Use of mesocosms in larval rearing of saithe [ Pollachius virens (L.)], goldsinny [ Ctenolabrus rupestris (L.)], and corkwing [ Crenilabrus melops (L.)

Abstract

Pilot experiments were carried out in mesocosms (5.3 m 3 plastic bag enclosures) for larval rearing of the commercially important saithe [ Pollachius virens (L.)], and two wrasse species, goldsinny [ Ctenolabrus rupestris (L.)] and corkwing [ Crenilabrus melops (L.)] which are both used as cleaner-fishes for control of sea-lice infestations in Atlantic salmon farming. Fertilized saithe eggs were collected from natural spawning in a simple and inexpensive tank system. Goldsinny and corkwing eggs were obtained by stripping mature individuals collected from the sea. Egg mortality during incubation was low in all species. Larvae were released in the rearing enclosures a few days after hatching and fed natural plankton (mainly copepod nauplii). Survival through metamorphosis was low for saithe (3%), which may be attributed to specific environmental requirements, in terms of water quality, in this species. Survival in the wrasse was good (20–40%), indicating that the use of mesocosms may have potential for mass-production of these species.