Meeting Abstract
There are no published studies explicitly identifying the background levels of intersex in male Largemouth Bass (Micropterus salmoides), and this lack of knowledge limits our ability to interpret the species-specific severity of intersex. For example, we would interpret perturbations to fecundity to be minimal if a population exhibited a hypothetical value of 65% intersex when compared to a natural background level of 60% intersex. In contrast, the effect of intersex on fecundity is interpreted to be much greater if the hypothetical background level was 0% intersex. We hypothesized the occurrence and prevalence of intersex should be the same among the Chattahoochee River and two of its tributaries, Columbus, GA, USA. Largemouth Bass were collected using backpack and boat electrofishing techniques from Lindsey and Heiferhorn creeks, and Lake Oliver of the Chattahoochee River. Gonads from all fish were prepared histologically and stained using hematoxylin and eosin. In Largemouth Bass from Lake Oliver (n=37 males), the occurrence of intersex was 76%. However, in Lindsey and Heiferhorn creeks (n=20 males), none of the males exhibited intersex; therefore, the background level of intersex is 0%. Conversely, the occurrence of intersex in Lake Oliver is markedly higher and present in most of the males examined. This evaluation demonstrates that no intersex should be expected in Largemouth Bass and also showcases the extremes in intersex among connected waterbodies within the same drainage.
