MITOCHONDRIAL-DNA VARIATION OF CHAMPSOCEPHALUS-GUNNARI LONNBERG (PISCES, CHANNICHTHYIDAE) STOCKS ON THE KERGUELEN PLATEAU, SOUTHERN INDIAN-OCEAN

The distribution of the icefish Champsocephalus gunnari on the Kerguel en Plateau is confined to the inner shelves of Heard and Kerguelen isl ands and outlying banks where the water depth is less than 350 m. For fisheries management purposes, it is necessary to know whether fish fr om the various shelves and banks belong to one single or several separ ate populations. Analysis of the mitochondrial DNA of fish from variou s localities using restriction endonuclease enzymes revealed no signif icant genetic heterogeneity between any of the localities. This does n ot preclude the existence of isolated stocks at the present time but i ndicates that the populations have been separated too recently for gen etic isolation to be manifested, or that low-level interchange of fish between the populations may be maintaining genetic homogeneity.