A disease whose severity seems directly bound to conditions of cultivation can cause a heavy mortality in the common prawn Palaemon serratus (Pennant) at molting. The causative agent, A. rodor, is a ciliate, a common external parasite whose life cycle is adapted to the molting cycle of the shrimp. The principal factors favorable to the development of the parasite were studied: age of the host, water temp, numbers of shrimps as a function of the quantity of water and its renewal. The sp A. rodor, although related to the Conidophryidae, Kirby, 1941 (1936) has significant differences (1) in its ethology (it feeds on the exoskeleton without penetrating to its hosts' tissues), (2) in its vegetative multiplication (tomitogenesis combines the cortical... |