Use of copepods in Ballan wrasse larvae production

Offentlig prosjektsammendrag

Ballan wrasse is one of the most promising farmed cleanerfish species used to control sealice infestations in Norwegian salmon farms. The wild catch of wrasse is limited and industrial production is the only way to provide the required numbers of Ballan wrasse. However, the production of wrasse is challenging, partly due to an extremely small larvae which is little developed at hatching. As with many other marine fish species, the larvae require live feed. Rotifers are usually cultivated at hatcheries, providing the first feed for wrasse larvae. However, the use of copepod nauplii is proven superior to rotifers during first feeding of marine fish larvae. In later years an industry able to deliver stable and high quantities of nauplii to be used in first feeding of marine larvae has developed. In this project nauplii produced by C-Feed will be used to feed Ballan wrasse at first feeding, followed by crustacean nauplii (produced by Planktonic, Trondheim) around two weeks post hatching. Thereby, we will be able to omit both rotifers and Artemia during first feeding. Increased survival and growth of the larvae are expected. The wrasse will be kept after weaning, enabling us to examine the effect of early larval feeding on quality, development, growth and survival through the juvenile phase.