NATURAL HYBRIDIZATION BETWEEN BLACK-AND-WHITE CRAPPIES (POMOXIS) IN 10 ALABAMA RESERVOIRS

Natural hybridization between black crappie (Pomoxis nigromaculatus) a nd white crappie (P. annularis) has been documented in a few southeast ern reservoirs. We examined the extent of hybridization in 10 Alabama reservoirs from 1992 through 1995. Using starch-gel electrophoresis, w e found that natural hybridization between black and white crappies ra nged from 0-21%. Hybridization was rare or absent in reservoirs outsid e of the Coosa River basin (range 0-2%), while hybrid crappies compris ed 14% and 21% of the crappie populations in Lay and Weiss reservoirs from the Coosa River. Even though higher percentages of natural hybrid ization were detected in two of the Coosa River impoundments, second-g eneration and higher (F-x) hybrids were uncommon. First-generation (F- 1) hybrid crappies were ca. six times more abundant than F-x individua ls from Weiss and Lay reservoirs, indicating that offspring of F(?)1 h ybrids are not recruiting to these populations.