Copatti C E, Legramanti R P, Trevisan A, Santos S
Programa de Pós-graduação em Diversidade Animal, Instituto de Biologia, Universidade Federal da Bahia - UFBA, Campus de Ondina, Rua Barão de Geremoabo, 147, CEP 40170-290, Salvador, BA, Brazil.
Programa de Pós-graduação em Biodiversidade Animal, Universidade Federal de Santa Maria - UFSM, Avenida Roraima, 1000, Cidade Universitária, Camobi, CEP 97105-900, Santa Maria, RS, Brazil.
Braz J Biol. 2016 Oct-Dec;76(4):1035-1042. doi: 10.1590/1519-6984.07815. Epub 2016 May 6.
In the current study, we investigated population aspects of Aegla georginae in the Ibicuí River Basin by considering different capture methods and the implication of these data in the analysis of population dynamics. We sampled 1774 individuals: 1259 males (21 and 97 juveniles and 1029 and 113 adults in trap and handnet, respectively), 512 females (05 and 140 juveniles, 184 and 64 adults, and 81 and 38 ovigerous in trap and handnet, respectively) and 03 unsexed individuals (02 and 01 in trap and handnet, respectively). The frequency distribution in size classes shows a bimodal model for both sexes. The carapace length (CL) in males and females varied from 3.11 to 26.00 and 3.73 to 22.36 mm, respectively. Males presented significantly larger sizes than females. The relative abundance between males and females was significantly different from 1:1 with more males than females in most sampling periods (p < 0.05) when considering the grouped data (handnet + trap) and trap captures, but followed the expected ratio in most months when considering individuals sampled only with handnet (p > 0.05). Juveniles were recorded in all seasons, and reproduction occurs throughout the year. The population structure is similar to the model known for aeglids, and the capture methods affected the analysis of A. georginae, where the grouped data and trap captures presented greater abundance of individuals than handnet and males predominate in the larger size classes, and females in the intermediary size classes. Therefore, an integrated view of the capture methods is the best model for studying the population dynamics of aeglids.
在本研究中，我们通过考虑不同的捕获方法以及这些数据在种群动态分析中的意义，对伊比奎河流域的乔治溪蟹种群特征进行了调查。我们共采集了1774只个体：1259只为雄性（陷阱捕获和手抄网捕获中分别有21只和97只幼体，1029只和113只成体），512只为雌性（陷阱捕获和手抄网捕获中分别有5只和140只幼体，184只和64只成体，81只和38只抱卵雌蟹），还有3只未区分性别的个体（陷阱捕获和手抄网捕获中分别有2只和1只）。大小类别的频率分布显示，两性均呈现双峰模型。雄性和雌性的头胸甲长度（CL）分别在3.11至26.00毫米和3.73至22.36毫米之间变化。雄性个体的体型明显大于雌性。当考虑汇总数据（手抄网 + 陷阱）和陷阱捕获时，大多数采样期内雄性和雌性的相对丰度显著不同于1:1，雄性多于雌性（p < 0.05），但在考虑仅通过手抄网采样的个体时，大多数月份遵循预期比例（p > 0.05）。各个季节均记录到了幼体，且全年都有繁殖现象。种群结构与已知的溪蟹模型相似，捕获方法影响了对乔治溪蟹的分析，汇总数据和陷阱捕获显示的个体丰度高于手抄网，且在较大尺寸类别中雄性占主导，中间尺寸类别中雌性占主导。因此，综合考虑捕获方法是研究溪蟹种群动态的最佳模型。
