Distribution, growth and reproduction of the limpet Nacella (Patinigera) concinna (Strebel 1908) in relation to potential food availability, in Esperanza Bay (Antarctic Peninsula)
Distribution, growth and reproduction of the limpet Nacella (Patinigera) concinna (Strebel 1908) in relation to potential food availability, in Esperanza Bay (Antarctic Peninsula)
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埃斯佩兰萨湾（南极半岛）帽贝 Nacella (Patinigera) concinna (Strebel 1908) 的分布、生长和繁殖与潜在食物供应的关系
作者：
J. Brêthes;G. Ferreyra;S. Vega
本研究探讨了环境因素（结冰、水温、食物供应）对南极半岛一个海湾中帽贝Nacella (Patinigera) conconna生态的影响。1987年2月至1988年1月在潮间带、5米、10米三个深度取样。记录了温度，并测量了底部、水中和冰水层中叶绿素a的浓度。对帽贝进行测量、称重，并计算体质量和性腺质量的条件系数。通过尺寸频率分布分析和季节性von Bertalanffy生长模型估计它们的年龄。潮间带亚群在结冰季节开始时迁移到较深的水平，在冰消退后重新定居在潮间带。生长速率很低（von Bertalanffy K≈0.08）。生长速率表现出重要的季节变化，在12月和1月达到最大值。幼藻一年产卵一次，产卵时间与水温升高（从-1.33°C上升到0.84°C）一致，也可能与春季食物供应增加有关。在微底栖植物高存量时期，体质量增加，表明冰藻和浮游植物在埃斯佩朗萨湾作为帽贝食物来源的重要性较小。
The present work addresses the effect of environmental factors (icing, water temperature, food availability) on the ecology of the patellid limpet Nacella (Patinigera) concinna, in a bay on the Antarctic Peninsula. Sampling was conducted at three depths (intertidal, 5m, 10m) from February 1987 to January 1988. Temperature was recorded and concentrations of Chlorophyll a were measured on the bottom, in the water and in the ice-water layer. The limpets were measured, weighed and a condition coefficient for somatic and gonadal mass was calculated. Their ages were estimated through size frequency distribution analysis and a seasonalized von Bertalanffy growth model was applied. The intertidal subpopulation migrated to deeper levels at the beginning of the icing season and recolonized the intertidal zone after ice retreat. The growth rate was very low (von Bertalanffy K ≈ 0.08). Growth rates showed important seasonal variations, with maxima during December and January. Nacella (P.) concinna spawns once a year and spawning coincided with raising water temperature (from -1.33°C to-0.84°C), and probably was also related to increasing spring food availability. Body mass increased during periods of high standing stock of microphytobenthos, revealing that ice-algae and phytoplankton were of minor importance as food sources for limpets in Esperanza Bay.