@article {241, title = {Systematics of the Neritilia rubida complex (Gastropoda: Neritilidae): three amphidromous species with overlapping distributions in the Indo-Pacific}, journal = {Journal Molluscan Studies}, volume = {69}, year = {2003}, month = {08/2003}, pages = {273-284}, author = {Kano, Yasunori} } @article {242, title = {Major adaptive radiation in neritopsine gastropods estimated from 28S rRNA sequences and fossil records}, journal = {Proceedings. Biological sciences / The Royal Society}, volume = {269}, year = {2002}, month = {2002 Dec 7}, pages = {2457-2465}, abstract = {A well-supported phylogeny of the Neritopsina, a gastropod superorder archaic in origin, radiated ecologically and diverse in morphology, is reconstructed based on partial 28S rRNA sequences. The result (Neritopsidae (Hydrocenidae (Helicinidae + Neritiliidae) (Neritidae + Phenacolepadidae))) is highly congruent with the fossil records and the character distribution of reproductive tracts in extant taxa. We suggest that the Neritopsina originated in subtidal shallow waters, invaded the land and became fully terrestrial at least three times in different clades, by the extinct Dawsonellidae in the Late Palaeozoic and by the Helicinidae and Hydrocenidae in the Mesozoic. Invasion of fresh- and brackish waters is prevalent among the Neritopsina as the Jurassic and freshwater ancestory is most probable for helicinids. The Phenacolepadidae, a group exclusively inhabiting dysoxic environments, colonized deep-sea hydrothermal vents and seeps in the Late Cretaceous or Early Cenozoic. Submarine caves have served as refuges for the archaic Neritopsidae since the Early to Middle Cenozoic, and the marine neritopsine slug Titiscania represents a highly specialized but relatively recent offshoot of this family. The Neritiliidae is another clade to be found utilizing submarine caves as shelter by the Oligocene; once adapted to the completely dark environment, but some neritiliids have immigrated to surface freshwater habitats.}, author = {Kano, Yasunori and Chiba, Satoshi and Kase, Tomoki} } @article {243, title = {Anatomy and systematics of the submarine-cave gastropod Pisulina (Neritopsina: Neritiliidae)}, journal = {Journal Molluscan Studies}, volume = {68}, year = {2002}, pages = {365-384}, author = {Kano, Yasunori} } @article {264, title = {Taxonomic revision of Pisulina (Gastropoda: Neritopsina) from submarine caves in the tropical Indo-Pacific.}, journal = {Paleontological Research}, volume = {4}, year = {2000}, pages = {107-129}, author = {Kano, Yasunori and Kase, T.} } @article {230, title = {Hitchhiking behaviour in the obligatory upstream migration of amphidromous snails}, journal = {Biology letters}, volume = {5}, year = {2009}, month = {2009 Aug 23}, pages = {465-468}, abstract = {Migratory animals endure high stress during long-distance travel in order to benefit from spatio-temporally fluctuating resources, including food and shelter or from colonization of unoccupied habitats. Along with some fishes and shrimps, nerite snails in tropical to temperate freshwater systems are examples of amphidromous animals that migrate upstream for growth and reproduction after a marine larval phase. Here I report, to my knowledge, the first example of {\textquoteright}hitchhiking{\textquoteright} behaviour in the obligatory migration of animals: the nerite snail Neritina asperulata appears to travel several kilometres as minute juveniles by firmly attaching to the shells of congeneric, subadult snails in streams of Melanesian Islands, presumably to increase the success rate of migration.}, author = {Kano, Yasunori} } @article {235, title = {Usefulness of the opercular nucleus for inferring early development in neritimorph gastropods}, journal = {Journal of Morphology}, volume = {267}, year = {2006}, month = {2006 Sep}, pages = {1120-1136}, abstract = {The early ontogeny of gastropods (i.e., planktotrophic vs. nonplanktotrophic) may be inferable from the morphology of the protoconch in adult shells. The protoconch consists of both embryonic and larval shells in species with planktotrophic development; the embryonic shell forms in the intracapsular period and the succeeding larval shell gradually develops during the larval period. In nonplanktotrophic species, on the other hand, there is no additional growth of the larval shell and the protoconch consists exclusively of a relatively large embryonic shell formed prior to hatching. This "shell apex theory" has been applied to many species of shell-bearing gastropods, but biotic and abiotic erosion of the apex often prevents detailed examination of the protoconch and subsequent inferences about ontogeny. I examined the gastropod operculum to test its utility for predicting developmental mode, drawing on the Neritimorpha as model taxa. Most aquatic members of Neritimorpha were found to bear an operculum with a clearly demarcated nucleus; SEM observations reveal four types of nuclei, which correspond to different types of protoconch morphologies and observed ontogenies for the study species. The nucleus is secreted before metamorphosis, fits into the shell aperture of the larva, and reflects early ontogeny as morphology, as does the protoconch. Moreover, the apparently organic (rather than calcareous) composition of the nucleus makes it nearly invulnerable to erosion and very advantageous, compared to the protoconch, in this ecologically diverse group, whose habitats range from freshwater streams and mangrove swamps to rocky shores and deep-sea hydrothermal vents. The measurements of the nucleus are also valuable for taxonomic purposes, especially in the species identification of veliger larvae and juvenile snails. On the other hand, the opercular nuclei of the Caenogastropoda and Heterobranchia are often eroded away in adult individuals; even if present, the morphology of the nuclei does not seem to clearly reflect early ontogeny in those groups.}, author = {Kano, Yasunori} }