Record of Ectocommensalism between Epistylis sp. (Peritrichia, Sessilida, Epistylidae) and Artificially Cultivated Narrow-Clawed Crayfish (Astacus leptodactylus Esch.)

A. ZAIKOV, Y. KARANIKOLOV and T. HUBENOVA-SIDEROVA

Institute of Freshwater Fisheries, BG-4003 Plovdiv, Bulgaria

Abstract

ZAIKOV, A., Y. KARANIKOLOV and T. HUBENOVA-SIDEROVA, 2000. Record of ectocommensalism between Epistylis sp. (Peritrichia, Sessilida, Epistylidae) and artificially cultivated narrow-clawed crayfish (Astacus leptodactylus Esch.). Bulg. J. Agric. Sci., 6: 575-578

The article deals with the first record of ectocommensal relationship between ciliata Epystilis sp. and artificially cultivated crayfish, observed in our country. Of the total of 830 female specimens observed, placed in individual hatching chambers, 510 were involved in ectocommensalism, the losses reported being 22%. It has been established that mass development of ectocommensalism under specific conditions might reflect negatively on crayfish survival.
Tests for Epistylis control were performed in baths with 10% NaCl solution of potassium permanganate KMnO₄ (1:1000) at different expositions. The best result was reported following treatment with potassium permanganate at exposition 120 s, which was tolerated well both by crayfish and the eggs and newly hatched larvae.

Key words: ectocommensal, Epistylis, Astacus leptodactylus, treatment