Spawning by jumbo squid Dosidicus gigas in San Pedro Mártir Basin, Gulf of California, Mexico

Abstract

Paralarvae of ommastrephid squid in the eastern Pacific Ocean are exceedingly difficult to identify at the species level due to extreme morphological similarities, fragmentary knowledge of early life history and ontogeny, and the co-occurrence of adults of 2 or more species in most areas. We employed molecular genetic methods to identify ommastrephid paralarvae and juveniles captured in the area of the San Pedro Martir basin in the central Gulf of California. Sequence analysis of a mitochondrial gene, cytochrome c oxidase I, identified all specimens analyzed (3 paralarvae and 11 small juveniles) as Dosidicus gigas and definitively ruled out other candidate species, specifically Sthenoteuthis oualaniensis. Paralarvae of the complete developmental size range were taken (1 to 10 mm mantle length), the smallest being the size expected for D. gigas at hatching. In addition, pairs of coupled adult D. gigas engaged in putative mating behavior were observed. Taken together, these findings indicate that mating, spawning and early development of D. gigas occur in this area.