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The octopus fishery in Mexico is supported by two species, Octopus maya and an Octopus vulgaris-like species that teuthologists have named O. vulgaris type I. The main fishery species off the Yucatan Peninsula is O. maya, whereas the O. vulgaris-like species historically has supported the octopus fishery off the Mexican east coast. Management policies protect this species in the Veracruz Reef System (VRS) in the Gulf of Mexico, where artisanal fisherman catches it; however, specimens of O. vulgaris type I harvested in this reef system share haplotypes with Octopus insularis, and they cluster together in a strongly supported monophyletic clade. The species O. insularis does not belong to the O. vulgaris complex, as it was previously believed; it is related to the American octopuses, O. maya and Octopus mimus. The results indicate that O. insularis is distributed from the Gulf of Mexico to the coastal waters off southern Brazil and imply that the octopus fishery in the VRS is based on a misidentified species.

The octopuses Octopus hubbsorum and Octopus mimus are two species of octopuses that inhabit shallow waters of the eastern Pacific Ocean. The former species is found in the north, from the Gulf of California to Oaxaca, Mexico, whereas O. mimus lives in the south, from Peru to Chile. To infer the phylogenetic relationships between these species we used the mitochondrial genes cytochrome oxidase subunits I and III, and r16S with the aim of comparing their genetic distances with those of other Octopus sp. The genetic distance values between both species estimated per gene or concatenated were low (0%–1.6%) in comparison with other interspecific distances values (4.6%–18.4%). Application of 10× rule showed there is no overlap between intra- and interspecific octopus distances, whereas the application of the 4× rule confirmed that both octopuses belong to the same lineage. The resolved topologies with maximum parsimony and Bayesian approaches clustered the specimens of O. hubbsorum and O. mimus in a single clade with high bootstrap and posterior probability values (100 and 1.0, respectively). These results allow us to suggest that O. hubbsorum and O. mimus could represent the same species.

Two hundred sixty-one octopuses were obtained from August 2006 to June 2007 in Bahia de Los Angeles, BC, Mexico. Sizes ranged from 58–190 mm in mantle length. Diet was determined from 3 sources: the digestive tract analysis (hard rests), accumulations of hard prey remaining in refuges, and live prey present during capture. Ripe females had the greatest fullness weight index (FWI) whereas spawning/spent females had the lowest. During the spring, female and male octopuses showed the greatest FWI, whereas in summer they showed the lowest, coinciding with the spawning/spent stage. A total of 76 prey items from 8 phyla were found, with Mollusca being the most important phylum and xanthid crabs the most important prey year-round. During autumn and winter, more bivalves were consumed, whereas more crabs were consumed in spring. Males fed mainly on crabs during all gonad development stages, but spent males fed mostly on molluscs. In contrast, females fed mostly on molluscs, except ripe females, which inc...

This study evaluated the effect of different diets on the feeding, growth, and proximal composition of Octopus mimus. Animals were kept under controlled conditions in the laboratory for 3 mo and fed ad libitum with monodiets of the molluscs Eurhomalea lenticularis and Tagelus dombeii, and the crustacean Mursia gaudichaudi. The specific feeding rates (SFRs) of O. mimus were significantly greater in individuals fed with M. gaudichaudi (1.70% body weight per day), whereas the greatest specific growth rates (SGRs) were obtained in individuals fed with T. dombeii (0.26% body weight per day) and E. lenticularis (0.15% body weight per day). The weight increase of O. mimus was affected by the treatments, and the greatest increase throughout the duration of the experiment was observed in octopuses fed with E. lenticularis (0.12% per individual). Although the gender of the animals did not directly influence SFR and SGR, males had a greater weight increase, probably because some females laid eggs during the...

Octopus tankahkeei is a new species of cephalopod found recently in the Southern China Sea. It belongs to the class Cephalopoda, Octopoda, Octopodidae and Genus Octopus. Its discovery has attracted much attention from the fisheries industry because it has quickly become a gastronomic favorite of consumers. Because of its popularity, the aquaculture of this species would be of great economical value. The description of the sperm ultrastructure will provide information regarding the fertilization mechanism of this organism and yield an understanding of the optimal method to culture this species. In this report, the ultrastructure of the spermatozoon of Octopus tankahkeei was investigated using electron microscopy. The mature spermatozoon consists of three parts: head, neck and tail. The head contains an acrosome and the nucleus. The spiral and cone-shaped acrosome has many equidistant striations on its surface. The thin cylinder-shaped nucleus has a deep concavity at the post fossa. The neck contai...