Blanfordia

''Blanfordia'' is a genus of terrestrial gastropod mollusks in the family Pomatiopsidae. They are land snails which have an operculum.

The generic name ''Blanfordia'' is in honor of English naturalist William Thomas Blanford.

Distribution

The genus ''Blanfordia'' is endemic to Japan.Kameda Y. & Kato M. (2011). "Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago". '' BMC Evolutionary Biology'' 11: 118. . ''Blanfordia'' species live on Honshu and on Hokkaido.

''Blanfodia'' and '' Fukuia'' are the only two genera of Pomatiopsidae that are endemic to Japan. They occur especially in the northern and western part of Japan on the coast of the Sea of Japan. There is a unique climate in the Sea of Japan with high precipitation as snowfall during the winter in the area of distribution of ''Blanfordia''. Such species, unique to the region near the Sea of Japan, are known as "Japan Sea elements".

Description

Some species of ''Blanfordia'' have a shell with varix.

''Blanfordia'' has short stubby triangular tentacles. Short tentacles is derived character, while long tentacles is a primitive character (a plesiomorphic trait) within the Littorinimorpha.Barker G. M. (2001). ''Gastropods on Land: Phylogeny, Diversity and Adaptive Morphology''. In" Barker G. M. (ed.)
The biology of terrestrial molluscs
'. CABI Publishing, Oxon, UK, 2001, . 1-146, page 37. Eyes are at the base of tentacles. According to Nelson Annandale the snout is narrow and long. Annandale N. (1924). "The molluscan hosts of the human blood fluke in China and Japan and species liable to be confused with them". In: Faust E. C. & Meleney H. E. "Studies on schistosomiasis japonica". ''American Journal of Hygiene'' Mon. Ser. no. 3: 269-294. plate 36. text figures 1-6.
abstract
- Also cited by Bartsch (1936) on th
page 7

There are lobes on each side of the frontal part of the foot and there is also a lobe with operculum on the foot. There is a groove on the foot dividing the foot into frontal and back part. While moving, it will put the tip of its snout on the ground and then it will drag itself while it is moving each part of the foot separately like a leech.

Gill filaments ( ctenidium) are reduced in all species of ''Blanfordia''. There is a verge with a massive gland in some species of ''Blanfordia''. The nervous system of ''Blanfordia'' is concentrated.

Reproductive system: the bursa copulatrix is partly surrounded by albumen gland (posterior pallial oviduct). Albumen gland and spermathecal duct have a common opening. Sperm duct and also spermathecal duct emerges from mid-ventral part of the bursa copulatrix.

Paul Bartsch (1936) Bartsch P. (1936). "Molluscan intermediate hosts of the Asiatic blood fluke, ''Schistosoma japonicum'', and species confused with them". ''Smithsonian Miscellaneous Collections'' 95(5)
1
60. provided nomenclatural review of the genus ''Blanfordia'' with detailed description of its species.

Comparison of apertural views of shells (the scale is 1 mm):

Species

Species within the genus ''Blanfordia'' include:
*'' Blanfordia bensoni'' (Adams, 1861) - type species.Davis G. M. (1979). "The origin and evolution of the gastropod family Pomatiopsidae, with emphasis on the Mekong river Triculinae". ''Academy of natural Sciences of Philadelphia'', Monograph 20: 1-120
at Google books
The type species was subsequently designated by Geoffrey Nevill (1878). Nevill G. (1878). ''Hand list of Mollusca in the Indian Museum, Calcutta. Part I. Gastropoda.'' Calcutta. Printed by order of the Trustees. 338 pp
page 254

*'' Blanfordia japonica'' (Adams, 1861)
*'' Blanfordia simplex'' Pilsbry, 1902

"''Fukuia''" ''ooyagii'' is the most closely related species to ''Blanfordia'' according to the molecular phylogeny analysis, but its generic assignment should be determined coupled with the investigation of its soft-part morphology.

The speciation of genus ''Blanfordia'' likely started around 6.4 million years ago in the Late Miocene, while the divergence between ''Blanfordia'' and "''Fukuia''" ''ooyagii'' is estimated to be around 17.4 million years ago in Early Miocene.

Synonyms:
*''Blanfordia integra'' Pilsbry, 1924 is a synonym of '' Fukuia integra'' (Pilsbry, 1924). According to the molecular analyses of 18S ribosomal RNA, 28S ribosomal RNA, 16S ribosomal RNA, and cytochrome-c oxidase I (COI) genes by Kameda & Kato (2011) noted that ''Blanfordia integra'' is undoubtedly a member of the genus ''Fukuia''. As early as 1979, Davis hypothetized that ''Blanfordia'' and ''Fukuia'' are either the same genus or that they may have a common ancestor.

Cladogram

A cladogram showing phylogenic relations of genera within Pomatiopsidae:

Ecology

''Blanfordia'' and ''Fukuia'' (that contain terrestrial '' Fukuia integra'') are the only genera of terrestrial gastropods within the family Pomatiopsidae, which otherwise consists of mainly freshwater (but also seasonally amphibious) snails. Species of ''Blanfordia'' can be found from the sea coast to the mountains. They live in coastal dunes and littoral forests ('' Blanfordia simplex''), from coastal to inland forests ('' Blanfordia japonica'') and on the forest floor of inland forests ('' Blanfordia bensoni''). Other land snails living in habitats of ''Blanfordia'' snails include for example diplommatinids, camaenids and bradybaenids.

The phylogenetic analyses by Kameda & Kato (2011) indicates that Japanese Pomatiopsinae have adapted from freshwater environment to terrestrial life ( terrestrialization) at least twice (three ''Blanfordia'' species in one clade and '' Fukuia integra'' - formerly ''Blanfordia intergra'' species in another clade). This change has happened in regions with heavy snowfalls that face the Sea of Japan.

References

External links

* 安藤 保二 & 波部 忠重 ndo Y. & Habe T.(1983). "陸産貝類図説 (4) : イツマデガイ属 ''Blanfordia'' Adams llustrated Catalogue of Land Snails (4): Genus ''Blanfordia''. ''ちりぼたん Newsletter of the Malacological Society of Japan'' 14(1): 9-12
CiNii

{{Taxonbar, from=Q4925082

Pomatiopsidae