Age and growth of Sthenoteuthis oualaniensis based on statolith in the eastern Indian Ocean

Based on the analysis of squid growth increments, the squid growth characters were study and offered reference for the fishery production and utilize of Sthenoteuthis oualaniensis in the eastern Indian Ocean. By calculated the absolute growth rate and instantaneous growth rate of S. oualaniensis, the difference of squid growth rate was analysed, and based on the Akaikes's information criterion (AIC), fit out the optimal growth model. The result showed that the S. oualaniensis age ranged 40-99 d in the medium form, and the S. oualaniensis age ranged 40-79 d in the dwarf form in the eastern Indian Ocean. The medium form S. oualaniensis age was greater than the dwarf form, and the female S. oualaniensis age was greater than the male. The S. oualaniensis age was lower in the equatorial seas, and the squid age was higher in higher latitude area. The S. oualaniensis mantle length absolute growth rate ranged 0.39-2.16 mm/d, and the instantaneous growth rate ranged 0.35%-1.78%. The S. oualaniensis body weight absolute growth rate ranged 0.54-7.70 g/d, and the instantaneous growth rate ranged 1.20%-5.20%. The S. oualaniensis mantle length and body weight absolute growth rate increased with the increase of age. The female S. oualaniensis growth rates were higher than the male S. oualaniensis. The growth models were fitted with age and mantle length data, and the AIC values of each model were calculated. The minimum AIC value was liner model in total, power function model in the medium form male S. oualaniensis, liner model in the medium form female S. oualaniensis, power function in the dwarf form male S. oualaniensis, index model in the dwarf form female S. oualaniensis. The age and growth rate of female squid was higher than that of male, and the medium form higher than that of dwarf form in the eastern Indian Ocean.