Isopoda – parasites of the South Adriatic economically important fish species
Abstract
These researches were done on South Adriatic fish, and they included 15 fish species out of 7 families in total.
Five (5) Isopod parasites species from Cymothoidae family have been acertained (Nerocila orbignyi, N. maculata, Anilocra physodes, Meinertia oestroides and Emetha audouini) and 2 species belonging to Gnathiidae family (Gnathia sp 1 and sp 2). The first ones parasitize in adult form, the second ones in larval form (praniza larva).
Nerocila orbignyi, N. maculata, Anilocra physodes and Gnathia sp. 2 are fish surface parasites, Meinertia oestroides and Emetha audouini live in labial cavity, while Gnathia sp. 1 lives in the labial and gill cavities and on the gills.
A narrow parasite specificity is present with N. maculata (living only on Trisopteres minutus capelanus). A very wide parasite specificity is present with Gnathia sp. 1 and A. physodes, found on the representatives of 5 fish families.
Smaris vulgaris and Chelon labrosus are hosts to three parasite isopod species, the other fish only to one or two.
E. audouini, labial cavity parasite, shows a harmful influence to the conditional factor of its host, Smaris vulgaris. That harmful influence is more evident with smaller length classes than with the bigger ones. Invasion extensity is the greatest with the youngest individuals ranging from 86 - 100%. That is probably why the mortality is very high in the classes.
