Revista Chilena de Historia Natural 80 (4): 419-430, 2007
RESEARCH ARTICLE
Fish community structure in San Agustín Bay, Huatulco, Mexico
San Agustín bay is one of the most important bays in the Huatulco National Park because
it includes the broadest coral reef surface of this park, which supports a great diversity of fish species. The importance of the present
work is that describes quantitatively, for first time, the fish assemblage of this reef area. Visual censuses were realized on transects,
according to the coral reef size, on coral and rocky reefs, and coral rubble environments. 64 species, 46 genus and 29 families were
registered. Seasonal variation in fish assemblage was observed; reflecting the influence of pelagic shoaling species associated with
the Gulf of Tehuantepec upwelling, during the dry season. Thus species were Selar crumenophthalmus, Caranx
caninus, and Sardinops caeruleus. For species more closely associated to the reef habitat little
seasonal variation was observed for each species, except Chromis atrilobata, which exhibited high density during the dry
season. Pomacentrids exhibited more affinity for coral reef, labrids and haemulids for coral rubble environments. The highest diversity
values were on coral rubble and the highest density was on the coral reef. Our study suggests that in this region, the Gulf of
Tehuantepec upwelling is an important factor as well as the heterogeneity of habitats in shaping the fish assemblages, which must be
protected to maintain the biodiversity of this important ecosystem.
Key words:
Huatulco National Park,
coral reef, diversity, density, community
