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The species composition and distribution of marine invertebrates varies greatly in different bathymetric regions. Nevertheless, the process of exchange between faunas of different depths has occurred repeatedly throughout the evolution of marine biodiversity. In high latitudes, this process should occur most actively due to absence of strong temperature stratification. The presence of physiological adaptations that allow northern shallow-water organisms to live at greater depth has been demonstrated in a series of experiments. However, known cases of recent colonization by species confined to a highly productive shallow-water zone in unusually deeper Arctic habitats are almost absent. The present study describes finding of population of the gastropod Onoba aculeus (Gould, 1841) in two samples from the lower continental shelf of the Arctic Ocean. Onoba aculeus is a shallow-water amphiatlantic species widely distributed in the temperate regions. The finding reported here is at the same time, the northernmost, easternmost, and most remote from the coast location. We assume that the detection of molluscs indicates the presence of an abundant isolated population in the region. [ABSTRACT FROM AUTHOR]

The intertidal zone of Jeju Island, Korea, is characterized by well-developed volcanic rocks with high wave action. During low tide, numerous small tidal pools are formed on the rocky intertidal zone, which provide shelter and habitats for benthic organisms. Previous investigation indicated that many species of micromolluscans inhabit the tidal pools; however, only a few studies have reported the ecology and identification of these microshells. In this study, we have identified a microgastropod, Ammonicera japonica Habe, 1972 (Omalogyridae), from a tidal pool on the southern coast of Jeju Island. Morphological identification of the species was based on scanning electron microscopy (SEM) of the protoconch and teleoconch. A. japonica was found to be associated with encrusting coralline algae distributed on the bottom of the tidal pools. This is the first report of A. japonica from Korea, and the specimen was registered at the National Marine Biodiversity Institute of Korea (MABIK MO00157413).

Zospeum percostulatum sp. n. from Cueva de La Herrería (Llanes, Asturias) is described. It is characterized by a relatively large shell (1.4-1.8 mm height), conical, with ovate aperture, continuous peristome and thickened parietal callus; shell costulate except two first whorls; without any sort of inner formations. It is the first clearly costulate Iberian species, filling a morphological gap in the Iberian clade, and the largest species from the Cantabrian region, being the first species described from Asturias. [ABSTRACT FROM AUTHOR]

Keban metamorphites located at the orogenic belt of the Eastern Taurides is an allochtonous union metamorphized at the greenschist facies comprised of several nappes. Contrary to the massives around it, the aging of the union is not quite satisfactory due to the lack of fossil data. Permo-Triassic/Permo-Carboniferous ages have been used until now for the age of the metamorphites that are stated to be located only at a single location, the species of which have not been determined and which are based on two fossil data. However, for the first time in this study, “ microgastropods ” have been found at Early Triassic age related with The Great Dying at the end of the Permian inside the clastic limestones at the base levels of the Nimri Formation which is one of the lower nappes of the Keban metamorphites. Again, trace fossils Planolites , Rhizocorallium , Thalassinoides , Helminthopsis and (?)Protovirgularia have been determined for the first time in the layered crystallized limestones at the medium levels of the Nimri Formation. This ichnofabric is frequently observed in the Middle Triassic aged limestones at Germany, Poland, Austria, Italy and the Taurides and is known as the “vermicular limestone facies”. The ages of Keban marble, Delimehmet and Süleymanlı Formations, tectonically located on the Nimri Formation, are evaluated by regional correlations as Middle-Late Devonian, Late Devonian and Early Carboniferous, respectively. In addition, probably pre-Triassic aged, dark green colored metadiabase dykes have been inserted in the Delimehmet formation in relation with the Variscan Orogeny. Regional correlations with other units and massives indicate that the Keban metamorphites that have deposited at the farthest north of the south branch of the Neo-Tethys ocean paleogeographically may be the continuation of the Bolkardağı Union at the east rather than the Alanya and Geyikdağı Unions. [ABSTRACT FROM AUTHOR]

The external morphology and movement of a living specimen of the minute gastropod Sukashitrochus pulcher (Petterd, 1884) is reported and the findings compared with the reported morphologies of other species of Sukashitrochus and scissurellids more generally. Although some scissurellids exhibit swimming behaviour, there is no evidence that temperate Australian Sukashitrochus species possess this ability. [ABSTRACT FROM AUTHOR]

The family Iravadiidae is found to be polyphyletic in a molecular phylogenetic analysis using a subset of Australian taxa. Taxa previously assigned toIravadiaform a monophyletic clade, butNozeba topaziacaclusters withAuricorona queenslandican. gen. and n. sp. in an unnamed family related to Tornidae.Aenigmula criscionein. gen. and n. sp., an iravadiid-like species from the Northern Territory, belongs to another unnamed family related to Caecidae, Calopiidae and Clenchiellidae. A systematic revision of some Australian ‘iravadiids’ raises the subgeneraFluviocingulaandPseudomerelinato full generic rank and reinstates two former synonyms ofIravadia (Fairbankia), PellamoraandWakauraia, as genera. The species formerly identified in Australia asIravadia quadrasiis recognised as three allopatric species;Iravadia pilbaran. sp. and the reinstated speciesIravadia goliathandIravadia quadrina. Pellamora splendidan. sp., from Western Australia, is recognised as distinct fromPellamora australis, andFluviocingula superficialisn. sp. fromFluviocingula resima. Wakauraia fukudain. sp. is recorded from central Queensland. http://zoobank.org/urn:lsid:zoobank.org:pub:1B9917F6-48B2-4597-85C1-F90BA9093475 [ABSTRACT FROM AUTHOR]

The Australian and East Timorese species belonging to the truncatelloid family Stenothyridae are revised using molecular data and morphological characters from the shell, operculum, radula and external and reproductive anatomy. The Australian speciesStenothyra australisis redescribed and two previously recognised subspecies are shown to be synonyms. The New Guinean speciesStenothyra paludicolavan Benthem Jutting, 1963 is redescribed and recorded from the Torres Strait region of northern Australia, and two new subspecies ofS. paludicolaare described from the Northern Territory and East Timor;S. paludicola topendensisn. subsp. andS. paludicola timorensisn. subsp. respectively.Stenothyra gelasinosan. sp. is described from Australia, comprising three allopatric subspecies;S. gelasinosa gelasinosan. sp. and n. subsp. from the eastern seaboard,S. gelasinosa phrixan. subsp. from northern Australia andS. gelasinosa apiosan. subsp. from the Pilbara region of Western Australia.Stenothyra frustillumis considered anomen dubium. Molecular phylogenetic analysis of these taxa and other Asian stenothyrids supports these systematic decisions and provides a preliminary interpretation of relationships within Stenothyridae. [ABSTRACT FROM PUBLISHER]

A fundamental problem in ecology, regardless of habitat or system, is understanding the relationship between habitats and assemblage of organisms. It is commonly accepted that differences in composition and surrounding landscape of habitats affect the diversity of assemblages, although there is not much empirical evidence because of difficulties of manipulating structure in many habitats. These relationships were examined experimentally, using habitats of artificial turfs that are colonized by diverse assemblages of gastropods. Each habitat was made of nine sub-habitats, which were sampled individually to allow tests of hypotheses about the effect of type of habitat and the influence of other adjacent sub-habitats on the colonizing assemblage. Turf habitats were deployed for 8 weeks on a rocky shore after which they were collected and the colonizing assemblages of gastropods sampled. Independently of the types of turfs combined to form different habitats, there were more species where there was more than one type of component in a habitat (i.e. structural diversity). The type of habitat (i.e. structural identity) itself had little or no influence on the colonizing assemblage. The number of species colonizing short-sparse and short-dense turfs was influenced by which type of habitat was adjacent. Thus, when units of one type (e.g. short-sparse turf) were added to a patch of habitat of long-sparse turfs, the number of species in short-sparse turfs was greater than in patches of the same type. This also increased total number of taxa in the whole patch of habitat. These results show how diversity of gastropods colonizing heterogeneous patches of habitat is influenced not only by the number of types of sub-habitats, but also by interactions with surrounding sub-habitats. These findings reiterate the importance of investigating the role of structure of habitats and of their surrounding landscapes across different systems, irrespective of their size or associated assemblages of organisms. [ABSTRACT FROM AUTHOR]

Very diversified and abundant benthic microgastropods and planktonic microgastropods (pteropods) from core NS93-12-25 could provide a glance of change of the sea level in the south continental shelf of the South China Sea since last 14 ka. Research shows that general sea level changes of this sea area were rising and later rising after a short period of falling in this period. In the range from the bottom of the core to the core depth of 200 cm, individuals in big size are common in microgastropods and Turritella filiola is very rich, signifying the environment of the inner continental shelf in the last deglaciation stage. In the core depth range of 200–150 cm the continuously getting light of the δ18O, the regularly decreasing of the percentage content of T. filiola and the high diversification of microgastropods indicate the rising of the sea level. Especially at the core depth range of 175–150 cm the pteropods became dominant, making sure the fact that the high sea level possibly occurred in the early Holocene. Channels of surrounding straits connecting the adjacent sea thus were opened. But at the core depth of about 100 cm T. filiola became very rich again. This possibly implies that there was a short term of the sea level falling, resulting in the temporal closure of the channels. In the core depth range of 55–50 cm the Scaliola’s representatives relatively develop and this may be inferred to the cooling of climate. [ABSTRACT FROM AUTHOR]