THE DEVELOPMENT OF SCHOOLING BEHAVIOR IN ATLANTIC HERRING CLUPEA-HARENGUS

The timing of the development of schooling behaviour in Atlantic herri ng Clupea harengus and the quantitative and qualitative evolution of s uch behaviour in the larval and post-metamorphic stages were investiga ted with a simulation model and experimental observations of laborator y-reared fish. Herring larvae started to develop schooling behaviour b etween the lengths of 35 and 40 mm. This coincided with the beginning of metamorphosis, characterized by ontogenetic changes which require a switch to a different antipredator strategy from that employed by ear ly larvae, white providing the sensory and anatomical mechanisms neces sary for the formation of schools. Schooling behaviour was established at the end of metamorphosis (50-55 mm) and its characteristics contin ued to evolve throughout the early juvenile stage. A critical period i n terms of vulnerability to predation is expected between the end of t he larval and beginning of the juvenile stages, before schooling behav iour is fully developed. The implications of some of the results for t he methodology of future studies are also discussed.