Reappraisal of the use of parasites for fish stock identification

Abstract

Analysis of the geographical distributions of parasites is an excellent source of information about the movement of host fish. Occasionally such analysis can also allow us to discriminate between fish populations, though unequivocal discrimination usually requires methods with a genetic basis. In assessing fish movement, parasites have two advantages over conventional tags: they can more readily detect mass migration and, because the fish only have to be caught once, the data are usually cheaper to obtain. The most important criterion in selecting a parasite to be used as a tag is its longevity in the fish; short-lived parasites give information on short-term movements of the fish, long-lived parasites on more extensive migrations.

Metazoan parasites of the lesser-spotted dogfish Scyliorhinus canicula and their potential as stock discrimination tools

“…A combination of both parasite and tagging data is a powerful complementary tool in evaluating the movements of ¢sh (Lester et al, 1988;Lester, 1990). Scyliorhinus canicula seems well suited to such a study.…”

“…The aim of the present study was to identify those species of parasite that will be suitable as markers. Lester (1990), Williams et al (1992) and MacKenzie & Abaunza (1998) list established criteria for the selection of tag species.…”

Insular stock identification of <EM>Serranus atricauda</EM> (Pisces: Serranidae) through the presence of <EM>Ceratothoa steindachneri</EM> (Isopoda, Cymothoidae) and <EM>Pentacapsula cutanea</EM> (Myxozoa, Pentacapsulidae) in the Canary Islands

“…The application of these methods depends on simplicity, number of samples and, in a general context, the cost-effectiveness of the results obtained. Parasites are thus considered as biological tags (Kennedy, 1979;Chenoweth et al, 1986;Leaman and Kabata, 1987;Lester, 1990;Dalton, 1991;MacKenzie and Longshaw, 1995;Grutter, 1998) and the analysis of their geographical distributions is an excellent source of information on the movements of the host fish species (Campbell et al, 1980;Wichowski, 1990;Carbonell et al, 1999). Although such an analysis may allow us to discriminate between distinct fish populations or stocks, the unequivocal discrimination usually requires methods based on genetics.…”

Parasites of the American White Pelican

“…For example, digeneans (Bartoli 1989) have indicated host diets, prey preference, habitat where prey was eaten, and host migration, even though digeneans and other parasites of fishes have been used more often than those of birds as well as used for additional categories of biological indications (e.g., Kabata 1963, Margolis 1963, MacKenzie 1983, Lester 1990, Overstreet 1993. These articles cite criteria one should meet, which vary considerably, depending on the type of question the biological indicator should answer.…”