Feeding strategy and cannibalism of the Argentine hake Merluccius hubbsi

Abstract

The diet composition and feeding strategy of the Argentine hake Merluccius hubbsi in the San Matías Gulf were analysed in order to use this information for the sustainable management of the fishery. Merluccius hubbsi behaved as an opportunistic predator. Small M. hubbsi consumed planktonic crustaceans, whereas medium and large fish ate numerous prey taxa with low frequency of occurrence and variable specific abundance. Intra- and intercohort cannibalism were detected in all size groups and were particularly significant in large M. hubbsi. Medium-sized M. hubbsi consumed small conspecifics and large-sized M. hubbsi consumed both small and medium M. hubbsi. These results indicate that the removal of large M. hubbsi by fishing may increase the risk of overfishing by two combined effects: a direct effect of recruitment-overfishing and an indirect effect of growth-overfishing through an enhanced cannibalism of medium M. hubbsi on small M. hubbsi. Intra- and intercohort cannibalism and other trophic relationships in the M. hubbsi should therefore be considered explicitly in stock assessment models.

Stable isotope evidence supports pelagic fishing by hunter-gatherers in southern South America during the Late Holocene

“…and the other two pelagic predator species (Macruronus magellanicus and Thyrsites atun) is also noteworthy. This observation fits well with modern observations in that M. magellanicus is a staple in the diet of Merluccius sp., as well as the cannibalistic habits identified in the latter species (Ocampo Reinaldo et al, 2011).…”

“…Modern δ 15 N values of muscle have shown that the Argentine hake (Merluccius hubbsi) and Southern hake (Merluccius australis) have a higher trophic level position than the Patagonian grenadier (Ciancio et al, 2008), as the former species characterized as consumers of intermediate size fish and squid and the latter as a macrozooplankton feeder. Cannibalism identified in the Argentina hake (Ocampo Reinaldo et al, 2011) could also explain the difference in trophic levels. No significant difference in δ 13 C values of muscle was observed between those species (Ciancio et al, 2008).…”

Spatio‐temporal variability in the cannibalistic behaviour of European hake Merluccius merluccius: the influence of recruit abundance and prey availability

“…(). This is contrary to the results of other authors, who reported that the highest levels of cannibalism were found in larger individuals (Roel & MacPherson, ; Carpentieri et al ., ; Mahe et al ., ; Ocampo Reinaldo et al ., ; Link et al ., ). The recruits and spawners depth pattern found in the study area implies a spatial segregation and could be the main reason for the virtual absence of cannibalism in large specimens.…”

Adaptation of diet in a changed environment: Increased consumption of lobster krill Munida gregaria (Fabricius, 1793) by Argentine hake

“…Owing to Argentine hake's commercial importance in the South Atlantic Ocean, its high abundance and the fact that it is an important predator in the Patagonian shelf waters (Laptikhovsky & Fetisov, ), many studies have examined its diet composition (Angelescu & Cousseau, ; Angelescu, Gneri, & Nani, ; Angelescu & Prenski, ; Belleggia, Figueroa, Irusta, & Bremec, ; Cordo, ; Ocampo Reinaldo, González, & Romero, ; Ruiz & Fondacaro, ; Sánchez, ; Sánchez & García De La Rosa, ; Sánchez & Prenski, ; Temperoni, Viñas, & Buratti, ). Although the feeding habits of Argentine hake have been studied in detail, there is no work analysing long‐term variations in diet composition.…”