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.

Reproduction, distribution and abundance of the fish Pseudupeneus grandisquamis (Perciformes: Mullidae), in the Gulf of Tehuantepec, Mexico. As result of its biological and ecological strategies, Pseudupeneus grandisquamis is a dominant species in the demersal community of the Gulf of Tehuantepec, Mexico. Our main objective was to understand these strategies with respect to distribution, abundance and reproduction. We analyzed 5 175 individuals representing partial collections from five oceanographic expeditions between 1989 and 1990. It is a typical demersal marine species, with a wide distribution on the continental shelf. The highest abundance of P. grandisquamis occurs in March and November, around the 40 m isobath, facing the Superior-Inferior lake systems and Mar Muerto Lagoon. Reproduction occurred during all of the months studied, particularly from August to October, corresponding to the rainy season, when the salinity and temperature is lower. The presence of juveniles, principally in November and March, suggests a long period of recruitment; they are distributed mainly in the Superior-Inferior Lagoons, which serves as a nursery area where they remain until they are adults. The total female to male sex ratio was nearly 1:1 throughout the year. The maximum total length was 213 mm and the size at first maturity was 138 mm TL. The high abundance and reproduction occur when the gulf has a high level of ecological production, in accordance with the dynamics of the system, where the influence of coastal lagoons is important. Protection strategies for the area above the continental shelf of the Gulf of Tehuantepec are recommended for the estuary processes and for the reproduction and rearing of a large number of species, including P.

The ecological studieson the fish community in La Entrega Bay about its composition, diversity, distribution, and abundance7-288 Boletín de Investigaciones Marinas y Costeras • Vol. 46 (1) • 2017are 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 andApril 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 wasconducted by two divers and considering a field of view of 5 m. Ten transects were distributed in thefollowing way: five in the coral reef, three in the rocky reef, and two in the sandy bottom in front ofthe commercial area of the Bay. A total of 65 species, 49 genus and 28 families were identified. Themost representative families were Labridae, with nine species and five genera, Pomacentridae witheight species and four genera and Tetraodontidae with five species and three genera. The greatestabundance of fish was characteristic of the coral reef, mainly during the rainy season. The greatestdiversity and specific richness occurred on the rocky reef during the rainy season. The classificationanalysis 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. Stegastesacapulcoensis, Microspathodon dorsalis, C. atrilobata, Apogon pacificus and Halichoeres notospiluswere dominant species on the rocky reef. Haemulon maculicauda, Haemulon steindachneri, Mugilcurema and Mulloidichthys dentatus were dominant species on the sandy environment. The specificrichness has a direct relationship with temperature. The abundance variations during the five months ofsampling were statistically different.

Reproduction, distribution and abundance of the fish Pseudupeneus grandisquamis (Perciformes: Mullidae), in the Gulf of Tehuantepec, Mexico. As result of its biological and ecological strategies, Pseudupeneus grandisquamis is a dominant species in the demersal community of the Gulf of Tehuantepec, Mexico. Our main objective was to understand these strategies with respect to distribution, abundance and reproduction. We analyzed 5 175 individuals representing partial collections from five oceanographic expeditions between 1989 and 1990. It is a typical demersal marine species, with a wide distribution on the continental shelf. The highest abundance of P. grandisquamis occurs in March and November, around the 40 m isobath, facing the Superior-Inferior lake systems and Mar Muerto Lagoon. Reproduction occurred during all of the months studied, particularly from August to October, corresponding to the rainy season, when the salinity and temperature is lower. The presence of juveniles, principally in November and March, suggests a long period of recruitment; they are distributed mainly in the Superior-Inferior Lagoons, which serves as a nursery area where they remain until they are adults. The total female to male sex ratio was nearly 1:1 throughout the year. The maximum total length was 213 mm and the size at first maturity was 138 mm TL. The high abundance and reproduction occur when the gulf has a high level of ecological production, in accordance with the dynamics of the system, where the influence of coastal lagoons is important. Protection strategies for the area above the continental shelf of the Gulf of Tehuantepec are recommended for the estuary processes and for the reproduction and rearing of a large number of species, including P.

Cambios ambientales y tróficos a través de un análisis a largo plazo del sistema lagunar Chantuto-Panzacola, Chiapas, México RESUMENLa eutrofización es el proceso de enriquecimiento del agua por nutrientes, que estimula un incremento en la productividad primaria y frecuentemente está relacionado con las proliferaciones de algas nocivas y con las condiciones de hipoxia/anoxia. Este fenómeno, asociado al incremento de la presión antropogénica, se ha convertido en un problema de proporciones globales, por lo que se han realizado diversos esfuerzos para su detección y control. El presente estudio tuvo como objeto analizar la variación espacio-temporal del sistema estuarino Chantuto-Panzacola, tomando en cuenta registros de más de dos décadas anteriores (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009), y su condición fisicoquímica actual (2015)(2016). Se aplicaron y desarrollaron índices tróficos y ecológicos a las condiciones tropicales, así como su variación a lo largo del período de análisis. La cuantificación y el análisis de los parámetros fisicoquímicos e índices tróficos determinaron que existen cambios en su patrón anual a partir del 2008, denominados principalmente por los nitratos más nitritos. Sin embargo, en el último año se observó un mayor predominio del amonio. En todos los nutrientes, comparando poco más de 25 años, se obtuvieron concentraciones mayores en los últi-mos períodos, cuyas concentraciones aumentaron más del 90% su promedio anual. La aplicación de los índices tróficos corroboró un activo proceso de eutrofización a partir del año 2008, con énfasis en las lagunas de Chantuto, Cerritos y Panzacola, debido al constante aporte de nutrientes provenientes de los ríos adyacentes que contribuyen al aumento de nitrógeno y fósforo.Palabras claves: Eutrofización, lagunas costeras, nutrientes, fisicoquímico, Chiapas. ABSTRACTEutrophication is the enrichment of a water body with nutrients, thus fostering an increase in primary productivity; it is frequently related to proliferation of harmful algae blooms and hypoxia/anoxia conditions. Eutrophication and increased anthropogenic pressure have become a phenomenon of global proportions; consequently, efforts are currently underway for their detection and control. This paper analyses the spatial and temporal variation of the Chantuto-Panzacola estuarine system, based on records of more than two decades