FISH COMMUNITY STRUCTURE IN LA ENTREGA BAY, OAXACA, MEXICO.

Abstract

The ecological studies
on the fish community in La Entrega Bay about its composition, diversity, distribution, and abundance
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8 Boletín de Investigaciones Marinas y Costeras • Vol. 46 (1) • 2017
are insufficient, although it has one of the largest structured coral reef, with a variety of environments,
habitats, and aquatic organisms poorly studied. Five samples were made in November 2002, March and
April 2003, which correspond to the dry season; and June and August 2003 during the rainy season,
through visual censuses with band transects of 10 m long and parallel to coastline. Each census was
conducted by two divers and considering a field of view of 5 m. Ten transects were distributed in the
following way: five in the coral reef, three in the rocky reef, and two in the sandy bottom in front of
the commercial area of the Bay. A total of 65 species, 49 genus and 28 families were identified. The
most representative families were Labridae, with nine species and five genera, Pomacentridae with
eight species and four genera and Tetraodontidae with five species and three genera. The greatest
abundance of fish was characteristic of the coral reef, mainly during the rainy season. The greatest
diversity and specific richness occurred on the rocky reef during the rainy season. The classification
analysis indicates a different community structure for coral reef, rocky, and sandy environments.
Thalassoma lucasanum, Stegastes acapulcoensis, Prionurus punctatus, Chromis atrilobata,
Haemulon maculicauda and Chaetodon humeralis were dominant species on the coral reef. Stegastes
acapulcoensis, Microspathodon dorsalis, C. atrilobata, Apogon pacificus and Halichoeres notospilus
were dominant species on the rocky reef. Haemulon maculicauda, Haemulon steindachneri, Mugil
curema and Mulloidichthys dentatus were dominant species on the sandy environment. The specific
richness has a direct relationship with temperature. The abundance variations during the five months of
sampling were statistically different.