Phalium flammiferum breviculum Tsi & Ma, 1980 has long been regarded as a subspecies of Phalium flam- miferum (R & ouml;ding, 1798) or sometimes treated as its synonym. In this study, integrative morphological and molecular phylogenetic analyses of P. flammiferum breviculum Tsi & Ma, 1980 and P. flammiferum flammiferum (R & ouml;ding, 1798) from Chinese waters demonstrate that they represent two distinct species. Morphologically, the two species differ primarily in discrete characters of shell sculpture, particularly in the number of spiral cords and varices. Geometric morphometric analyses and mapping of landmark configurations onto the phylogeny indicate that variation in shell outline is largely continuous and only weakly associated with phylogenetic relationships. Phylogenetic analyses reconstructed by Bayesian inference using concatenated mitochondrial (COI) and nuclear (28S rRNA) genes and species delimitation analysis (ASAP) support the separation of the two species. Herein, we formally elevate Phalium flammiferum breviculum Tsi & Ma, 1980 to species rank.
Some bathyal Thyasiridae from the Faroe-Shetland Channel and Rockall Trough in the North-East Atlantic are described. Four new genera are introduced for species formerly included in Thyasira s.s. namely, Rhomb-axinus gen. nov. with type species Cryptodon equalis A.E. Verrill & K.J. Bush, 1898, Thyasirella gen. nov. with type species Cryptodon obsoletus A.E. Verrill & K.J. Bush, 1898, Cryothyas gen nov. with type species Axinus flexuosa var. rotunda Jeffreys, 1881, and Odontothyas gen. nov. with type species Axinus succisa Jeffreys, 1876. The generic status of Mendicula is discussed and M. oblonga (Monterosato, 1880) is transferred to Adontorhina. Comparisons with related taxa from across the entire North Atlantic and adjacent Arctic Ocean are made. Four new species are described: two from the Rockall Trough, Rhombaxinus stellaris sp. nov. and Thyasirella rhamphos sp. nov.; one from east Greenland, Cryothyas milnelandensis sp. nov.; one from the abyssal Norwegian Sea, Mendicula atomus sp. nov. Cryothyas rotundus (Jeffreys, 1881) comb. nov. is recognized from type material discovered in The Natural History Museum (London) and is widespread throughout the Faroe-Shetland Channel from 800-1100 m and ranges from Newfoundland, west and east Greenland, Iceland, Jan Mayen, Svalbard, northern Norway, and into the Barents Sea. It is the earliest available name for all previous records of Thyasira dunbari Lubinsky, 1976, except for the type mate-rial of that species from the Canadian High Arctic, which is a separate species and retains its original name. A form of Thyasirella obsoleta (A.E. Verrill & K.J. Bush, 1898) is present at depths below 500 m in the Faroe-Shetland Chan-nel but rarely overlaps with the range of Odontothyas succisa (Jeffreys, 1876) comb. nov. that was found predomi-nantly around the shelf edge at 200-300m. Mendicula pygmaea (A.E. Verrill & K.J. Bush, 1898) was widespread in the Faroe-Shetland Channel at depths from 700 to 1200 m and was found to have a range that included the type locality of off Massachusetts north to Jan Mayen, Svalbard, northern Norway and the Barents Sea. Despite small variations, none are significant enough to warrant the recognition of new species. Mendicula pygmaea is compared with M. ockelmanni (Keuning & Schander, 2010), M. ferruginosa (Forbes, 1844), and two other small Arctic species, Axinulus careyi Bernard, 1979 and Thyasira ottoschmidti Gorbunov, 1946. Mendicula atomus sp. nov. is described from abyssal depths in the Norwegian Sea. A short discussion on thyasirid systematics concludes the paper.
Two new species of operculate land snail, Thomeomaizania cathyae sp. nov. and Afroditropis delimai sp. nov., are described from the island of Sao Tome in the Gulf of Guinea. Both are very likely to be single-island endemics. Whether these species should be classified in the Maizaniidae or Cyclophoridae is uncertain pending further study. However, the structure of the operculum, which is distinctive and formed of at least three layers, the outermost comprising a series of tightly coiled spiral lamellae, would suggest that they most likely belong to the Cyclophoridae. Shells of the six operculate species currently known from the island, and details of their opercula, are illustrated. An identification key is provided. Records of three non-operculate terrestrial gastropod species are also given, raising the total number of terrestrial molluscs known from Sao Tome from 59 to 64.
Shaanxi Province is divided by the transition line between the vegetation zones of subtropical evergreen and temperate deciduous broadleaf forests, which sets a limit to northward expansion for members of the clausiliid subfamily Phaedusinae. Due to this constraint and a modest interest of malacologists only eight, mostly widespread clausiliid species have been recorded reliably from this province. Here we introduce Euphaedusa vitrea sp. nov., Streptodera chertoprudi sp. nov., and Streptodera qinlingensis sp. nov., which were found during a 2010 trip to the Qinling Mountains in southern Shaanxi. Intriguingly, the new Streptodera species are sinistral members of a genus that previously was considered monotypic and dextral. The three new, apparently narrow endemic species suggest a higher-than-expected diversity of clausiliids in the forested areas of southern Shaanxi.
Land-snail assemblages in the Brazilian Atlantic Forest remain poorly studied despite this biome's exceptional biodiversity and high endemism. We investigated patterns of microhabitat use in a land-snail assemblage from the Sooretama Biological Reserve, southeastern Brazil, testing three predictions: (1) that more abundant species would occupy broader microhabitat ranges; (2) that species would show non-random associations with particular microhabitats; and (3) that species sharing the same microhabitat would exhibit convergent shell morphologies. We recorded 440 individuals from 30 species and 12 families across 24 standardised plots, assigning each individual to one of five microhabitat categories: ground, leaf litter, vegetation, tree trunk, and tree leaves. Species differed significantly in their distribution across microhabitat categories (G-test: G = 943.51, p < 0.0001), and 60% of species were significant indicators of a particular microhabitat (IndVal, p < 0.05). No significant relationship was detected between species abundance and standardised Levins' niche breadth (Spearman: p = 0.251, p = 0.197), and Prediction 1 was not supported. Hierarchical cluster analysis resolved the assemblage into four groups corresponding to distinct microhabitat-use patterns, showing strong correspondence with shell shape: groups associated with arboreal and ground microhabitats were predominantly high spired (80-100%), while the group associated with leaf litter was predominantly low spired (80%). Shell shape differed significantly among microhabitat categories (Kruskal-Wallis test: H = 274.43, p < 0.0001), with leaf litter differing from all other microhabitats in post-hoc comparisons. Phylogenetically stratified PERMANOVA confirmed that microhabitat accounted for 83.8% of the variation in species composition after controlling for superfamily-level non-independence (F = 32.345, R-2 = 0.838, p = 0.001). Our results extend the bimodal shell-shape framework to the Brazilian Atlantic Forest and provide a quantitative baseline for comparative studies of land-snail assemblages in this threatened biome.
