Spatial and temporal variation of fish assemblages in a coastal lagoon of the Biosphere Reserve La Encrucijada, Chiapas, Mexico

Abstract

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. Rev.

Fish assemblage structure in relation to environmental conditions in a tropical estuary

“…If this is the case, phosphate concentrations may be responsible for the abundance and biomass spatial patterns observed in Sabancuy Estuary. This is contrary to previous reports for tropical estuaries in which salinity is the main controlling factor for estuarine fauna abundance and biomass (Díaz-Ruíz et al 2004, Velázquez-Velázquez et al 2008. This apparently does not hold true for Sabancuy Estuary, even though it has a slightly hyperhaline behavior.…”

Length-weight relationships for 24 fish species in a coastal lagoon of the Mexican South Pacific

“…The aim of this work was to determine length–weight relationships for 24 fish species in the Carretas‐Pereyra lagoon, a RAMSAR site on the Mexican Pacific coast, which includes 55 estuarine and marine fish species (Velázquez‐Velázquez et al., 2008).…”

The influence of habitat on the spatio-temporal dynamics of fish assemblages in a lagoon-estuarine system of the Mexican Pacific

“…The specific richness in the LJB system (48 species) was higher than that described in other ecological studies carried out in the Gulf of Tehuantepec. In the southern Gulf, richness varied between 31 species in the Chantuto-Panzacola system (Díaz-Ruiz et al, 2004) and 40 in Carretas-Pereyra (Velázquez-Velázquez et al, 2008). However, in the first case, comparisons between the fish assemblages should be taken with caution, due to the difference in the sampling effort and method.…”

“…Some of the dominant species found in the lagoon and the channel are secondary freshwater and estuarine residents (e.g., Dormitator latifrons and Astatheros macracanthus). The distribution and population structure of this group are determined by a temporal pattern affecting hydrological conditions (Díaz-Ruiz et al, 2004;Velázquez-Velázquez et al, 2008). During the rains, larger organisms were found in the channel, while juveniles of these species occurred in the lagoon during the pre-dry and dry seasons, suggesting a local migration from the streams to mesohaline environments.…”