Population dynamics of the squidsDosidicus gigas(Oegopsida: Ommastrephidae) andDoryteuthis gahi(Myopsida: Loliginidae) in northern Peru
2015
Ibanez, Christian M. | Argüelles, Juan | Yamashiro, Carmen | Sepulveda, Roger D. | Pardo-Gandarillas, Cecilia | Keyl, Friedemann
Pelagic squids of continental shelf ecosystems mostly include oceanic and migratory species of the family Ommastrephidae and neritic species of the family Loliginidae. These two families have contrasting life history strategies; ommastrephids spawn in the open ocean and are thought to have a high dispersal potential, while loliginids spawn in the bottom and likely have a low dispersal potential. Consequently, these squid species should display different patterns in their population dynamics, which can be inferred through commercial catches of these organisms. To study the population dynamics of the Ommastrephidae and the Loliginidae families, monthly time series catches of Dosidicus gigas and Doryteuthis gahi were used. These artisanal fishery catches were made in northern Peru from 1999 to 2010. These catches were standardized to construct autocorrelation functions so that the relationship between catch dynamics and short-term environmental change (thermal anomalies of sea surface temperature were used as a proxy) could be studied. The results revealed that increases in catches of D. gigas and D. gahi are not related to thermal anomalies, but rather a pattern of drastic fluctuations in D. gahi catch sizes are seen. In, both species, temporal relationships indicate that the annual growth rate and changes in abundance can be modeled as a function of the catch density observed in previous years. We propose that these population differences result from the contrasting life history strategies and differential habitat use of these two squid species.
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Editeur Elsevier Science
ISSN 0165-7836Cette notice bibliographique a été fournie par Thünen-Institut
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