Length or weight of the fish when it attains maturity as defined by: (1) the minimal size at which maturity is reached; (2) the size at which 50% of the fish of that size are mature.
SIZE-AT-FIRST-MATURITY
Meaning of SIZE-AT-FIRST-MATURITY in English
Fishery English glossary. Английский глоссарий рыболовства . 2012