We have conducted a survey of toxicity distribution with depth of common marine sponges of the Southern province of New Caledonia. Test fish #Gambusia affinis$ (#Vertebrata, Pisces$) were exposed to aqueous macerates from 30 shallow water and 30 deep water sponges. Mortality counts and relative toxicites as evidenced through gradual behavioural changes were recorded against a geometric time scale. The responses exhibited by the fish ranged from rapid mortality and varying levels of distress or narcotization to effects undistinguishable from controls. Sponges exhibiting similar behavioural patterns (from 8 computer-defined pattens) were classified into 6 toxicity groups falling into 3 broad categories : 100 % lethal, harmful to toxic, and non-toxic. Eighty percent of the sponges were at least harmful to toxic, deep sponges being generally more lethal. Overall toxicities being comparable, most sponges bear morphological defences as well, though deep sponges rely on different structures tha shallow species. (Résumé d'auteur)
