Argopecten irradians taylorae Petuch, 1987
PETUCH, E. J. 1987. New Caribbean Molluscan Faunas. The Coastal Education & Research Foundation Inc. 154 pp. [p. 32, pl. 5, figs. 10, 11]
«Argopecten irradians taylorae new subspecies (Plate 5, Figures 10, 11)
Material Examined: HOLOTYPE - Length 45 mm, width 46 mm, collected from try net trawling, from 10 ft. depth, on solid Turtle Grass (Thalassia testudinum) bottom, in Rabbit Key Basin, Florida Bay, Florida Keys, 1983, USNM 859901; PARATYPES - 8 specimens, lengths 43-28 mm, same depth, locality, and date as holotype, USNM 859902; 7 specimens, same locality, depth, and date as holotype, Petuch collection; 5 specimens, same locality as holotype, Sunderland collection.
Description: SheII thin, fragile, moderately inflated, with lower valve slightly more convex than upper valve; ribs square in cross-section in small juveniles, rapidly becoming wider and flatter as shell matures; mature specimens with very flattened, close-packed ribs; rib count ranging from 23- 25 (holotype with 23); color of upper valve composed of mottled streaks and patches of dark brown, pink yellow, and white on khaki green and gray background; some specimens with 3-5 white or yellow rays; bottom valve yellow or yellow-white, copiously covered with brown and white mottlings and flammules; in some specimens, entire bottom valve is darkly colored with brown mottlings; auricles of some specimens marked with brown and white zebra-like flammules. Etymology: Narmed for Ms. Linda Taylor of Ft. Lauderdale, Florida. Discussion: Prior to the discovery of this isolated subspecies, there were no known populations of Argopecten irradians found in the Florida Keys area and southern tip of Florida (ABBOTT, 1974, pp. 447-448). There are now four known Iiving subspecies of Argopecten irradians: A. irradians irradians (Lamarck), which ranges from Cape Cod to New Jersey; A. irradians concentricus (Say), which has a split range with an eastern population ranging from New Jersey to Georgia, and western population in the Gulf of Mexico, ranging from Tampa, Florida to Louisiana; A. irradians taylorae Petuch, which is restricted to Florida Bay (Everglades National Park) and the western sides of the middle and upper Florida Keys; and A. irradians amplicostatus Dall, which ranges from central Texas south to the eastern coast of Central America. An extinct subspecies, A. irradians sablensis Clarke, was described from Holocene fossils from Nova Scotia. Argopecten irradians taylorae is restricted to the dense, well developed Turtle Grass (Thalassia testudinum) beds that virtually carpet most of the shallow Florida Bay west of the Florida Keys. Here, it is an abundant animal, often occurring in large shoals. Argopecten irradians taylorae differs from A. irradians concentricus, its closest relative, in being a much smaller, more fragile shell, by having more ribs (23-25 as opposed to 19-21), by having ribs that are flat in cross-section as opposed to square, by having wider, more flaring ribs, and by being a much more colorful shell, with rays and mottlings of pink brown, yellow, white, khaki, and gray. In being such a colorful, attractive small scallop, most local collectors had misidentified this subspecies as Argopecten nucleus (Born). The bottom valve of Argopecten irradians taylorae is generally yellow instead of white, as in the other subspecies, and tends to have more brown mottlings than A. irradians concentricus. Fossil specimens of A. irradians taylorae are common in Pleistocene formations in the Everglades region of southern Florida.» EDWARD JAMES PETUCH, 1987
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E. J. Petuch, 1987, plate 5.
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