Spatial, diel, and seasonal changes in the fish community structure of a Mexican tropical estuary

R Zárate-Hernández,L Sanvicente–Añorve,S Ortiz–Burgos,M Castillo–Rivera

doi:10.7773/cm.v38i4.2018

R Zárate-Hernández, L Sanvicente–Añorve + Show 2 more

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https://doi.org/10.7773/cm.v38i4.2018

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Abstract

To extend our knowledge about spatial and temporal variations in the structure of estuarine fish communities, diel samplings (collections every 2 h) were carried out every two months over a one-year period in two different habitats (vegetated and nonvegetated). We collected a total of 34,766 individuals, corresponding to 72 species, most of them with marine and tropical affinities. Species richness was significantly higher in the vegetated habitat, whereas abundance (number of fish) was higher in the nonvegetated habitat. The diel pattern of abundance showed peaks at dusk and dawn, whereas richness was higher at night. Seasonally, fish abundance and species richness showed peaks during January, March, and July–September, and these peaks were related to the entry of temperate species, production processes in the system, and rainfall pattern. Fish assemblages showed significant differences among habitats, day/night, and months. In the vegetated habitat, Lagodon rhomboides, Menidia beryllina, and Orthopristis chrysoptera were the predominant species. Microphagus species such as Brevoortia gunteri, Brevoortia patronus, and Mugil curema were predominant during the warm, dry season (March–May) and they were more abundant during the day. In contrast, predatory species such as Citharichthys spilopterus and Opsanus beta were more abundant during the rainy season and their capture was higher at night. The two most numerically abundant species, Anchoa mitchilli and Membras martinica, showed a twilight pattern, with abundance peaks at dusk and dawn, respectively. Hence, in Pueblo Viejo Lagoon (Mexico), the spatiotemporal changes in species composition are in part related to predator avoidance and feeding strategies, through a coupling of life histories with the diel and seasonal variation in the availability of resources, the presence of submerged vegetation playing an important role in this dynamic.

Highlights

Ichthyofauna comprises a significant portion of estuarine communities and its ecological and fisheries relevance is considerable
Diel changes in fish abundance and species composition have been primarily attributed to variations in foraging activity and predator avoidance (Layman 2000, Nagelkerken et al 2000, Pessanha and Araújo 2003, Pessanha et al 2003, Hagan and Able 2008), and are generally modulated by the tide and photoperiod (Layman 2000, Ribeiro et al 2006)
Previous studies have observed a considerable increase in the number of species during the night and for this reason nocturnal surveys are considered to provide better knowledge of the fish community structure (Griffiths 2001, Castillo-Rivera et al 2005, Hagan and Able 2008)

Summary

Introduction

Ichthyofauna comprises a significant portion of estuarine communities and its ecological and fisheries relevance is considerable. Many studies have addressed the variability of fish communities in structurally complex environments, such as habitats with submerged vegetation (Lubbers et al 1990, Kanouse et al 2006, Ribeiro et al 2006). Submerged vegetation provides diverse fish species better protection against predation and a greater amount of food due to the large number of small invertebrates that it shelters (Lubbers et al 1990, Heithaus 2004, Kopp et al 2007). Previous studies have observed a considerable increase in the number of species during the night and for this reason nocturnal surveys are considered to provide better knowledge of the fish community structure (Griffiths 2001, Castillo-Rivera et al 2005, Hagan and Able 2008). The seasonal variation of fish communities in estuaries can be regulated, synergistically or individually, by fluctuations in environmental conditions (Methven et al 2001, Castillo-Rivera et al 2002, Pessanha and Araújo 2003, Meynecke et al 2006), and by biotic factors such as recruitment and spawning patterns, trophic response, and resource partitioning (Pessanha et al 2003, Madurell et al 2004, Ribeiro et al 2006, CastilloRivera et al 2010)

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