Reproduction of Merluccius merluccius (Actinopterygii: Merlucciidae) from the northern Atlantic coasts of Morocco based on histological analysis of gonads

The hake (Merluccius merluccius) fishery occupies an important place in the Moroccan trawl fishery. Despite the ecological and commercial value of this species, the reproductive biology of European hake populations in Moroccan coastal waters has been little studied. Here, we describe the seasonal variations of gonad histology of hake collected from August 2017 to August 2018 along the northern Atlantic coast of Morocco. The histological changes were compared with macroscopical changes, and the body length at first maturity (L50) was calculated. The results revealed differences between macroscopic and histological maturity staging of the gonads. The L50 was estimated to be 34.7 cm for females and 28.6 cm for males (histology-based) and 30.6 cm for females and 26.8 cm for males (macroscopy-based). In addition, the observations of ovarian maturity indicated the presence of a protracted spawning season throughout the year with a peak around January and in midsummer.