Exuviotrophic apostome ciliates from freshwater decapods in southern Alabama (USA) and a description of Hyalophysa clampi n. sp. (Ciliophora, Apostomatida).

Apostome ciliates from crayfish and freshwater shrimp in southern and central Alabama were surveyed in this study. Hyalophysa bradburyae was found on both crayfish and shrimp from 16 sites in eight drainages. A new species, Hyalophysa clampi n. sp., was found infesting crayfish at one site and simultaneously infesting crayfish with H. bradburyae at two sites. Characteristics of the trophont ciliature of H. clampi n. sp. separate it from other species in the genus. Particularly, the contractile vacuole pore is oriented posterior to the ventral kineties xyz, kineties 1 and 2 are undivided, an apparent second contractile vacuole pore is present between the ventral portions of kineties 1 and 2, the anterior ventral field is tightly arranged, and there is an apical field of kineties between kineties 4 through 6. This report expands the known range and diversity of the genus Hyalophysa in the state of Alabama.