温度对网纹纹藤壶幼虫发育和附着的生物学效应

Influence of temperature on larval development and settlement of the acorn barnacle Amphibalanus reticulatus

文章探讨了网纹纹藤壶(Amphibalanus reticulatus)幼虫处于12°C、18°C、24°C、30°C和36°C环境中的发育和附着状况。结果表明,网纹纹藤壶无节幼虫经历96h的发育后,幼虫的存活率分别为99.0%±1.2%(12°C)、95.0%±4.8%(18°C)、92.0%±2.8%(24°C)、80.0%±10.6%(30°C)和0(36°C);在12~30°C的范围内,温度升高能显著促进幼虫的发育。网纹纹藤壶金星幼虫在96h的培养过程中,其存活率在所有温度条件下始终维持在100%;在18°C至36°C的温度范围内金星幼虫均可附着,其中30°C条件下附着率最高,可达84.5%±12.1%,而在12°C则始终无金星幼虫附着。综合幼虫的存活率、发育进程和附着状况来看,网纹纹藤壶幼虫发育及附着的适宜温度为18~30°C。

Temperature is one of the most important environmental factors affecting marine life.It is of great significance for academic and industrial communities to understand its influence on the larval development and settlement of the acorn barnacle Amphibalanus reticulatus.In the present study,two experiments were carried out,one for the effect of temperature on the development of nauplii and the other for the settlement of cyprids.In ExperimentⅠ,newly-hatched nauplii were reared at 12°C,18°C,24°C,30°C,and 36°C,respectively,fed by the alga Platymonas subcordiformis with initial concentration around 8.0×104 cells·mL–1.After 96 hours,the surviving individuals were counted and their developmental stages analysed.In ExperimentⅡ,cyprids were maintained in the same temperature regimes as ExperimentⅠfor 96 hours,but without providing algal food.The numbers of surviving individuals were recorded regularly as those that had settled.In ExperimentⅠ,the larval survival rates were 99.0%±1.2%(12°C),95.0%±4.8%(18°C),92.0%±2.8%(24°C),80.0%±10.6%(30°C),and 0(36°C),with the larvae developing fastest at 30°C,followed by 24°C,18°C and 12°C,based on the larval proportions at various stages.In ExperimentⅡ,the cypris survival rate was 100%at all designated temperatures;and although settlement occurred over a wide range of temperature(18~36°C),it was the highest at 30°C reaching 84.5%±12.1%.The statistical analysis indicated that there were significant differences in larval development and settlement between the group at 30°C and those at 12°C,18°C and 24°C.In general,it can be concluded that from 12°C to 30°C,the larval development and settlement were promoted by increasing temperature.Cyprids presented a better tolerance to high temperatures than nauplii.No nauplii survived at 36°C and no cyprids settled at 12°C.In considering the survival rate,development status and settlement percentage of the larvae,18~30°C should be the appropriate temperatures for larval development and settlement of the acorn barnacle A.reticulatus.