Effects of a bioactive diatom-derived aldehyde on developmental stability in Nereis virens (Sars) larvae: an analysis using fluctuating asymmetry

Abstract

Fluctuating asymmetry (FA) is regularly used as an indicator of individual or population fitness and can provide a useful measure of environmental stress. Here the validity of FA as a measure of larval fitness in the polychaete Nereis virens, and hence its value in ecotoxicological bioassays, was determined via a series of laboratory experiments. FA measurements were taken from two or three morphological traits at the nechtochaete larval stage from a number of larval batches with different fertilization dates. Post-fertilization survival for each batch was also measured. Regression analysis revealed a significant negative correlation between the FA index for each batch and percentage survival. The diatom-derived aldehyde 2- trans,4- trans decadienal (DD) is known to disrupt fertilization and early development in N. virens and other marine invertebrates. Here FA is applied to quantify the chronic/sub-lethal effects of DD exposure on post-embryonic development to the nechtochaete stage. Trait size, development rate and FA were all significantly affected by increasing concentrations of DD. This provides further evidence for the teratogenic effects of DD on larval development. It can be concluded from these experiments that FA can be a useful tool for sensitive monitoring of chronic environmental stress and sub-lethal effects of toxins in N. virens larvae, and could provide a useful tool for invertebrate larval ecotoxicology studies.