Notes on the Distribution of Hyalophysa and Gymnodinioides on Crustacean Hosts in Coastal North Carolina and a Description of Hyalophysa trageri sp. n.

Abstract

SYNOPSIS. Hyalophysa chattoni Bradbury, Hyalophysa Iwoffi Bradbury & Clamp, and Gymnodinioides inkystans Minkiewicz are found on species of palaemonids, astacurans, grapsid crabs, ocypodids, anomurans, and portunids in coastal North Carolina. Hyalophysa trageri sp. n. is described from species of Uca and Sesarma. Its life cycle is like that of other exuviotrophic apostomes. Hyalophysa trageri differs from other species in the genus in the pattern of its infraciliature and the shape of the macronucleus during the trophont stage.In coastal North Carolina, H. chattoni is euryhaline and infests a great number of species. Hyalophysa Iwoffi is found in many locations on the freshwater shrimp Palaemonetes paludosus (Gibbes), and in one location on the crayfish Cambarus sp. Hyalophysa trageri is the most limited in range, being found only on semiterrestrial crabs. On some host species G. inkystans is found alone, but is sympatric with Hyalophysa on others.Possible factors restricting the distribution of these apostomes are discussed. These include the structure of their encysted stages, salinity, and the behavior of their hosts.