南半球夏季西南大西洋阿根廷外海巴西真鲳群体组成特征初步研究

Preliminary study on population composition characteristics of Southwest Atlantic butterfish (Stromateus brasiliensis) off the waters of Argentina in the Southwestern Atlantic Ocean during the Austral Summer

摘要:

根据2009年12月-2010年1月在西南大西洋阿根廷外海测定的168尾巴西真鲳（Stromateus brasiliensis）生物学数据，对南半球夏季巴西真鲳的群体组成特征，尤其是全长（L_T）和叉长（L_F）组成、全长和体重（W_B）关系、性比、性腺成熟度及性腺指数等基本生物学特性进行了分析。结果表明：（1）巴西真鲳全长范围为23.6～34.2 cm，优势全长组为24.0～28.0 cm；叉长范围为21.6～30.3 cm，优势叉长为22.0～26.0 cm；全长与叉长关系为L_T=1.1411L_F-6.7702（R²=0.962 6）。（2）巴西真鲳全长与体重关系为W_B=3×10^-5L_T^2.8789（R²=0.924 4)。（3）巴西真鲳平均雌雄性比为1∶0.3。（4）12月至1月，西南大西洋巴西真鲳性成熟度均〖WTBZ〗为Ⅱ或Ⅲ级；各全长组巴西真鲳性成熟度存在显著性差异（χ²=104.86，P<0.05）。（5）性腺指数随着体长的增大而呈升高的趋势，性腺指数的范围为1.05～8.33。

Abstract:

Based on the biological data (n=168) collected in the southern Atlantic Ocean off Argentina during December 2009 to January 2010, the present study analyzed the biological characteristics of Southwest Atlantic butterfish (Stromateus brasiliensis) in the Austral Summer, including total length (L_T), fork length (L_F), the relationship between L_T and W_B, sex ratio, sexual maturity and gonadsomatic index. The results showed that: (1) The L_T ranged from 23.6 to 34.2 cm with dominating L_T of 24.0 to 28.0 cm, the L_F ranged from 21.6 to 30.3 cm with dominating L_S of 22.0 to 26.0 cm. The relationship between L_T and L_S was L_T=1.141 1L_F-6.770 2 (R²=0.962 6). (2) The relationship between L_T and W_B was W_B=3×10^-5 L_T^{2.878 9} (R²=0.924 4). (3) The ratio of female to male for Southwest Atlantic butterfish was 1∶0.3. (4) The sexual maturity of Southwest Atlantic butterfish were Stage Ⅱ or Ⅲ during December to January. Significant difference can be found for the sexual maturity of Southwest Atlantic butterfish among L_T classes (χ²=104.86, P<0.05). (5) The gonadsomatic index was increased with the increasing of fork length and the gonadsomatic index ranged from 1.05 to 8.33.