“…Species of Callinectes are also a bycatch of small‐scale fisheries (Severino‐Rodrigues, Pita, & Graça‐Lopes, 2001). The reproductive biology, population structure, and sexual maturity of these species has been well‐studied (Costa & Negreiros‐Fransozo, 1998; Mantelatto & Fransozo, 1996, 1997, 1999; Negreiros‐Fransozo, Mantelatto, & Fransozo, 1999; Sant'Anna, Turra, & Zara, 2012; Sforza, Nalesso, & Joyeux, 2010; Watanabe, Sant'Anna, Hattori, & Zara, 2014). However, there is no ultrastructural description of the male reproductive system of blue crabs.…”