Sexual dimorphism in the fish Dormitator maculatus (Teleosti: Eleotridae) from Alvarado Lagoon, Veracruz, Mexico

The shape of the urogenital papilla is used to visually determine the sexual dimorphism of Dormitator maculatus . However, it is occasionally not possible to determine this in practice. The objective of the present study was to propose and statistically validate other morphometric measures to fulfill this same purpose. The analysis was designed on the basis of a group of previously identified adults with urogenital papilla. It was found that the most useful morphometric measures are related to the size and weight of the species. The dorsal fins and the geometric structure of the head were also recommended as morphometric measures. The males are larger in size, they are robust with the fin 1DFL longer compared to the 2DFL fin and have a broad, elongated head. Females are smaller in size, slightly robust, with longer 2DFL fins compared to 1DFL fins, and have slender, not elongated heads. In the Alvarado lagoon, sexual differentiation in D. maculatus is important due to the selective exploitation of its gonads (mainly on females). For this reason, and to avoid errors in the identification of females for protection purposes, the results obtained are a viable alternative.