The Protozoan Associates of some Crustaceans

Abstract

Protozoan associates found on the estuarine shrimp Metapenaeus monoceros (Fabricius) and the tanaidacean Apseudes chilkensis (Chilton) from Cochin backwaters have been described. A peritrich ciliate Zoothamnium rigidum (Precht.), a heterotrich Stentor coeruleus Ehrenberg and a microsporidian were recorded in both the hosts. Another ciliate Lagenophrys cochinensis (Santhakumari and Nair) was noticed only in A. chilkensis. Experimental infestation of Z. rigidum on shrimp and the effect of stress produced by high turbidity and low oxygen tension in the infested tanaidacean were carried out. Most of the infested tanaidaceans were found dead, showing the potentially harmful nature of this ciliate