AGE, EXPERIENCE, AND THE RESPONSE OF STREAMSIDE SALAMANDER HATCHLINGSTO CHEMICAL CUES FROM PREDATORY SUNFISH

Previous work has shown that streamside salamander larvae (Ambystoma b arbouri; Ambystomatidae) exhibit an adaptive 'sink to the bottom' resp onse to chemical cues from predatory green sunfish (Lepomis cyanellus; Centrarchidae), that is, larvae sink to the bottom more quickly (thus minimizing exposure time to sunfish predation) when they are dropped into water with sunfish chemicals (as compared to fishless controls). Here, we examined this anti-predator behaviour in early hatchlings and the effects of age and experience on subsequent expression of this be haviour. Hatchlings responded significantly to fish chemical cues with in the first 18 h after hatching. Age did not significantly influence this response, i.e. regardless of age (1, 7, or 14 days after hatching ) larvae showed a significant response during their first exposure to fish chemical cues. Experience also did not significantly influence th e larval response to fish chemicals i. e., repeated exposures over 2 w eeks did not significantly influence the magnitude of the response. Fi nally, comparisons of 3 siblingships detected significant variation am ong siblingships that might reflect genetic variation in this behaviou r.