A Revision of Mastus carneolus (Mousson 1863) from Istanbul, Turkey (Gastropoda: Pulmonata:
Enidae)
Örstan,
A., Schriften zur Malakozoologie 17:65-70, 2001.
This summary by
Aydin Örstan
Mastus is a common genus of land snails usually
found among calcareous rocks in Turkey and Greece. The differences between the shells
and anatomies of most species are slight. Expectedly, these characteristics
result in taxonomic difficulties and confusion. At the same time, the same
characteristics make the genus a good subject for studies on speciation and
zoogeography.
Left: Four
specimens of Mastus carneolus (Mousson 1863) from one location in Istanbul. The first
three shells show the range of variation in the shape of the angular tooth,
which the fourth shell lacks. Right: Mastus etuberculatus (Frauenfeld
1867) from northwest of Göcek and Mastus rossmaessleri (Pfeiffer 1847)
from northeast of Kuşadası (both towns are in western Turkey). Scale
bars are in millimeters.
This study is about Mastus carneolus, the
only Mastus species of the Istanbul area. Past authors divided this
species into two subspecies: the larger Mastus carneolus carneolus (Mousson 1863) and
the smaller M. carneolus subcarneolus (Bourguignat
1876) with the height boundary between
them being 10 or 11 mm depending on the author. I collected the specimens used
in this study in the summer of 2000 at several locations in mainland Istanbul
and on Büyükada and Heybeliada, two islands off Istanbul. (To read an account
of my collecting trips on these islands click here.)
I found specimens covering the previously published height ranges for both
subspecies coexisting in two populations: one on the mainland Istanbul and the
other one on the island of Büyükada. Statistical analyses of shell measurements
of these populations indicated that they consisted of single genetic entities.
Furthermore, two specimens were collected on Heybeliada, the type location of M.
carneolus subcarneolus. Both were longer than 10 mm and one was longer than
11 mm. Altogether, these results found no conchological support for the division
of M. carneolus into subspecies.
I based some of my
arguments on those of Francisco Welter-Schultes in his two papers on the Mastus
of the islands Crete and Gavdopoula. For more information, consult his papers
cited below.
LITERATURE
WELTER-SCHULTES, F.
W. (1999). The land snails of the threatened island of Gavdopoula, with
description of an endemic Mastus species (Gastropoda: Enidae). Biologia
Gallo-hellenica, 25:91-104.
WELTER-SCHULTES, F.
W. (2000). Spatial analysis of shell parameters suggests low species number of Mastus
(Gastropoda: Pulmonata: Enidae) in central and eastern Crete. Folia
Malacologica, 8:151-160.
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