Variation in Growth and Survival of Hyla gratiosa Larvae in Experimental Enclosures

Abstract

Larvae from seven full sib families of Hyla gratiosa were reared in experimental enclosures in a natural pond, while additional larvae from those families were raised in the laboratory. The sibships displayed different average levels of survival in the enclosures. The level of survival in an enclosure was positively correlated with the average body size of the enclosed larvae, and this size varied significantly among sibships in concordance with the variation in survival. Significant differences were found among sibships in the body sizes of larvae grown in the laboratory. Survival also varied significantly among the sibships in the laboratory, but was uncorrelated with either field survival or laboratory growth. Relative growth differences among sibships were consistent between laboratory and field conditions, although the extent of such variation was increased under field conditions. The positive correlation between average size and survival in the enclosures was interpreted as the result of size-limited predation by insects. Variation in growth among laboratory-reared sibships was interpreted to be a conservative assay for phenotypic variability under field conditions.