Richard H. Backus

Carcharhinus floridanus, the Silky Shark, a Synonym of C. falciformis

Carcharhinus floridanus Bigelow, Schroeder, and Springer, 1943 (holotype a female about 2,300 mm long) and C. falciformis (Bibron 1841) (holotype a 528-mm embryo) represent the size extremes of a single species the name of which should be C. falciformis. This conclusion is based on the study of 65 specimens comprising both sexes and well distributed over the size range of the animal. The physical characters heretofore used to distinguish these nominal species, pectoral fin length, eye diameter, dorsal fin shape, contour of snout, and character of the denticles, all are shown to change gradually with growth from one supposed diagnostic set to the other. C. falciformis is sometimes confused with other carcharhinid sharks and means of distinguishing it from two of these, C. obscurus and Hypoprion signatus, are given.