The Appalachian Mountain of
eastern North America are considered to be a hotspot for Land Snail
biodiversity. There are currently at least ten described species of Polygyrid
Snails in the genus Triodopsis in
West Virginia alone, although there is considerable doubt about the validity of
some of these species. The species Triodopsis
juxtidens, Triodopsis discoidea, Triodopsis neglecta and Triodopsis pendula are currently
collectively known as the ‘Triodopsis
juxtidens subgroup’, though there are no clear morphological traits that
separate these species, while a recent genetic study which included several
specimens of Triodopsis juxtidens
strongly suggested that these were not all member of the same species, strongly
suggesting that the group is in need of revision.
In a paper published in the
journal Zootaxa on 29 January 2015, Kenneth Hotopp of Appalachian Conservation Biology describes a new and distinctive population of Triodopsis Snails from the Bluestone River Valley in Mercer and
Summers Counties, West Virginia. In the absence of a solid genetic or
morphological foundation for the classification of Triodopsis Snails he takes a conservative approach, and assigns
this population subspecies rank within the species Triodopsis juxtidens.
The new subspecies is named Triodopsis juxtidens robinae, in honour
of Hotopp’s wife Mary ‘Robin’ Robertson Gorrell, on the occasion of their 25th
wedding anniversary. The shells are 7.0-9.0 tall and 13.1-17.6 mm wide, have
4.75-5.5 whorls and are light or reddish brown in colour. The aperture of the
new population is roughly triangular in shape, as opposed to rounded as seen in
other specimens assigned to Triodopsis
juxtidens.
Specimen of Triodopsis juxtidens
robinae from Brush Creek in Mercer County, West Virginia. Charles Sturm in
Hotopp (2015).
See also…
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