Biology ofSerranicotyle labracis, ectoparasite ofDicentrarchus labrax(Teleostei): contribution to the study of its populations
✍ Scribed by P. Silan; C. Maillard
- Publisher
- Springer-Verlag
- Year
- 1989
- Tongue
- English
- Weight
- 722 KB
- Volume
- 103
- Category
- Article
- ISSN
- 0025-3162
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✦ Synopsis
Serranicotyle labracis (Van Beneden and Hesse, 1863) Maillard, Euzet and Silan, 1988 (synonym: Microcotyle labracis Van Beneden and Hesse, 1863) is a monogenean Polyopisthocotylea and a gill parasite of the bass Dicentrarchus labrax (Linn6, 1758). Analysis of a western Mediterranean population of this parasite (Gulf of Lions, Languedoc, France) clarified several aspects of its biology. Its location in the gill biotope (Silan et al. 1987) was not fundamentally different from that found by Oliver (1977) and Winch (1983), but its distribution in host populations differed from that reported in the earlier studies; it displayed a negative binomial distribution in the study zone. At a finer level of observation, the behaviour of the hosts, as a function of degree of maturity and sex, appeared to determine more than any other factor the extent of infestation by the parasite. Previous suggestions in the literature to account for these differences in population dynamics are discussed. discussed, as are the various hypotheses which have been put forward.
Materials and methods
Sampling of hosts
The sea bass Dicentrarchus labrax used in this study were collected in 1983 from the Western Mediterranean (Gulf of Lions); 182 bass were captured by trawlers or with a draw net from the beach and in the Etang de Thau (a coastal lagoon in the H6rault department), using "capetchades" (fixed nets). The size categories in the samples are shown in Fig. 1. To ensure that no parasites and thus infrapopulation data (infrapopulation = all individuals of a species of parasite occurring in an individual host) were lost, the fish were collected alive and sacrificed only upon examination (within 24 h of capture).