Instar determination, length-mass and length-length relationships for the larvae of Chaoborus punctipennis Say from a southeastern (USA) cooling reservoir

Abstract

Instar determination, length-mass and length-length relationships for Chaoborus punctipennis Say lar vae from a southeastern (USA) reservoir are described. Only head capsule length proved useful in determining instar stage. Power functions best fit length-length relationships among head capsule length, thorax width and body length. Power functions of body length, total length and thorax width were the best predictors of larval dry and ash-free dry mass. Thorax width may be a more reliable predictor of mass since it is not influenced by curvature of the body as body-length measurements may be. Summary statistics for head and body dimensions and length-mass regressions from this study were comparable to data in the literature for C. punctipennis.