Lanés L E K, Godoy R S, Maltchik L, Polačik M, Blažek R, Vrtílek M, Reichard M
Laboratório de Ecologia e Conservação de Ecossistemas Aquáticos-LECEA, Universidade do Vale do Rio dos Sinos-UNISINOS, Bairro Cristo Rei, São Leopoldo, Rio Grande do Sul, Brazil.
Instituto Pró-Pampa-IPPAMPA, Bairro Centro, Pelotas, Rio Grande do Sul, Brazil.
J Fish Biol. 2016 Nov;89(5):2345-2364. doi: 10.1111/jfb.13122. Epub 2016 Sep 8.
Seven ephemeral pools on the coastal plain of southern Brazil were found to be inhabited by three annual and 22 non-annual fish species. Two common annual species (Austrolebias minuano and Cynopoecilus fulgens) exhibited clear seasonal dynamics, with the appearance of young fishes in the austral autumn (May to June) and a decline in abundance over the seasonal cycle. The third annual species, Austrolebias wolterstorffii, was rare. No seasonal dynamics were observed in non-annual fishes. The relative abundance of non-annual fishes compared with annual fishes increased over the seasonal cycle, but they coexisted widely. The size structure of annual fishes suggested the presence of a single age cohort in most pools though a second age cohort was registered in one pool in August, coinciding with a large flooding. Strong sexual dimorphism in body size was found in C. fulgens throughout the seasonal cycle, while no sexual dimorphism in body size was found in A. minuano. Female-biased sex ratios were recorded in both common annual fish species in the last three sampling dates (in spring), but not during the first two sampling dates (in winter). The natural lifespan of annual fishes was <8 months. Annual fishes disappeared before habitat desiccation in half of the pools, while non-annual fishes were still present.
在巴西南部沿海平原发现的七个临时水塘中，栖息着三种一年生鱼类和22种非一年生鱼类。两种常见的一年生鱼类（米氏澳鳉和亮尾犬齿鳉）呈现出明显的季节性动态，幼鱼在南半球秋季（5月至6月）出现，且在季节性周期内数量减少。第三种一年生鱼类沃氏澳鳉很罕见。非一年生鱼类未观察到季节性动态。在季节性周期内，非一年生鱼类相对于一年生鱼类的相对丰度有所增加，但它们广泛共存。一年生鱼类的大小结构表明，大多数水塘中存在单一的年龄组，不过在8月的一个水塘中记录到了第二个年龄组，这与一次大洪水同时发生。在整个季节性周期中，亮尾犬齿鳉在体型上存在明显的两性异形，而米氏澳鳉在体型上未发现两性异形。在最后三个采样日期（春季），两种常见的一年生鱼类都记录到了偏雌性的性别比例，但在前两个采样日期（冬季）没有。一年生鱼类的自然寿命小于8个月。在一半的水塘中，一年生鱼类在栖息地干涸前就消失了，而非一年生鱼类仍然存在。
