Ichthyofauna in an ecological station in the Pantanal of Brazil: the hydrological cycle affecting species composition

This research aims to describe the ichthyological fauna in the area surrounding the Taiamã Ecological Station in the state of Mato Grosso, Brazil. Three expeditions were carried out, in September 2014, February 2015 and May/2015, in seasons ranging from the hydrological conditions of high waters (flood), low waters (drought), and decreasing waters (ebbing). During the research we sampled 3,664 individuals from six orders, 28 families and 78 species. Characiformes was the most abundant order (̴ 81 % of individuals), followed by Siluriformes (̴ 13 % of individuals), and Gymnotiformes (̴ 4 % of individuals). The most representative species were Moenkhausia dichroura (Kner, 1858), Serrapinus calliurus (Boulenger, 1900), Odontostilbe pequira (Steindachner, 1882) and Pimelodella gracilis (Valenciennes, 1840). The dry period showed the highest abundance (1541 individuals), richness (61 species), diversity (H’ = 2.69) and equitability (J’ = 0.65). These results fill a gap concerning species composition in the Pantanal, mainly referring to data available on Conservation Unit, and its surroundings. Moreover, this research provides a database to update the checklist of fish species in a remote wetland, offering a tool for management and conservation.

本研究旨在阐述巴西马托格罗索州泰亚玛生态站周边的鱼类生物群落。研究过程中共进行了三次探险，分别于2014年9月、2015年2月及2015年5月进行，涵盖了从洪水（高水位）、干旱（低水位）到水位下降（退水）的各个水文季节。在研究期间，我们从六个目、28个科和78个物种中采集了3,664个样本。其中，辐鳍鱼目（Characiformes）是数量最丰富的目（个体占比约81%），其次是鲇形目（Siluriformes，个体占比约13%），以及电鳗目（Gymnotiformes，个体占比约4%）。最具代表性的物种包括Moenkhausia dichroura（Kner, 1858）、Serrapinus calliurus（Boulenger, 1900）、Odontostilbe pequira（Steindachner, 1882）和Pimelodella gracilis（Valenciennes, 1840）。在干旱期间，物种的丰度（1541个个体）、物种丰富度（61种）、多样性（H’ = 2.69）和均匀度（J’ = 0.65）均达到最高。这些结果填补了关于潘塔纳尔地区物种组成的空白，特别是关于保护单位及其周边的数据。此外，本研究还提供了一份数据库，用于更新偏远湿地中鱼类物种的清单，为管理和保护提供了有力工具。