Role of bay, fjord and seamount on the early life history of Lepidonotothen squamifrons from the Kerguelen Islands

Abstract

Among the Kerguelen Islands' demersal fish, larvae of Lepidonotothen squamifrons are dominant during the summer over the island shelf and surrounding seamounts. Distribution of larval stages from different scientific surveys confirmed the position of the two known spawning grounds (south of the Kerguelen shelf and at the Kerguelen-Heard bank) and may indicate other spawnings on the Skiff bank and in bays and fjords. Different larval cohorts were observed for the shelf and the coastal zone whereas a unique one was observed for Skiff and Kerguelen-Heard seamounts. Larvae from the spawning ground south of the Kerguelen shelf appear in early summer and show a northwards dispersal to the northeastern nearshore zone, the Baleiniers Gulf, following the scheme of fish migration shown by Harden-Jones. Later on, larvae from the northern inshore spawning zone occur in the same area, which presumably then avoid intraspecific competition with the previous larvae. Larval distribution and migration strategy seemed to be in accordance with the island mass or seamount effect under a regular current.