个体差异对西南大西洋阿根廷滑柔鱼角质颚外部形态变化的影响

角质颚是头足类重要的硬组织,广泛用于头足类分类及资源量估算等研究中。根据2010年中国鱿钓船在西南大西洋海域采集的2 916对阿根廷滑柔鱼角质颚样本,对角质颚12项外部形态参数进行测量,根据主成分分析结果,以角质颚的上头盖长(UHL)、上脊突长(UCL)、上翼长(UWL)、下头盖长(LHL)、下脊突长(LCL)和下翼长(LWL)作为角质颚各区外部形态变化的特征指标,以头盖长和脊突长之比(HL/CL)、喙长和脊突长之比(RL/CL)、喙宽与脊突长之比(RW/CL)、侧壁长和脊突长之比(LWL/CL)、翼长和脊突长之比(WL/CL)分别作为角质颚各区外形变化的指标,利用方差分析(ANOVA)和最小显著差多重比较法(LSD)研究不同性别、性腺成熟度和胴长范围对角质颚各区生长和外形变化的影响。结果表明,不同性别间UHL、UCL、UWL、LHL、LCL和LWL的变化存在显著性差异,相同性别不同性腺成熟度、不同胴长范围内的UHL、UCL、UWL、LHL、LCL和LWL的变化均存在显著性差异,而不同性别、不同性腺成熟度和不同胴长范围间上、下颚的HL/CL、RL/CL、RW/CL、LWL/CL、WL/CL的变化不存在显著性差异,并且其值基本恒定,上、下颚分别为78.04%、22.46%、17.28%、81.41%、23.07%和50.69%、43.31%、41.13%、144.98%、93.68%。研究表明,不同个体对阿根廷滑柔鱼角质颚外部形态变化有显著的影响。

Effects of individual size on beak morphology of Illex argentinus in the Southwestern Atlantic Ocean

Beak is one of the most important hard tissues of Cephalopoda which is usually used in fishery biology and biomass estimation.According to the 2 916 samples of short-fin squid Illex argentinus collected by Chinese squid jigging vessels from January to March in 2010 in Southwest Atlantic Ocean,the morphologic parameters were measured and the growth characteristics of beak were studied.The result of principal component analysis of twelve morphologic indices showed that upper hood length(UHL),upper crest length(UCL),upper wing length(UWL),lower hood length(LHL),lower crest length(LCL)and lower wing length(LWL)could be used to represent the length growth features of beak of each dome,and the ratios of HL to CL,RL to RL,RW to WL,LWL/CL and WL/CL could be used as indicators of entire growth for beak(upper beak and lower beak)growth,and the each dome growth,the entire beak growth impacted by sex,gonad maturity and individual size were analyzed by the analysis of variance(ANOVA)and least-significant difference(LSD).The results indicated that the UHL,UCL,UWL,LHL,LCL and LWL were closely related to sex,and for females or males,the UHL,UCL,UWL,LHL,LCL and LWL were closely related to gonad maturity and mantle length,however the ratios of HL/CL,RL/CL,RW/CL,LWL/CL,WL/CL were nearly constant without changing with sex,gonad maturity or different mantle length with the ratios of 78.04%,22.46%,17.28%,81.41% and 23.07% for upper beak and 50.69%,43.31%,1.13%,144.98% and 93.68% for lower beak respectively.This study suggested that there are significant effects of individual size on beak morphology of I.argentinus in the Southwestern Atlantic Ocean.