Changes of proximate composition, energy storage and condition of European hake (Merluccius merluccius, L. 1758) through the spawning season

European hake is one of the most important economic resources for South European fleets; however, not many studies on its reproductive biology have been carried out. Gonadosomatic and hepatosomatic indices and condition factor were estimated. Proximate composition was analyzed in gonad, liver and muscle as indicators of female condition status; these results were converted to energy values. Variations of these parameters during the spawning season and through the year were studied. The hake population in Galician waters has a protracted spawning season with peak spawning from February to March. The proximate composition of tissues changes considerably throughout the spawning season although population spawning asynchrony masks temporal patterns. This work corroborates that energy dynamics associated with egg production in European hake are different from those observed in species from temperate waters (5°–10 °C), depending more on environmental conditions and food availability during the spawning season than on body energy reserves.