Li Jiang Tao, Lin Xiao Tao, Zhou Chen Hui, Zeng Peng, Xu Zhong Neng, Sun Jun
Institute of Hydrobiology, Jinan University/Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institutes, Guangzhou 510632, China.
Ying Yong Sheng Tai Xue Bao. 2016 May;27(5):1639-1646. doi: 10.13287/j.1001-9332.201605.028.
To explore the sexual dimorphism of Tanichthys albonubes and its relationship with swimming performances, the morphological characteristics of fins and trunks of male and female T. albonubes were measured and analyzed by using multivariate statistical analysis methods, aiming to explore the difference and its mechanism of swimming performance between male and female under different selected pressure in long-term evolution period and then, providing meaningful information for the protection of T. albonubes. The results showed that body lengths, head depths and breadths, caudal fin areas, distances of snout tip to occipital bone terminus and ventral fin origin to dorsal fin terminus had no significant difference between male and female T. albonubes. The females had significantly higher values in head depths, body breadths, distances of ventral fin origin to dorsal fin origin, snout tip to dorsal fin and to anal fin origin, occipital bone terminus to dorsal fin origin than those in the males. However, head lengths, pectoral fin, dorsal fin, ventral fin and anal fin areas were significantly lower in the females. The results of principal component analysis showed that the contribution rate of the first principal component (PC1) was 74.2%. Obviously loading factors were body lengths, depths and breadths, head lengths, breadths and depths and the distances of each fin mainly reflecting body overall characteristic parameters of T. albonubes. For the second principal component (PC2), the contribution rate was 15.7% and the obviously loading factors were pectoral fin, dorsal fin, ventral fin and anal fin areas which mainly reflected the characteristic parameters of fins. The gender identification of T. albonubes was indistinguishable on PC1, but could be obviously distinguished from PC2. Accuracy rates of sexual discriminant equation which was established by pectoral fin, dorsal fin, ventral fin and anal fin areas and body breadths were 91.8%-92.5%. The results of swimming performance showed that burst swimming speeds (U) had no significant difference between male and female T. albonubes. However, the critical swimming speeds (U) were significantly decreased in the females than in the males. The findings indicated that the sexual dimorphism of T. albonubes was mainly concentrated on fin characteristics associating with swimming performance. Also having lower U due to its lower pectoral fins areas than the male, the female T. albonubes had longer hindquarters cadres to ensure high U which facilitated them to avoid predators and other emergency events in volatile streams. Larger fin areas than in the female caused higher U in the male contributing to chasing female in breeding period and other persistent exercises.
为探究唐鱼的两性异形及其与游泳能力的关系，运用多元统计分析方法对唐鱼雌雄个体的鳍和躯干形态特征进行测量与分析，旨在探讨长期进化过程中不同选择压力下雌雄唐鱼游泳能力的差异及其机制，进而为唐鱼的保护提供有意义的信息。结果表明，唐鱼雌雄个体的体长、头深和头宽、尾鳍面积、吻端至枕骨末端的距离以及腹鳍起点至背鳍末端的距离无显著差异。雌性唐鱼在头深、体宽、腹鳍起点至背鳍起点的距离、吻端至背鳍和至臀鳍起点的距离、枕骨末端至背鳍起点的距离方面的值显著高于雄性。然而，雌性唐鱼的头长、胸鳍、背鳍、腹鳍和臀鳍面积显著低于雄性。主成分分析结果显示，第一主成分（PC1）的贡献率为74.2%。显著载荷因子为体长、体深和体宽、头长、头宽和头深以及各鳍的距离，主要反映唐鱼的身体整体特征参数。对于第二主成分（PC2），贡献率为15.7%，显著载荷因子为胸鳍、背鳍、腹鳍和臀鳍面积，主要反映鳍的特征参数。唐鱼在PC1上的性别鉴定无法区分，但在PC2上可明显区分。由胸鳍、背鳍、腹鳍和臀鳍面积以及体宽建立的性别判别方程的准确率为91.8% - 92.5%。游泳能力测试结果表明，唐鱼雌雄个体的爆发游泳速度（U）无显著差异。然而，雌性唐鱼的临界游泳速度（U）显著低于雄性。研究结果表明，唐鱼的两性异形主要集中在与游泳能力相关的鳍的特征上。由于雌性唐鱼的胸鳍面积比雄性小，其U较低，因此雌性唐鱼具有更长的后躯干部，以确保较高的U，便于它们在多变的溪流中躲避捕食者和其他紧急情况。雄性唐鱼鳍面积比雌性大，导致其U较高，有助于在繁殖期追逐雌性和进行其他持续运动。
