A DESCRIPTION OF SPAWNING BEHAVIOR OF CAPTIVE DOVER SOLE, SOLEA-SOLEA (L)

Video recordings were made of captive sole (Solea solea (L.)) spawning in a 1 m deep, 3 m diameter tank. Fish were recorded swimming in pairs. During four nights six separate pairings were observed, all within 3 h of the main lights being turned off. Pairs formed on the tank floor by the male swimming into a position under a female where their genital pores were close. They then swam together towards the water surface with closely synchronised body movements. They remained together for up to 70 s, while maintaining a head-up position just beneath the surface. Egg release itself could not be identified from the recordings, but on each occasion fertilized eggs were found in the tank on the following morning. This behaviour is compared to other accounts of flatfish spawning and discussed in relation to observations of sole seen swimming at the surface of the North Sea.