秘鲁外海茎柔鱼角质颚的形态特征及其与个体大小和日龄的关系

角质颚是头足类重要的硬组织,被用于估算其个体大小及其生物量等。根据2009~2014年中国鱿钓船在秘鲁外海(79°22'W~84°30'W、10°00'S~18°16'S)采集的茎柔鱼(Dosidicus gigas)样本,提取出1 346ind茎柔鱼的角质颚,并对角质颚的形态进行了分析,建立了角质颚的形态特征参数与胴长、体重和日龄之间的关系。结果显示,雌性个体角质颚各形态参数的平均值均大于雄性个体,在角质颚12个形态参数中,上喙长(UHL)、上脊突长(UCL)、上侧壁长(ULWL)、下脊突长(LCL)、下侧壁长(LLWL)、下翼长(LWL)与胴长、体重、日龄之间的相关系数较高。胴长与角质颚各形态参数的关系在雌、雄个体间的差异性均显著(P0.05),体重、年龄与角质颚各形态参数的关系在雌、雄个体间的差异性均不显著(P0.05)。角质颚各形态参数与胴长、日龄之间呈线性关系;除上侧壁长外,角质颚的其它形态参数与体重之间呈幂指数关系。主成分分析认为,第一主成分解释上、下角质颚形态的贡献率分别为95.69%和95.11%,在上角质颚和下角质颚的形态参数中,载荷系数最大的形态参数分别为上脊突长和下侧壁长。研究认为,上述关系式的建立可以用于茎柔鱼的个体大小、生物量和日龄的估算。

Beak morphological characteristics of Dosidicus gigas off the Peruvian Exclusive Economic Zone(EEZ) and their relationship with body size and daily age

Beak is an important hard structure of cephalopod used for estimating the individual size and biomass.In this study, samples of jumbo flying squid(Dosidicus gigas) were collected by the Chinese squid jigger fleet during 2009-2014 off the Peruvian Exclusive Economic Zone (79°22′W-84°30′W,10°00′S-18°16′S).The beaks were sampled from 1 346 ind and the morphologies of these beaks were analyzed.Moreover, the relationships between the morphological parameters and mantle length, body weight and daily age were built.The results showed that the average values of the beak morphological parameters of females were greater than those of males.Among the 12 beak morphological parameters,the upper crest length, the upper rostral length, the upper lateral wall length, the lower crest length, the lower lateral wall length, the lower wing length were highly correlated with the mantle length, the body weight and the daily age.The relationships between the beak morphological parameters and the mantle length were best described by linear models, and their were significant differences between females and males (P<0.05).The linear functions were optimal to describe the relationships between the beak morphological parameters and daily age, and there was no significant difference between females and males (P>0.05).Except for the upper lateral wall length, the other beak morphological parameters were best fitted with the body weight by power models and no significant difference was found between females and males(P<0.05).The principle component analysis indicated that the contribution rate of the first principle component of upper and lower beak morphological parameters were 95.69% and 95.11%, respectively.The beak morphological parameters with the maximum load coefficient were upper crest length (UCL) and lower lateral wall length (LLWL).The relation formula established above can be used for estimating the size, biomass and daily age of Dosidicus gigas in this region.