Skipped spawning in the Patagonian stock of argentine hake, Merluccius hubbsi

MACCHI, G.J.; DIAZ, M. V.; LEONARDUZZI, E.; MILITELLI, M. I.; RODRIGUES, K.

FISHERY BULLETIN

NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE

Lugar: US; Año: 2016 vol. 114 p. 397 - 408

0090-0656

We analyzed macroscopic and histological maturity data of Argentine hake (Merluccius hubbsi) collected off Argentina in the spawning area of the Patagonian stock of this species between 2005 and 2014 to determine the frequency of skipped spawning. This study revealed that the only category of this phenomenon observed for Argentine hake was the resting stage. The analysis of 58,891 adult females of Argentine hake sampled during their reproductive peak indicates that, annually, between 6% and 22% of them were skipped spawners. These females were located mostly in the periphery of the spawning area, in deeper (>90 m) and colder waters (6?7°C). Individuals that had skipped spawning had a more intense feeding activity and a better nutritional condition than did females collected in the main spawning area, evaluated by Fulton?s condition index (K=0.68?0.75). In contrast, postspawning females showed the poorest condition (K=0.62?0.68) because of the energy cost involved in reproduction. Skipped spawners were mostly young females with a modal age of 3 years and a modal size of 38 cm TL. These results indicate that a significant proportion of individuals that already had their first annual spawning could skip the next one and stay on the periphery of the reproductive area to feed.