盐度对中国东南沿海两种常见藤壶幼虫发育的影响

网纹藤壶Amphibalanus reticulatus和鳞笠藤壶Tetraclita squamosa squamosa是我国东南沿海两种常见的海洋污损生物种类, 在海洋生态系统中占有重要地位。探讨这两种藤壶的幼虫发育与盐度的关系有助于丰富和发展海洋生物学知识, 并为海洋污损生物防除相关工作的开展提供数据资料。研究探讨了网纹藤壶和鳞笠藤壶无节幼虫在盐度为6‰、12‰、18‰、24‰、30‰(对照组)和36‰的培养条件下的发育状况, 观察记录5天后幼虫的存活率和各期幼虫所占百分比, 采用最小显著差数法进行差异显著性分析。结果表明, 当水体盐度≤18‰时, 会严重阻滞网纹藤壶和鳞笠藤壶幼虫的发育, 甚至导致死亡; 而当盐度≥24‰时, 这2种藤壶幼虫的成活率虽不会随盐度改变发生显著变化, 但盐度为30‰的水体更有利于网纹藤壶幼虫的发育, 而鳞笠藤壶幼虫发育状况受盐度变化的影响不大, 具备更强的耐受能力。

Effects of salinity on larval development of two common barnacles from the southeast coast of China

The acorn barnacles Amphibalanus reticulatus and Tetraclita squamosa squamosa are common fouling species off the southeast coast of China, which play an important role in marine ecosystems. Understanding the effects of salinity on larval development of the two common barnacles will increase our knowledge on marine biology and may also provide data useful in the field of marine fouling control. In this study, the nauplius larvae of the barnacles A. reticulatus and T. squamosa squamosa were reared in seawater with salinities of 6‰, 12‰, 18‰, 24‰, 30‰ (Control), and 36‰, respectively. After being cultured for five days, the surviving individuals were counted, and their developmental stages were analyzed. The mean values of larval survival rate and the percentage of larvae at various developmental stages in the control and treatment groups were compared with the Least Significant Difference (LSD) test. The results showed significant negative impacts on larval development and survival of both species when the salinity was equal or less than or equal to 18‰. In the salinities of 6‰, 12‰ and 18‰, larval development was inhibited significantly, even to the point where all larvae died. If the salinity rose to 24‰ or higher, there was no significant difference in the larval survival rates of both barnacle species between the control and treatment groups. The salinity at 30‰ was the optimum for larval development of A. reticulatus. Moreover, the larvae of T. squamosa squamosa had greater tolerance to salinity stress with no significant differences occurred during its larval development among the groups in the salinities of 24‰, 30‰ and 36‰.