Markers identified for metamorphosis in halibut
Flatfish such as halibut, turbot and sole play an important role in the diversification of European aquaculture. However, production has faced problems with the successful rearing of larvae. One such challenge involves failed metamorphosis. Metamorphosis in flatfish is associated with the change from a free-swimming symmetrical larva to an asymmetric bottom-living juvenile. Another feature of metamorphosis is that one eye migrates from one side of the head to the other. The AARDE project identified reliable markers which acted as indicators of the progression of metamorphosis in Atlantic halibut. Furthermore, the markers were able to differentiate between different stages in the life cycle and between normal and abnormal metamorphosis. Both molecular and morphological markers were identified, which changed between pre-metamorphic larvae and post-metamorphic juveniles. Although the markers were developed for Atlantic Halibut in particular, it is intended that they should be applied to flatfish in general. However, this will require further testing. Markers for diagnosing abnormal metamorphosis were difficult to find and need further validation. The creation of a tool for improving the quality, health and predictability of fish larval production is extremely valuable to the aquaculture industry. It helps in the sustainable production of high quality fish for the consumer and in providing jobs in remote rural areas which have only limited employment.
