Митко Събчев; Людмила Станимирова [Mitko Subchev; Ljudmila Stanimirova]
31 December 1998 ·
volume 9 · pp. 5–18 ·
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Abstract: [no abstract available originally]
[Summary]: Sixty eight habitats (localities) containing crayfishes, Astacus astacus (Linnaeus, 1758), A. torrentium (Schrank, 1803) and A. leptodactylus Eschacholtz, 1823, were sampled during the period of 1977–1993. The collected crayfishes were examined for the presence of epibionts: Branchiobdella spp. (Annelida: Clitellata), Hystricosoma chappuisi Michaelsen, 1926 and Nitocrella divaricata (Chappuis, 1923) (Crustacea: Copepoda). The most abundant species of crayfish was A. torrentium which was found in 39 localities, followed by A. astacus — in 15, and A. leptodactylus — in 5. While the former two species live in sites up to an altitude of 1200-1600 m, A. leptodactylus was found only up to 100 m. The most abundant species of the genus Brachiobdella in Bulgaria are B. parasita, found in 40 localities, B. pentodonta — in 38, and B. hexadonta — in 31. The remaining three species,B. astaci, B. kozarovi and B. balcanica, were found in 14, 4, and 1, site, respectively. For the species found in more than 10 sites, no correlation between their distribution and the altitude was found. The gills epibionts, H. chappuisi and N. divaricata, were found in 18 and 19 localities, respectively, but their distribution in Bulgaria is probably wider than that because the crayfishes from the first collections were not examined for these two species. An earlier statement of Subchev (1987) about competition only between branchiobdellidans occupying the same microhabitat on the body of the crayfish, i.e. B. astaci and B. hexadonta, in the gills, and B. pentodonta, B. balcanica and B. kozarovi, on the anterior part of the host, has been confirmed.