''Helicina rhodostoma'' is a
species of
tropical land snail
A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial gastropod mollusks that have shells (those without shells are known as ...
with an
operculum, a
terrestrial gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
mollusk in the family
Helicinidae.
Shell description
Robert John Lechmere Guppy (1868)
[ Guppy R. J. L. (1868). "On the terrestrial mollusks of Dominica and Grenada, with an account of some new species from Trinidad". '' Annals and Magazine of Natural History'' (4)1]
429
442. noted that this species is not found above 1000 m altitude.
Three names have been used for this species, but material by Robinson et al. (2009)
shows that the forms
intergrade, illustrating the variability of the species. In general, populations from higher altitudes have a more pronounced columellar spine, and are more likely to have a red to reddish-orange
aperture, as seen in typical ''Helicina rhodostoma''.
Populations from drier, coastal areas tend to lack a columellar spine, and the aperture may be white or yellow.
Juvenile specimens of this species often have a hairy
periostracum
The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and ...
, which is gradually worn off as the snail reaches sexual maturity.
Distribution
''Helicina rhodostoma'' is endemic to the West Indian island of
Dominica
Dominica ( or ; Kalinago: ; french: Dominique; Dominican Creole French: ), officially the Commonwealth of Dominica, is an island country in the Caribbean. The capital, Roseau, is located on the western side of the island. It is geographically ...
.
Despite the fact that ''Helicina rhodostoma'' was originally erroneously described from Guadeloupe – and in subsequent reports from that island the error has been perpetuated – this species is undoubtedly a Dominican endemic.
It has not been found during subsequent surveys of
Guadeloupe
Guadeloupe (; ; gcf, label=Antillean Creole, Gwadloup, ) is an archipelago and overseas department and region of France in the Caribbean. It consists of six inhabited islands—Basse-Terre, Grande-Terre, Marie-Galante, La Désirade, and the ...
and
Marie-Galante.
The fact that no museum material exists labelled “Guadeloupe”, not even in the
Muséum national d'histoire naturelle in Paris, indicates that the species has never been collected on that island.
The synonymy of ''Helicina goldfussi'' and ''Helicina rhodostoma inermis'' is confirmed by
morphometrics and anatomical studies.
Ecology
''Helicina rhodostoma'' can be found living on trees, on
ferns, and also between rocks and gravel.
References
This article incorporates CC-BY-3.0 text from the reference.
[Robinson D. G., Hovestadt A., Fields A. & Breure A. S. H. (July 2009). "The land Mollusca of Dominica (Lesser Antilles), with notes on some enigmatic or rare species". ''Zoologische Mededelingen'' 83 http://www.zoologischemededelingen.nl/83/nr03/a13 ]
External links
* Richling I
The Land Snail Family Helicinidae www.helicina.de
{{DEFAULTSORT:Helicina Rhodostoma
Helicinidae
Endemic fauna of Dominica
Gastropods described in 1824
Taxa named by John Edward Gray