ALTERNATIVE LIFE-HISTORY STRATEGIES OF CATFISHES

Siluriformes, as well as Characiformes and Cypriniformes, are a divers e and widespread group of Ostariophysan fishes, but Siluriformes have a probable ancestral benthic feeding habit. They have a unique suite o f morphological, physiological, ecological and behavioural traits that equip them to succeed in freshwaters but only to a limited extent in the sea. They are typically, non-aggressive stalking predators that hu nt at night or in turbid water using primarily nonvisual sense organs, although there are many exceptions. The modification of the Weberian apparatus for sound production has probably resulted in some loss of b uoyancy control. Catfishes are represented in all the different breedi ng guild categories and exhibit diverse and sometimes bizarre breeding methods. Catfishes tend towards the altricial end of the altricial-pr ecocial life-history continuum. Only two families (Ariidae and Plotosi dae) have successfully colonised the sea; physiological constraints an d strong competition from Elasmobranchii and Actinopterygii fishes are probable reasons, and it is notable that the two families that have s ucceeded have precocial life histories that are more suited to highly competitive environments.