are also given. Out of the 31 demersal species caught, the distributions of only 13 are centered below 1000 m. The Mediterranean deep-sea ichthyofauna is very impoverished in comparison with the adjacent Atlantic Basin fauna.     

Spatial distribution of ichthyofauna in the northern Alboran Sea (western Mediterranean)

This study describes the four main demersal fish assemblages identified along the continental shelf and slope (30–800 m depth) of the northern Alboran Sea (western Mediterranean), based on the analysis of the MEDITS (International bottom trawl survey in the Mediterranean) 12-year data series. We collected 186 fish species belonging to three classes, 24 orders and 69 families. Taxonomically, the order Perciformes was the most diverse, represented by 18 families and 58 species. Each assemblage had particular characteristics of abundance, biomass, mean fish weight and species richness. The geographical differences associated with the distribution of some species occurred within shelf assemblages. The middle slope was characterised by the highest similarity between samples, probably due to its lower environmental variability compared to that of the other assemblages.     

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.     

Monstrilloids (Crustacea: Copepoda) from the Mediterranean Sea (Northern Adriatic Sea), with a description of six new species

Monstrilloid copepods collected during zooplankton surveys carried out over several years (2009–2016) in the Gulf of Trieste, northern Adriatic Sea, were examined. A total of seven species were found, of which six are undescribed, five of Cymbasoma and one of Monstrilla. These new species are described, illustrated and compared herein with its known congeners. Two of them are related to the C. rigidum species complex. One of these species is described based on both the male and the female; sexes were linked by identical details of the cephalic structure and the antennulary armature. Two previous reports of females attributed to C. tumorifrons from the Mediterranean relate to specimens that in fact belong to a new species, C. mediterranea. The most abundant species was M. grandis, which had a remarkable aggregation around the Trieste harbour in 2015. Male and female specimens of this assumedly widespread species were examined and the observed intra-specific morphological variability is reported and compared with previous illustrated reports; this nominal species probably this nominal species, probably represents a species complex. The addition of the new species here described brings the number of nominal species in the Mediterranean-Black Sea region to 26.

www.zoobank.org/urn:lsid:zoobank.org:pub:3D4B38E4-CCCD-4BD6-AC57-B59343A865F7     

Alien polychaete species (Annelida: Polychaeta) on the southern coast of Turkey (Levantine Sea,eastern Mediterranean), with 13 new records for the Mediterranean Sea

The examination of benthic material collected from different depths and habitats along the southern coast of Turkey (Levantine Sea, eastern Mediterranean) in September and October 2005 revealed 30 alien polychaete species belonging to 15 families. Thirteen species (Pisione guanche, Linopherus canariensis, Onuphis eremita oculata, Lumbrineris perkinsi, Dorvillea similis, Timarete caribous, Pherusa parmata, Pherusa saldanha, Streblosoma comatus, Polycirrus twisti, Laonome triangularis, Branchiomma bairdi and Janua steueri) are new to the Mediterranean fauna, 24 species are new to the Turkish fauna and 27 species are new to the Levantine coast of Turkey. The specimens collected from the Levantine coast of Turkey and northern Cyprus that were previously identified as Linopherus acarunculata and Branchiomma boholense are reidentified as L. canariensis and B. bairdi, respectively. In the light of present knowledge, the previous reports of Lumbrineris inflata and Streblosoma hesslei from the Mediterranean (Italian coast) could refer to the species L. perkinsi and S. comatus, respectively. The species new to the Mediterranean Sea are redescribed and discussed.     

Taxonomic studies on Tasmanian phytal amphipods (Crustacea): the families Anamixidae,Leucothoidae and Sebidae

Three amphipods new to science from Tasmania are described herein as Leucothoe ctenochasma sp. nov., L. neptunea sp. nov. (Leucothoidae) and Seba chiltoni sp. nov. (Sebidae). The hyperadult male of ‘Leucothoides’ yarrega Barnard is described as Anamixis yarrega (Barnard) (Anamixidae). Range extensions are reported for Leucothoe boolpooli, L. commensalis and ‘Leucothoides’ yarrega. Leucothoella gracilis was also collected. The morphology of female and small male Leucothoe boolpooli is described. The Anamixis record is the first for the genus outside tropical waters. A key to the world Anamixis spp. in included.     

Abundance and diversity of decapod crustaceans in the deep-Catalan Sea (Western Mediterranean)

The deep-slope decapod fauna of the Catalan Sea was extensively sampled with an OTSB-14 bottom trawl. A total of 67 bottom tows were taken from 1985 to 1989 at bottom depths ranging from 552 to 2261 m. Species in which abundance decreased with depth were Plesionika acanthonotus, Polycheles typhlops, Calocaris macandreae and Geryon longipes. Highest densities of Acanthephyra eximia, Stereomastis sculpta, and Nematocarcinus exilis were attained at the greatest depths studied. Total abundance, biomass and species richness for decapod crustaceans as a whole decreased with depth. Maximum decapod biomass and diversity occurred on the upper-middle slope on soft bottoms in the Catalan Sea and in all regions for which data were available. In the Catalan Sea, an oligotrophic area, the abundance of decapods as a group seemed to be higher than in north-Atlantic eutrophic regions. In these latter areas, other deep-sea benthic invertebrate groups, particularly ophiuroids, predominate.     

Synopsis of the life cycles of Digenea (Platyhelminthes) from lagoons of the northern coast of the western Mediterranean

The present document reports on the large amount of data relating to digenean parasites recorded from or known to be present in various hosts in lagoons of the northern coast of the western Mediterranean, which has been compiled from the literature of more than a century. In these lagoons, at least 72 nominal species of digeneans have been recorded. This total corresponds to approximately 12% of the 584 “marine” digenean species reported for Europe. Data are provided on the life cycles of 56 digenean species. The life cycle has been totally elucidated for 44 species (25 from fish, 19 from birds), and partly for the other 12 species (seven from fish, five from birds). This means that the life cycle is known for 61.1% of the recorded fauna (44/72) and partly for 16.7%, but remains unknown for 22.2%, making it, in this respect, one of the best understood digenean marine faunas in the world. In addition, a checklist is provided dealing with the cercarial and metacercarial forms recorded from lagoons of the northern coast of the western Mediterranean, which have been described only on the basis of characters of these larval stages and which remain without demonstrated links to a corresponding sexual adult stage in a vertebrate.     

Biogeography of amphipods (Crustacea: Amphipoda: Gammaridae) from the central Zagros Mountains,Iran, with descriptions of two new species

Seven species of gammarid amphipods were studied in the relatively small province of Charmahal-Va-Bakhteyari in the central Zagros Mountains, Iran. Of these, four are previously known (Gammarus proiectus, G. komareki, G. syriacus and G. balutchi), one is a new record for the region (G. pseudosyriacus) and two are new species (G. lordeganensis and G. bakhteyaricus). From the taxonomic point of view, head microsculpturing characters were found to be reliable as discriminating sets of characters useful in species identification. Habitat diversification and climatic fluctuations appear to be the main factors for species diversity of the area, and the Zagros Mountains act as a geographical barrier to species distribution.     

A new genus and species of the family Mantridae (Copepoda: Cyclopoida) infesting the bivalve Pseudochama retroversa from the Seto Inland Sea,western Japan

Chamicola nagasawai n. gen., n. sp., belonging to the bivalve-infesting cyclopoid family Mantridae, is described from the Seto Inland Sea, western Japan. This is the first recorded occurrence in the Pacific Ocean of the family, which previously accommodated only two genera, Mantra and Nearchinotodelphys. The parasite was found in the mantle cavity of Pseudochama retroversa (Lischke) (Family Chamidae), but did not infect Chama japonica (Lamarck). The prevalence and intensity of C. nagasawai in P. retroversa ranged from 11.3 to 25.0%, and from 1.0 to 2.6, respectively. Considering the host affinity and distribution of ancestral and derived character states, the new genus seems to be more closely related to Mantra than to Nearchinotodelphys.     

Biology and life cycle of Tmetonyx similis (G. O. Sars, 1891) (Amphipoda,Lysianassidae), a scavenging amphipod from the continental slope of the Mediterranean

The present study focused on the biology and life cycle of Tmetonyx similis, a scavenging amphipod inhabiting the continental slope of the north‐western Mediterranean. All the categories of individuals were observed in the samples. The emergence of offspring occurs in successive cohorts. The lifespan of the females is longer than that of the males, but the sex ratio is strongly in favour of the males. The fecundity was found to be lower than that of the other female crustaceans present in these samples. The growth pattern was modelled. A strong correlation was observed between the length and the weight of the animals collected. Several hypotheses are proposed to explain a sex ratio in favour of males. This result may be explained by a migratory process of the females of T. similis. A comparison of the reproduction strategy is given for the three main scavenger crustacean species (amphipods and isopod) collected in this area.     

Temporal variation and structure of macro-epifauna associated with macrophytes in the Bizerte lagoon (Tunisia,SW Mediterranean Sea)

The temporal variation in composition and abundance of the macro-epifauna associated with seaweeds (Ulva lactuca, Cladophora sp., Gracilariopsis longissima and Gracilaria bursa-pastoris) and seagrass (Cymodocea nodosa) was investigated at Menzel Jemil station in the Bizerte lagoon. Twelve replicate samples (25 x 25 cm frame) were collected monthly from October 2009 to September 2010. Sampling data yielded 21,575 invertebrate specimens from floating seaweeds and the seagrass, belonging to 40 taxa, of which 18 species were arthropods, 13 molluscs, three echinoderms, three fishes, two polychaetes and one cnidarian. Crustaceans were the most dominant and the most species-rich group and Idotea balthica basteri the most abundant species, accounting for 28.94% of the total abundance. Minimum (9.25 ± 5.56 species) and maximum (19.75 ± 3.2 species) values of mean species richness were observed in December and June, respectively. Species richness and density of macro-epifauna showed similar trends to plant biomass and the highest values of both indices coincided with periods of maximal plant biomass. Mean values of Shannon’s index H′ and evenness J′ were low, ranging from 0.34 ± 0.02 bit to 1.08 ± 0.06 bit, and from 0.23 ± 0.03 to 0.52 ± 0.07, respectively. The high dominance of herbivores and detritivores highlighted the substantial role played by macrophytes as food source for associated macro-epifauna species. Multivariate analyses also indicated significant seasonal differences for the macro-epifauna assemblage and revealed significant relationships with environmental variables. According to the canonical correspondence analysis, concentrations of phosphates and nitrites, and temperature were the variables that explained the variation of the macro-epifauna abundance in the Bizerte lagoon.     

New species of oribatids from western Colorado (Acarina: Cryptostigmata, Suctobelbidae)

A new species of Suctobelba, S. tumulata, and a new genus and species, Parisuctobelba septenia, are described from collections of oribatids taken in coal strip-mining spoil banks near Hayden, Colorado. The new species are compared with members of the family from North America and Europe. The new genus is differentiated by a smooth, narrowed sensillum and seven pairs of genital setae. Taxonomic and ecological data are also discussed.     

Biology and life cycle of Scopelocheirus hopei (A. Costa, 1851), a scavenging amphipod from the continental slope of the Mediterranean

The biology of Scopelocheirus hopei, a deep-sea (500 m) scavenging amphipod that lives on the continental slope of Mediterranean canyons, was studied. Animals were collected using a baited trap. A new method was developed for reproducibly measuring the exact length of the animals. All the categories of individuals were always present in the samples. The emergence of offspring occurs in successive cohorts. Individuals of the two sexes do not grow at the same rate: the males grow more quickly than the females, but their lifespans are shorter. The males are always less numerous than the females. Two production cycles occur. The females produce offspring all year round. The mean fecundity was found to be 218 eggs per female. The growth pattern was modelled. A strong correlation was observed between the length and the weight of the animals collected. Several hypotheses are proposed to explain the results obtained.     

Ampithoid amphipods from the South Pacific: Papua New Guinea,French Polynesia and New Caledonia

This paper documents 13 known and seven new species of Ampithoidae from three South Pacific locations: Papua New Guinea; the Austral Isles, French Polynesia; and the Loyalty Islands, New Caledonia. The new species Ampithoe ricaudyana, Ampithoe takeuchii, Cymadusa lituus, Cymadusa paradisaea, Plumithoe boulari, Sunamphitoe kanaka and Sunamphitoe tjiboui are described. http://www.zoobank.org/urn:lsid:zoobank.org:pub:590B4276-1DFA-40C1-B562-A7B5FC1E6A5C     

Courtship behavior in Rhinoclemmys areolata from western Tabasco, Mexico (Testudines: Emydidae)

Observations in nature and captivity reveal that members of the population of Rhinoclemmys areolata of western Tabasco, Mexico, exhibit underwater courtship and mating and appear to lay one egg per nest.