BULLETIN OF MARINE SCIENCE, 84(1): 109–121, 2009 109 Bulletin of Marine Science © 2009 Rosenstiel School of Marine and Atmospheric Science of the University of Miami REPRODUCTIVE BIOLOGY OF OCTOPUS HUBBSORUM (MOLLUSCA: CEPHALOPODA) ALONG THE CENTRAL MEXICAN PACIFIC COAST Ernesto López-Uriarte and Eduardo Ríos-Jara ABSTRACT he reproductive biology of Octopus hubbsorum Berry, 1953, was studied along the central Mexican Paciic from 1998 to 2000. In the majority of the months (15), the sex ratio was 1:1. he ratio of males to females decreased consistently with re- spect to size, weight, and sexual maturity, probably related to vertical migrations of females from deeper to shallow areas, the search of better feeding areas before reproduction, and nesting behavior of females. he dorsal mantle length and the total body weight of individuals at irst maturity were 115 mm and 758 g for females, and 70 mm and 320 g for males. hree maturity stages were recognized for females (maturing, mature, and spawning and/or already spawned) and three for males (im- mature, maturing, and mature). he females have low potential fecundity (mean ± SD = 172.05 ± 85.15 oocytes/female) and small oocytes (mean = 1.79 ± 0.14 mm), compared to other species of Octopus. he mean (±SD) potential fecundity of males was 65.92 ± 34.34 spermatophores/male. As in other Octopus spp., O. hubbsorum spawns throughout the year. However, potential fecundity of males and the number of mature and spawning females increased signiicantly during the cool-dry season. he presence of a constant mature population may be related to generally warm conditions during most of the year. Octopus hubbsorum Berry, 1953, is the most common octopus in the Mexican Pa- ciic; it is found from the central part of the Gulf of California (28°55΄N, 113°32΄W) to the southern littoral of Oaxaca (16°10΄N, 95°14΄W) (López-Uriarte et al., 2005). he species has been captured in an artisan ishery during the past 20 yrs and represents practically the total catch of octopuses for this region, which is around 1000 t yr −1 (SAGARPA, 2004). In the central Mexican Paciic, it is one of the ive most important ishery resources (Ríos-Jara et al., 2004). Data on O. hubbsorum are scarce; there are only reports on its range distribution (Aguilar and Godínez, 1997; López-Uriarte et al., 2005), a description of visible le- a description of visible le- sions in the arms and mantle associated with capture-escape trauma during ishing activities (Pascual et al., 2006), and a recent survey on its diet and feeding habits (López-Uriarte et al., unpubl. data). No information on the reproductive biology of this species has been published, despite the importance of such data to ishery man- agement. he present study provides, for the irst time, detailed information of the sex ratio, size and weight at irst maturity, fecundity, and spawning period of this species. he octopuses were obtained during a period of 2.5 yrs (May, 1998–October, 2000) from the commercial artisan catches of local ishermen at diferent localities along the central Mexican Paciic coast. Materials and Methods Study Area.—he littoral zone of Jalisco, located in the central Mexican Paciic (20°40΄ and 18°58΄N), has an approximate length of 341.9 km and many diferent coastal environments such as long rocky and sandy beaches, reef structures, estuaries, coastal lagoons, mangrove FastTrack publication