Statolith microstructure, age, and maturity of jumbo squid (Dosidicus gigas) in equatorial waters of the eastern tropical Pacific Ocean

摘要

Statolith microstructure of the jumbo squid, Dosidicus gigas (d'Orbigny, 1835 in 1834-1847), was analyzed to study age, growth, and maturation based on samples collected during Chinese scientific surveys in equatorial waters of the eastern tropical Pacific Ocean from April to June 2013. We found three distinct growth zones with increments of varying width (postnuclear, dark, and peripheral zones), various checks, and aberrant microstructures. Estimated age ranged from 140 to 280 d, suggesting squid longevity is < 1 yr. Back-calculated hatching dates were from August 2012 to January 2013. Mantle length-age data were best described with a linear model, although Schnute (rho not equal 0, eta = 0) and power models also explained the growth of D. gigas. Absolute daily growth rate ranged from 1.22 to 1.40 mm d(-1) for females, and from 1.30 to 1.62 mm d(-1) for males. Size and age-at-maturity was 402 mm ML and 276 d for females, while for males, it was 314 mm ML and 202 d.