Abstract
The estimated minimum standard length (SL) to attain sexual maturity in largemouth bass, Micropterus salmoides, in Japan, is 230 mm. We observed the gonadal development of smaller largemouth bass (two males, 162-169 mm SL; two females, 182-204 mm SL) captured in an artificial pond located at the University of Shiga Prefecture. This study and two previous reports suggest that largemouth bass can mature at smaller sizes than previously reported. Maturity with smaller body size may be related to genetic exchange with other smaller geographic subspecies and environmental factors, such as the amount of food and water temperature.
