File:American malacological bulletin (1988) (18153072772).jpg

Title: American malacological bulletin
Identifier: americanmal6719881990amer (find matches)
Year: 1983 (1980s)
Authors: American Malacological Union
Subjects: Mollusks; Mollusks
Publisher: (Hattiesburg, Miss. ?) : (American Malacological Union)
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

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LYONS: WESTERN ATLANTIC CRASSINELLA 63
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Figs. 5-7. Left (upper) and right (lower) valves of three species of Crassinella from Florida. 5. C. dupliniana, height 2.8 mm, Hutchinson Island Station IV, July 1972. 6. C. lunulata, height 2.7 mm, Hutchinson Island Station II, January 1972. 7. C. martinicensis, height 2.7 mm, off Clear- water, Florida, depth 44 m. All specimens deposited in FDNR Marine Invertebrate Collection. Coan (1979). C. dupliniana (Fig. 5) is much smaller and has a more acute apical angle than C. lunulata and C. mactracea. The height of Dall's largest specimen of C. dupliniana was 3.2 mm and that of the largest specimen from Hutchinson Island was 3.4 mm, whereas maximum heights of C. lunulata and C. mactracea approach 10 mm (Allen, 1968). Valves of C. lunulata (Fig. 6) are quite compressed and have about 3 broad concentric ridges per millimeter of shell height, whereas valves of C. dupliniana are more swollen, and concentric ridges are finer and more closely spaced, averaging 6-7 per millimeter. C. martinicensis (Fig. 7), a species that occurs off both Florida coasts in 20-80 m depths, resembles the broad- ly triangular C. lunulata and C. mactracea more than it does the acute C. dupliniana. Harry (1966) reported a maximum height of 2.7 mm for C. martinicensis, but Florida specimens attain a maximum height of about 3.0 mm. Valves of C. mar- tinicensis have 4-5 concentric ridges per millimeter of height; the ridges often are spaced irregularly, and several secon- dary ridges sometimes occur between them. Crassinella dupliniana most resembles certain specimens of C. nuculiformis Berry, 1940, a narrowly ovate, inflated species that occurs from Baja California to Ecuador (Coan, 1979). The 2.9 mm valve of C. nuculiformis illustrated by Coan (1979: fig. 10) is strikingly similar to those of C. dupli- niana. Coan (1979) noted that C. nuculiformis attains a height of 6.4 mm, but specimens from the upper Gulf of California (including the specimen in his fig. 10) were smaller, general- ly < 3 mm. According to Coan (1984), C. nuculiformis is very similar to C. maldonadoensis (Pilsbry, 1897) from Uruguay to Argentina in the southwestern Atlantic, but the latter species has less prominent umbones and its concentric ribs fade more quickly toward the ventral margin. C. adamsi Olsson, 1961, an eastern Pacific species that attains a height of 3.6 mm, also is ovate but is proportionally longer than C. nuculiformis and C. dupliniana. Olsson (1961) mentioned an undescribed species similar to C. adamsi from the Caribbean coast of Panama. That species probably is C. aduncata, which differs from C. adamsi "in attaining a larger size, having a more abrupt posterior slope, and . . . more prominent concentric ribs" (Coan, 1984: 165). In addition to the Hutchinson Island material, I have examined specimens of Crassinella dupliniana from off Cape Canaveral, Florida, from the Gulf of Mexico off western Florida (both FDNR Marine Invertebrate Collection), and from beach drift at Hunting Island State Park, South Carolina. These records indicate that C. dupliniana probably lives among ap- propriate sediments throughout much of the warm-temperate Carolinian Province.

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