Velázquez-Velázquez Ernesto, Vega-Cendejas M Eugenia, Navarro-Alberto Jorge
Escuela de Biología, Universidad de Ciencias y Artes de Chiapas, Libramiento Norte Poniente s/n, Tuxtla Gutiérrez, Chiapas, México.
Rev Biol Trop. 2008 Jun;56(2):557-74. doi: 10.15517/rbt.v56i2.5608.
Composition and abundance of the ichthyofauna in estuarine and coastal lagoon systems of the South Pacific in Mexico have been scarcely studied. In particular, there is a lack of information on how environmental variables determine the spatio-temporal structure of fish assemblages in those habitats. In this study, fishes were sampled by drop net during twelve months (May 2004 - April 2005) in 22 sites distributed along the Carretas-Pereyra lagoon, located in the Biosphere Reserve La Encrucijada, Chiapas, Mexico. We recorded 11,797 individuals (40 species, in 30 genera and 21 families). Dormitator latifrons was the most dominant species in terms of the Importance Value index, IV (23.05%), followed by Lile gracilis (10.31%), Poecilia sphenops (8.60%) and Poecilia butleri (7.30%). D. latifrons also accounted for more than one half of the total biomass (50.14%). Species richness and Shannon-Wiener's diversity indexes showed similar temporal fluctuations, reaching their highest values during the dry season. The system evidenced temporal variations in salinity, having observed four different regimes: freshwater, oligohaline, mesohaline and polyhaline. Mean richness and diversity indexes achieved their highest values during the mesohaline period. On the other hand, mean abundances (CPUE) were highest during the freshwater period. Canonical correspondence analysis (CCA) indicated that salinity and temperature were the most important environmental parameters affecting associations of fishes in terms of their abundances. Correlation analyses revealed that among the environmental variables measured in this study, transparency showed the most significant negative correlation with fish richness and Shannon-Wiener's diversity index. At a local scale, results suggest that spatial and temporal distribution of fish assemblages are determined by differences in the regimes of salinity and transparency, primarily driven by freshwater input from rivers.
墨西哥南太平洋河口和沿海泻湖系统中鱼类区系的组成和丰度鲜有研究。特别是，缺乏关于环境变量如何决定这些栖息地鱼类群落时空结构的信息。在本研究中，于2004年5月至2005年4月的十二个月期间，在墨西哥恰帕斯州拉恩克鲁西阿达生物圈保护区内沿卡雷塔斯 - 佩雷拉泻湖分布的22个地点，用落网对鱼类进行采样。我们记录了11,797个个体（40种，分属30属21科）。就重要值指数（IV）而言，宽额眠鱼是最主要的物种（23.05%），其次是细纹丽脂鲤（10.31%）、食蚊鱼（8.60%）和巴氏食蚊鱼（7.30%）。宽额眠鱼还占总生物量的一半以上（50.14%）。物种丰富度和香农 - 维纳多样性指数显示出相似的时间波动，在旱季达到最高值。该系统显示出盐度的时间变化，观察到四种不同状态：淡水、低盐、中盐和高盐。平均丰富度和多样性指数在中盐期达到最高值。另一方面，平均丰度（CPUE）在淡水期最高。典范对应分析（CCA）表明，就鱼类丰度而言，盐度和温度是影响鱼类群落的最重要环境参数。相关分析表明，在本研究测量的环境变量中，透明度与鱼类丰富度和香农 - 维纳多样性指数呈现最显著的负相关。在局部尺度上，结果表明鱼类群落的时空分布由盐度和透明度状态的差异决定，主要受河流淡水输入驱动。
