Egg characteristics and larval growth of bluegill from stunted and non-stunted populations

Abstract

Many bluegill (Lepomis macrochirus) populations are characterized by a stunted adult size structure and consist primarily of individuals that mature at a relatively young age and small size. Little is known about maternal effects in bluegill populations and whether they may explain the occurrence of stunted growth. We spawned bluegill from both stunted and non-stunted populations in experimental tanks and collected eggs and larvae from each clutch. We determined whether differences in egg and oil globule diameter and larval growth existed between eggs collected from females from each population. Egg and oil globule diameter were not related to female length and did not differ between stunted and non-stunted populations. Larvae length after 21 d was positively related to egg diameter but was not related to either female length or oil globule diameter. Consequently, egg diameter had a greater influence on larval growth than female source population or size. No differences were observed between source populations indicating that some aspects of early life history are more heavily influenced by egg properties than adult life history differences between parental source populations.