Life-history Plasticity Among Stream Sites in the Chattahoochee River Drainage, Alabama

Abstract

Abstract Cyprinella venusta (Blacktail Shiner) were studied at four sites to investigate life-history parameter variation in Alabama streams. Consistent with life-history theory, fish from a perceived degraded site were significantly smaller than fish from sites that had less apparent environmental disturbance. Fish from the degraded site had the smallest size at maturity and the smallest propagule size. Egg diameters were not related to standard length of fish among sites. There was no significant difference in mature egg diameters; however, ripening egg diameters differed among sites. Clutch sizes adjusted for standard length varied among sites. There was no difference in gonad mass in females for all spawning months; however, there were differences in gonad mass in males in July. The gonadosomatic index peaked in July for both males and females. Reproductive males were still present in September for three sites, but all females from all sites had become latent by September, indicating that the spawning...