Loligo opalescens

The market squid Loligo opalescens Berry, 1911 (Myopsida, Loliginidae) is a small squid that attains a maximum reported mantle length (ML) of 230 mm (O’Dor, 1982). It is distributed along the west coast of North America from the middle of Baja California northvvard to southeastern Alaska (Okutani,/pers. comm., 1982). This species has been fished commercially since at least 1863 in the vicinity of Monterey, California, and today it is widely believed to be an under-utilized fisheries resource in the northeastern Pacific. Partially because of this potential, many studies relating to L. opalescens have been concerned with its fishery biology. The important observations of Fields (1965) on the anatomy, embryonic development, life history and fishery of the market squid still serve as the starting point for all subsequent studies of this species. Because Fields' work was based almost exclusively upon the spawning population commercially fished at Monterey, more recent studies have considered other fishing areas and techniques (Kato & Flardwick, 1975) and investigated other aspects of life history including spermatogenesis, oögenesis, age and growth, predator-prey relationships and racial or stock discrimination (Recksiek & Frey, 1978). Additional studies of note are those on mating behaviour in the field and in the laboratory (Hurley, 1977) and school structure and schooling behaviour (Hurley, 1978). Information on early life history ofhatchling and juvenile L. opalescens has been obtained from field studies (Okutani & McGowan 1969) and through laboratory-rearing studies (Hurley, 1976; Hanlon et al.,1979; Yang et al., 1980). In addition, many important physiological studies of the cephalopod nervous System, cephalopod chromatophores and iridescent cells, and cephalopod metabolism have used L. opalescens as an experimental model. While these studies are not directly concerned with the life cycle of this species, they Supplement and complement this life history review