Stomach contents and dietary overlap of three round stingray species (Urobatis halleri, Urotrygon munda, and Urotrygon rogersi) captured off the central Pacific coast of Mexico were analyzed during the two main hydroclimatic periods (T1 and T2) that characterize the environmental variability in the area. The three round stingray species showed a narrow bathymetric distribution range, and the highest abundances were located at 20 m depth in both seasons. In general, the diets were mainly composed of benthic microcrustaceans (caridean shrimps) and to a lesser extent of fishes, polychaetes, and molluscs. The most abundant prey items in the diets were carideans of the families Processidae and Ogyriididae, and penaeids, followed by brachyuran and stomatopod larvae. All three stingrays exhibited a generalist feeding strategy. The diets showed high overlap values during period T1 in both inter- and intraspecies analyses, but lower values during period T2. There was no evidence of ontogenetic diet changes and sex was not a factor for trophic differences. The slight differences among diets were due to seasonal changes in the soft-bottom macrobenthic invertebrate assemblages in the shallow waters, and relationships like predation and competition were not the main factors influencing the population dynamics of the three stingray species.

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Weight-length relationships are reported for 38 species of teleost fish belonging to 20 families. Data were collected on a regular basis from February 2011 to January 2012 in the Barra de Navidad coastal lagoon, Jalisco, Mexico. Several different types of sampling gear were used to obtain a broad range of fish lengths. These are the first records in FishBase regarding weight-lengths for eight of the species. U.S.

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RESUMEN. La lisaMugil curema tiene amplia distribución en América, habitando sistemas costeros y estuarinos. Es un recurso con importancia pesquera en varias regiones del Pacífico mexicano. El objetivo del presente trabajo es describir aspectos reproductivos de M. curema durante un ciclo anual. Se realizaron muestreos mensuales con redes y atarraya de febrero 2011 a enero 2012 en la Laguna Barra de Navidad, Jalisco, México. Se analizaron 495 ejemplares, a los cuales se les midió la longitud y el peso total. De cada ejemplar se extrajeron las gónadas, se pesaron, clasificaron según su maduración y se procesaron para histología. Se capturaron ejemplares entre 10,3 y 38,5 cm, con promedio de 26,1 cm. Se identificaron 375 hembras con promedio de 27,2 cm y 110 machos con promedio de 23,4 cm. El número de hembras dominó de manera significativa en la muestra total, por mes y por clase de longitud. Los valores máximos del índice gonadosomático ocurrieron en abril, agosto y noviembre. El factor de condición presentó valores altos en varios meses coincidiendo en ambos sexos. En la ovogénesis se identificaron seis fases de desarrollo de los ovocitos y debido a la gran cantidad de ovocitos con crecimiento primario y en vitelogénesis 2 y 3, el patrón de desarrollo fue sincrónico por grupos con desove total. La longitud promedio de madurez (L50) de machos fue de 21,7 cm y de hembras de 24,5 cm. Contrastando estas dos últimas longitudes con las de captura, se sugiere que más del 50% de los organismos capturados son individuos que se reprodujeron al menos una vez. Palabras clave: Mugil curema, lisa, índice gonadosomático, histología, madurez gonadal, México. Reproductive aspects of Mugil curema (Mugiliformes: Mugilidae) in the Barra deNavidad coastal lagoon, Jalisco, Mexico ABSTRACT. The white mullet Mugil curema is broadly distributed in America inhabiting coastal and estuarine systems. It is an economically important fishery resource in several regions of the Mexican Pacific. The goal of this research was the description of several reproductive aspects of Mugil curema during an annual cycle. Fish were sampled monthly with gill and cast nets from February 2011 to January 2012 in the coastal lagoon Barra de Navidad, Jalisco, Mexico. A total of 495 fish were analyzed. Total length and weight were measured for each specimen and gonads were collected, weighted, classified after their maturation stage and preserved for histological analyses. Caught fish were between 10.3 and 38.5 cm total length with a mean of 26.1 cm. A total of 375 individuals were classified as females with a mean total length of 27.2 cm while 110 fish were classified as males with a mean total length of 23.4 cm. Females dominated by numbers in the total sample, monthly and by length classes. Highest values of the gonadosomatic index occurred in April, August and November. Condition factor showed high values in several months and its trend along the year was similar in both sexes. Six stages were identified during the oogenesis and, due to the high quantity of p...