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Euconulus chersinus (Say, 1821) Wild Hive |
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2.9 mm. |
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| Collected from wrack (small sticks and debris) along Sunfish Creek, Bardstown, Nelson Co., Kentucky, 8/18/2013; specimen received a light application of oil to limit static electricity. Digital image by Lori Schroeder |
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| There are two specimens of this species figured above. The glossy shell (L and R; 2.9 mm in actual height; 7.8 whorls) was dead-collected in drift along a creek in Nelson Co., Kentucky by Lori Schroeder. The shell in the center is 2.45 mm high (6.8 whorls) and was live-collected in Duval Co., Florida. While there is clearly some post-mortem buffing of the Kentucky specimen, the more interesting contrast involves the middle vs. the L image and middle vs. the R. The L image was adjusted to be the same height as the reference Florida specimen while the R image is to scale vs. the Florida one. While the L pair look quite different in profile, this is an artifact of scaling. Because of allometric growth (increasing translation, causing a reduction of the spire angle with enlargement of the shell), specimens of this, and other Euconulus species, become more narrow in profile as they grow. When one mentally subtracts the last whorl of the R specimen, the remainder of the shell is essentially superimposable on the center shell. When this pattern of changing morphology isn't accounted for, the identification of eastern US Euconulus species, enough of a challenge anyway, becomes even more difficult. Any figure lacking an indication of specimen size, especially of a younger shell, is of limited taxonomic use. |
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