“…Available methods for sex identification in fishes include histological examination of the gonads (Baroiller et al , ), morphological differences between males and females (Vøllestad & L'Abée‐Lund, ; Merz et al , ), endoscopy and ultrasound‐based techniques (Martin‐Robichaud & Rommens, ; Wildhaber et al , ), palpation (Kano, ), biopsy (Whalley & Lowery, ), biochemical and immunological techniques, (Le Bail & Breton, ; Craik & Harvey, ; Heppell & Sullivan, ) and molecular genetic techniques (Griffiths et al , ). Some of these methods require sacrificing individuals, which precludes further study, or are expensive, time‐consuming, uncertain, species specific or require substantial experience.…”