Intra-annual reproductive investments may not be predictive of male reproductive success because of the effects of intra- and intersexual interactions on sperm depletion. For long-lived iteroparous fish species such as lake sturgeon (Acipenser fulvescens), reproductive effort may affect lifetime reproductive success. Radio frequency identification antennas were placed at the mouth of the Upper Black River, Michigan, and downstream of spawning locations to quantify male migratory and mating behaviors, including upstream migration time (UT), river residence time (RT), number of intra-annual spawning migrations (IM), interannual spawning interval, and operational sex ratio during 2017–2018. Computer assisted sperm analysis was used to quantify sperm quality. RT had a strong negative influence on sperm concentration and with measures of sperm quality. RT and the number of females encountered were positively associated with male reproductive success (number of offspring sired) across years. RT, IM, and UT were negatively associated with sperm quality, indicating sperm depletion is a reliable measure of sexual activity. Results demonstrate trade-offs between benefits and costs associated with current reproductive effort on future reproduction.
Upstream migration and reproductive patterns of a population of allis shad in a small river (L'Aulne, Brittany, France)
