Growth and Reproduction of the Lanternfish Stenobrachius leucopsarus

Abstract

Growth and reproductive patterns of the common lanternfish Stenobrachius leucopsarus (Eigenmann and Eigenmann) are described by length-frequency analysis, otolith analysis, and examination of ovaries. Length-frequency analysis showed that growth is approximately linear, 1.59 mm standard length per month, during the 2nd, 3rd, and part of the 4th year of life. Yearling fish average 23 mm long, 2-year-olds 41 mm, and 3-year-olds 59 mm.Otolith analyses indicate that some fish may live to be 8 years old, but confidence in this method is limited to fish 5 years old or younger. Fitting mean lengths of age-groups defined by otolith analyses with the von Bertalanffy equation gave L∞ = 85 mm, k = 0.34. Back calculation of lengths at the times of formation of otolith annuli gave another set of estimated mean lengths of age-groups, which, fitted by the von Bertalanffy equation, describes a growth curve similar to the one described by otolith analyses. The inflection in growth in weight occurs at about 4 years of age.Time of spawning, determined from egg measurements, occurs from December to March. Reproductively mature individuals are 4 years old and older. Recruitment of young size groups is also seasonal, 20- to 25-mm individuals appearing in largest proportions in trawl samples in the winter, presumably about 8 months after spawning.Comparison with other studies indicates that spawning may occur earlier in Monterey Bay, California, than off Oregon, but growth rates and sizes of age-groups I–V are similar. Comparisons with published results of otolith analyses show similar age determinations for the smaller size groups.