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El calamar gigante Dosidicus gigas (D'Orbigny 1835) es una especie endémica del Océano Pacífico oriental que se distribuye aproximadamente entre 40ºN y 45ºS (Nigmatullin et al. 2001). Constituye un importante recurso pesquero en el Golfo de California (Ehrhardt et al. 1983, Morales-Bojórquez et al. 2001), en la región del domo de Costa Rica (Ichii et al. 2002) y frente a las costas de Perú y Chile (Taipe et al. 2001). Dosidicus gigas es un componente importante dentro del ecosistema del Golfo de California ya que sus juveniles pueden constituir una de las principales presas de tiburones (Aguilar-Castro y Galván-Magaña 2003) y grandes peces pelágicos

This study examines the abundance and distribution of Panama brief squid (Lolliguncula panamensis) caught during 15 fishery surveys in the Gulf of California in 2003–2006 and 2008. A total of 2460 individuals were captured in 66 positive squid trawls. Based on the seasonal sea surface temperature pattern, captured individuals were grouped into two periods: cold (<22 ºC: December, January, February, March, and April 2003–2006 and 2008) and warm (≥22 ºC: May, June, July, August, September, October, and November 2003–2006 and 2008). During the cold period, 1579 organisms were sampled, and during the warm period, 881. Abundance by sex showed that females were more abundant during both periods (62% cold, 57% warm) than males (17% cold, 12% warm). During both periods, females (99.6% cold, 91.0% warm) as well as males (99.3% cold, 95.3% warm) presented reproductive activity (maturing and mature stages), and they were captured at depths between 7 and 40 m. The highest abundances occurred in diurnal trawls at an average depth of 40 m during the cold period and 24 m during the warm period.

The jumbo squid Dosidicus gigas is an ecologically and commercially important species whose northernmost geographic limit is the Gulf of California. However, over the last decades this species has extended its geographic distribution polewards, with associated impacts on the ecosystem. The origin of range-shifting individuals is poorly understood; therefore, we aimed to identify and characterize the northernmost spawning habitat of this species. Implications of the location and oceanographic conditions of the spawning habitats, migration capacity and life history characteristics of D. gigas are also discussed to elucidate its migration pattern. The northernmost spawning area was located between the biological activity centres (BACs) around the Gulf of Ulloa at the west coast of southern Baja California Peninsula during winter, summer and autumn 2005. Generalized linear models indicated that the interaction of sea surface salinity and thermocline depth, and the effect of latitude and sea surface temperature explained most of the variability in paralarval presence, whereas chlorophyll a and latitude explained paralarval abundance. Simulations indicated that paralarvae were dispersed towards the southwest or temporarily remained between BACs. The northwards incursion of D. gigas may be favoured by BACs and upwelling events along the coast of the northeastern Pacific. In warm years, D. gigas is likely to spawn off the Baja California Peninsula, it may actively migrate as far north as Alaska (USA) tracking BACs and upwelling conditions in search of feeding grounds, and it may return from different areas along the northeastern Pacific to spawn off the Baja California Peninsula.

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