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    Genoveva Cerdenares

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    The sailfish Istiophorus platypterus is abundant in tropical coastal areas of the Pacific Ocean. It is targeted by both sport-fishing and commercial (artisanal) fleets in Mexico, Guatemala, Costa Rica, and Panama. The Gulf of Tehuantepec... more
    The sailfish Istiophorus platypterus is abundant in tropical coastal areas of the Pacific Ocean. It is targeted by both sport-fishing and commercial (artisanal) fleets in Mexico, Guatemala, Costa Rica, and Panama. The Gulf of Tehuantepec is one of the main areas of abundance of I. platypterus, where it is caught incidentally by artisanal vessels. The objective of this study was to analyze the size structure and the variability in the catch-per-unit-effort (CPUE) of sailfish caught in the Gulf of Tehuantepec from 2000 to 2008. The size structure was analyzed using eye-fork length (EFL) and CPUE was estimated as the number of individuals per fishing trip. Individuals ranged in size from 55 to 240 cm EFL and varied in total weight from 1.6 to 69.7 kg. The size structure was unimodal, and the variability over time showed a negative tendency (F(0.05(1),8,4967) = 6.8E + 8; P < 0.05). The CPUE of I. platypterus showed seasonal changes: values were lower from January to April and higher ...
    Euthynnus (family Scombridae) is a genus of marine pelagic fish species with a worldwide distribution that comprises three allopatric species: E. alletteratus, E. affinis and E. lineatus. All of them targeted by artisanal and commercial... more
    Euthynnus (family Scombridae) is a genus of marine pelagic fish species with a worldwide distribution that comprises three allopatric species: E. alletteratus, E. affinis and E. lineatus. All of them targeted by artisanal and commercial fisheries. We analyzed 263 individuals from Atlantic and Pacific Oceans using two genetic markers, the mtDNA Control Region (350 bp) and nuclear calmodulin (341 bp). The results obtained challenge the phylogeny of this group. We found a deep genetic divergence, probably at species level, within E. alletteratus, between the North Atlantic-Mediterranean and the Tropical East Atlantic. This deep genetic divergence was tested with several species delimitation methods. This complete phylogeographic association between the North Atlantic and the Tropical East Atlantic support the hypothesis of two cryptic species. In addition, population genetic heterogeneity was detected between the North East Atlantic–Mediterranean and North West Atlantic regions. Our re...
    ... Lista Sistemática de Peces de la Laguna del Mar Muerto, Oaxaca-Chiapas ... Batrachoides waltersi Collette y Russo, 1981 Familia Poeciliidae Poecilia sphenops Cuvier y Valenciennes, 1836 Poeciliopsis fasciata Meek, 1904 Familia... more
    ... Lista Sistemática de Peces de la Laguna del Mar Muerto, Oaxaca-Chiapas ... Batrachoides waltersi Collette y Russo, 1981 Familia Poeciliidae Poecilia sphenops Cuvier y Valenciennes, 1836 Poeciliopsis fasciata Meek, 1904 Familia Anablepidae Anableps dovii Gill, 1861 Familia ...
    ABSTRACT Quantitative histology was used to analyse the seasonal reproductive characteristics of the Istiophorus platypterus sailfish obtained from bycatch and recreational catches in the southeast Mexican Pacific. The analysis revealed... more
    ABSTRACT Quantitative histology was used to analyse the seasonal reproductive characteristics of the Istiophorus platypterus sailfish obtained from bycatch and recreational catches in the southeast Mexican Pacific. The analysis revealed five stages of ovarian development, eight kinds of oocytes, and one postovulation structure. The species shows an asynchronous ovary development and indeterminate fecundity. Gonadosomatic indices (GSI) indicated that sailfish have a reproductive period with peaks in September and October (mean monthly GSI=1.9 and 1.8). Females were more abundant during the second quarter, whereas males were more abundant in the third and fourth quarters. We found that the estimates of the frequency distribution of whole oocytes showed that this analysis may be useful as a tool to assess maturity. The estimated size at sexual maturity for this species in the Gulf of Tehuantepec was 150.2 cm eye–fork length.
    ABSTRACT Quantitative histology was used to analyse the seasonal reproductive characteristics of the Istiophorus platypterus sailfish obtained from bycatch and recreational catches in the southeast Mexican Pacific. The analysis revealed... more
    ABSTRACT Quantitative histology was used to analyse the seasonal reproductive characteristics of the Istiophorus platypterus sailfish obtained from bycatch and recreational catches in the southeast Mexican Pacific. The analysis revealed five stages of ovarian development, eight kinds of oocytes, and one postovulation structure. The species shows an asynchronous ovary development and indeterminate fecundity. Gonadosomatic indices (GSI) indicated that sailfish have a reproductive period with peaks in September and October (mean monthly GSI=1.9 and 1.8). Females were more abundant during the second quarter, whereas males were more abundant in the third and fourth quarters. We found that the estimates of the frequency distribution of whole oocytes showed that this analysis may be useful as a tool to assess maturity. The estimated size at sexual maturity for this species in the Gulf of Tehuantepec was 150.2 cm eye–fork length.
    El tiburón aleta de cartón Carcharhinus falciformis es una especie de importancia comercial y, pese a ello, el conocimiento de su historia de vida es limitado. El presente trabajo tiene como objetivo generar información sobre la edad y... more
    El tiburón aleta de cartón Carcharhinus falciformis es una especie de importancia comercial y, pese a ello,
    el conocimiento de su historia de vida es limitado. El presente trabajo tiene como objetivo generar información
    sobre la edad y el crecimiento de C. falciformis que se captura en la costa del estado de Oaxaca,
    México, a partir de la inferencia de multimodelos (imm). Este enfoque permite hacer estimaciones óptimas
    de los parámetros de crecimiento en situaciones de información limitada. Las muestras se obtuvieron de la
    pesca artesanal de tiburón en la costa chica de Oaxaca, de enero a noviembre de 2005. Para la descripción
    del crecimiento se contrastaron cuatro modelos; von Bertalanffy (de dos y tres parámetros), Gompertz y
    Schnute. Se utilizó el Índice de Información de Akaike (aicc) como criterio de selección. Se registraron
    421 organismos en un intervalo de tallas de 50 a 157 cm de longitud total (lt). La muestra para la determinación
    de edad consistió de 21 organismos (9 machos y 12 hembras), con longitudes de 50 a 157 cm
    de lt. La comparación de modelos y la inferencia a partir de imm basada en el criterio aicc mostraron que
    el modelo de Gompertz de dos parámetros resulta el mejor entre los candidatos contra la selección a priori
    del modelo de von Bertalanffy. Los parámetros estimados del modelo de Gompertz fueron l∞ = 185.4 cm,
    k = 0.264 años-1, utilizando una longitud de nacimiento de 65 cm de lt.
    Palabras clave: Pesca artesanal, inferencia multimodelos, información limitada, Tehuantepec
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