Trait canalization analysis of water quality, temperature, and developmental associations with early life stages of two fish species.

Abstract

Evaluation of trait robustness based on environmental fluctuation in ontogenetic life stages are needed to evaluate stability and trait response during critical developmental events. Hardness, alkalinity, acidity, light intensity, and thermal differences were studied for trait canalization variation in morphometric, meristic, ontogenetic processes, and pigment characteristics. Trait canalization was observed with no statistical differences (p>0.05) in mixed random two-way ANOVA comparisons between various block and treatment effects for hardness, alkalinity or acidity. Thermal block variation differences in six measures, including mandible length, yolk sac length, midpostanal depth, and head width, incubation, and hatching length, varied significantly (p≤0.05) with declining temperatures. Water quality and thermal attributes exhibited trait canalization and did not increase character state variation in the early life stage morphological expression, which result in stable phenotypic inheritance rather than variable environmental conditions during embryonic and larval development.