Effects of Increased Suspended Sediment on the Reproductive Success of an Upland Crevice‐Spawning Minnow

Little is known about the effects of increased suspended sediment on the reproductive behavior and spawning success of fishes, especially North American nongame fishes. I investigated the effects of increased suspended sediment concentration (SSC; 0, 25, 50, 100, and 500 mg/L) on the spawning success of the crevice‐spawning whitetail shiner Cyprinella galactura . Spawning success was measured during two week‐long experiments in terms of spawning effort (the number of replicate tanks in which spawning occurred) and spawning output (number and developmental stages of propagules). Spawning effort decreased from seven of eight control tanks to four of eight tanks at 500 mg/L. The total mean number of propagules at 500 mg/L was 10–14% of the output in the lower SSC treatments. The fact that significantly more eggs than larvae were observed with increasing SSC suggests that spawning was delayed in tanks with higher SSC. A comparison of propagule developmental stage with sediment settling curves allowed an estimation of mean SSC when propagules were spawned. The number of propagules spawned was inversely and significantly related to mean SSC during spawning. Whitetail shiner spawning success was moderately affected by the SSCs used in this study. Comparison of these results with those of a similar study involving the tricolor shiner C. trichroistia suggests that whitetail shiners are slightly more tolerant of excessive sedimentation but show reduced spawning success at SSCs commonly observed in southern Appalachian Upland rivers.