Brachycoelium ambystomae sp.n. (Trematoda: Brachycoeliidae) from Ambystoma opacum.

Brachycoelium ambystomae sp. n. is described from the marbled salamander, Ambystoma opacum (Gravenhorst), from Leon County, Florida. This species differs chiefly from the 11 other described members of the genus by its spination, distribution and development of vitellaria, position and size of its ovary and testes, and body length. Specimens of the genus Desmognathus from the same locality were not infected with this trematode. Nine marbled salamanders, Ambystoma opacum (Gravenhorst), collected in Leon County, Florida, in November 1961, harbored trematodes of the genus Brachycoelium. Byrd (1937) reported the possibility that 13 well defined species were included in this genus. Rankin (1938) reduced all 14 described species to synonymy with the type species, Brachycoelium salamandrae (Frolich, 1789). Parker (1941) and Cheng (1958), after careful studies, agreed that specimens which they collected possessed diagnostic characters of some particular species and not of others. Cheng (1958) and Cheng and Chase (1961) reported that there were enough distinct characters, e.g., shape and position of testes and distribution of vitellaria, to recognize 11 species in the genus Brachycoelium. Careful study of the specimens from northwest Florida indicated that on the basis of their extensive spination, development and distribution of vitellaria, size of testes and ovary, and body length, they represent a new species, here designated as Brachycoelium ambystomae.