Life-History of the Flagfin shiner, \u3ci\u3ePteronotropis signipinnis\u3c/i\u3e, from a Blackwater Stream in Southeastern Mississippi

Flagfin shiners, Pteronotropis signipinnis, were collected from Sweetwater Creek, a second‐order blackwater stream in southeastern Mississippi, during each month of 1996. Analysis of length frequency histograms indicated a life span of 1 to 2 years. Sex ratio was not different from a 1:1 ratio. Adult males were larger and more heavily pigmented near the abdomen than females. Females were reproductive from April to mid‐August. All females attained sexual maturity by 27 mm SL and produced multiple clutches of ova. Clutch size varied from 12 to 101 ova and was correlated with SL. Mean mature oocyte diameter was 0.88 mm (range 0.76–0.96). Despite the relationship between clutch size and body size, P. signipinnis may be selected to invest in early reproduction rather than growth. This idea is supported by the small size at maturity in this species and is consistent with an opportunistic life‐history strategy