Oldest estimated age for Sphyrna mokarran (Carcharhiniformes: Sphyrnidae) in the Mexican Pacific

The estimated age (around 45 years) from vertebral growth band counts for the largest Sphyrna mokarran caught in the Gulf of California and Central Mexican Pacific in the last decades, locates it as the oldest elasmobranch reported to date in Mexican Pacific waters. The specimen studied was a mature female of approximately 550 kg of total weight and 424 cm of total length, caught by artisanal fishermen using longlines south of the archipelago of Islas Marías on November 11th 2010. The distance between growth bands showed fast growth during the first 10 years. Growth bands after the age of 38 were only visible in the corpus calcareum, though difficult to separate and count. The age estimated in the present study was similar to the maximum age reported for the species in the Atlantic Ocean and Gulf of Mexico, confirming the species as long lived

Variación temporal de la captura de tiburón en las islas y costa central de Nayarit, México, con base en los registros oficiales de desembarque

Shark landings are not registered by species in Mexico, preventing their use for population assessments and fishery management. In the present study temporal variations of landings in the islands and central region of Nayarit are determined based in the official records, analyzing their usefulness and deficiencies. Total monthly catches were estimated by adding the landings of all shark categories registered in the San Blas Fisheries Office during 1992-2010. The seasonality of official landings was compared with the relative abundance of the main shark species registered during field samplings carried out during 2007-2011. Shark landings are registered using several categories, related to the diversity of species, common names and variety of products, making difficut its analysis. No significant differences were found among monthly total catches (ANOVA11, 224 F = 1.291, p > 0.05), but were found among the seasonal ones (ANOVA3, 224 F = 4.227, p< 0.01), being larger in winter than in spring and summer (monthly average catches per season = 19.24, 10.08  and 7.68 t, respectively). Contrary to the national tendency, the total annual catch in the region showed a positive trend during the last two decades (? de Kendall = 0.699, S = 107, p < 0.0001), with a peak during 2009 (605 t). Enforcement of the existing Mexican laws is urgent to develop a specific landing system, allowing its future use for population assessments and effective management measures development.Los desembarques de tiburón no son registrados de forma específica en México, limitando su uso en evaluaciones poblacionales y el manejo pesquero. En el presente estudio se determinaron las variaciones temporales en la captura de tiburón de las islas y costa central de Nayarit a partir de los registros oficiales, analizando su utilidad y deficiencias. Las capturas totales mensuales se estimaron mediante la suma de los desembarques de todas las categorías de tiburón-cazón registrados en la Oficina de Pesca de San Blas durante 1992-2010. La variación estacional de las capturas oficiales se comparó con la abundancia relativa de las principales especies de tiburón registradas en muestreos de campo realizados durante 2007-2011. Se encontró que los desembarques son registrados en numerosas categorías, relacionadas con la diversidad de especies, nombres comunes y presentación de productos, dificultando su análisis. No se encontraron diferencias significativas entre las capturas totales mensuales (ANDEVA11, 224 F = 1.291, p> 0.05), pero sí entre las estacionales (ANDEVA3, 224 F = 4.227, p< 0.01), siendo mayores en invierno que en primavera y verano (captura mensual promedio por estación = 19.24, 10.08 y 7.68 t, respectivamente). Contrario a la tendencia nacional, la captura anual de tiburón en la región mostró una tendencia positiva en las últimas dos décadas (? de Kendall = 0.699, S = 107, p< 0.0001), con un máximo en el año 2009 (605 t). Es urgente aplicar la normatividad existente en México para desarrollar el sistema de información de capturas por especie, permitiendo en un futuro su uso en evaluaciones poblacionales y el desarrollo de medidas efectivas de manejo

Estimation of the total, fork and precaudal lengths for the silky shark, Carcharhinus falciformis (Carcharhiniformes: Carcharhinidae), from the interdorsal length

The suitability of using the interdorsal length (IL) to estimate total (TL), fork (FL) and precaudal (PL) lengths of Carcharhinus falciformis in the Central Mexican Pacific (CMP) was analyzed. A linear model described adequately the relationships (TL = 3.974IL + 8.277, FL = 3.297IL + 6.561 and PL = 3.016IL + 4.814, r = 0.99 and p < 0.001 in all cases, n = 1196, 1162 and 1164 respectively). No significant differences between sexes were found for all the relationships (ANCOVA, p > 0.05 for all cases), but significant differences were found with both TL and PL estimated from IL with equations previously reported for the species in the South Eastern Pacific Ocean (t = -161.58, d.f. = 1199, p < 0.001 and t = -228.522, d.f. = 1168, p < 0.001 respectively). Such differences could be related to the short dimensions of IL, as discrepancies appeared to be larger in small organisms. Thus, measuring IL with the highest possible accuracy is recommended. IL is an alternative easy-to-take measure that allows estimation of sharks size when landed as carcass. The use of the present equations for C. falciformis from the CMP is recommended to standardize measurement methods, thereby allowing more reliable population comparisons based on shark size

Evaluación de riesgo ecológico de la pesca artesanal para los tiburones capturados en la entrada del Golfo de California

In Mexico sharks are an important fishery resource, however, their biological characteristics make them highly vulnerable to overfishing. In order to assess the vulnerability (v) and ecological risk (ER) of 20 species caught by the artisanal fishery at the entrance of the Gulf of California, a Productivity and Susceptibility Analysis (PSA) was performed taking into consideration the main fishing capture systems used in this region (gillnets and longlines). The results showed that thirteen species (65%) have medium biological productivity and the rest of them (35%) have low. The catch susceptibility was low to the total species analyzed. The ER estimated was high for seven species and medium for 13 of them. Likewise, all species were located in the medium category of vulnerability. The productivity values obtained for the species are comparable to those reported in similar research and confirm the considerable sensitivity of sharks to overfishing. Moreover the low susceptibility of capture in all species is related to the limited autonomy of the artisanal boats and and their operation range. The PSA is a rapid method applicable to fisheries that have insufficient information for traditional fisheries assessments and its application in other elasmobranch fisheries can help to delineate and prioritize fisheries management policies and research.En México los tiburones son un importante recurso pesquero, sin embargo, sus características biológicas los hacen altamente vulnerables a la sobrepesca. Con el propósito de evaluar el riesgo ecológico (RE) y la vulnerabilidad (?) por efectos de la pesca artesanal, se llevó a cabo un Análisis de Productividad y Susceptibilidad (APS) de 20 especies, que se capturan en la entrada del Golfo de California en función de los principales sistemas de captura (redes y palangres). Los resultados mostraron que trece especies (65%) tienen productividad biológica media y el resto de ellas (35%) baja. La susceptibilidad de captura resultó baja para el total de especies analizadas. El RE estimado fue alto para siete especies y medio para 13 de ellas. Asimismo, todas las especies se ubicaron en la categoría media de vulnerabilidad. Los valores de productividad obtenidos para las especies son equiparables a los reportados en investigaciones similares y confirman la considerable sensibilidad de los tiburones a la sobrepesca. Por otra parte, la baja susceptibilidad de captura en todas las especies se relacionó con la limitada autonomía de las embarcaciones artesanales y su radio de operación. El APS es un método rápido, aplicable a pesquerías que cuentan con información escasa para realizar evaluaciones pesqueras tradicionales y su aplicación en otras pesquerías de elasmobranquios ayudaría a delinear y priorizar políticas de manejo pesquero y de investigación

Hepatic undifferentiated embryonal sarcoma as a cause of acute abdomen

Primary liver sarcoma represents less than 1% of all primary liver tumors. Hepatic undifferentiated embryonal sarcoma (HUES) is included in the histologic group of primary liver sarcomas. HUES is a rare malignant liver tumor with a low incidence in the adult population. At moment there is no tumor marker that increases suspicion or diagnosis Early diagnosis is key to rise the possibilities of long-term survival. It has currently improved its prognosis through multidisciplinary management with surgical resection and chemotherapy. This case report presents a 20-year-old female patient with acute abdomen and anemic syndrome secondary to spontaneous rupture of a HUES requiring medical management initially based on resuscitation and arterial embolization with subsequent surgical resection

Opportunities and challenges in value chain analysis for sustainable management of sharks and rays

Studies on elasmobranch trade have often focused on a single commodity, shark fins. Such a narrow focus can result in an incomplete understanding of the socio-cultural importance of sharks, limiting discussion on the range and efficacy of potential management interventions. Assessments must be performed across the value chain from fisher to retail vendor to better conserve vulnerable elasmobranch species, offering a broader view of capture, use, and trade. Here, we collate insights from shark value chain assessments conducted in eight countries (Mexico, Peru, Guinea-Bissau, India, Bangladesh, Sri Lanka, Indonesia and Fiji) spanning five continents. Approaches and processes implemented in a shark value chain analysis (VCA) were reviewed to: (1) understand better approaches and tools and (2) collate shared experiences. Our results demonstrate that VCAs broaden the outlook of fishery and trade assessments when capturing a more comprehensive range of economic and socio-cultural aspects (e.g., livelihoods, cultural use of commodities) of trade in all shark commodities. Time invested in various components of assessments produced different outcomes, with considerable returns from stakeholder selection, survey design, and assessor/stakeholder relationship building. Contrastingly, results demonstrated that efforts in communication with stakeholder groups and policymakers could be further streamlined to focus on key results using a variety of communication formats. Outcomes from this study offer guidance to those embarking on shark VCAs, facilitating improving the assessment process and outcomes

Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 11

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 11, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR), Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTAG), Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kleber Ramírez (UPTM), Mérida – Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (C.A.B.B.O.P.P), Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE), Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia - Venezuela, Centro de Investigaciones Internacionales SAS (CIN), Antioquia - Colombia.y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

Gestión del conocimiento. Perspectiva multidisciplinaria. Volumen 8

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, volumen 8, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada de acceso abierto a todas las áreas del conocimiento, que cuenta con el esfuerzo de investigadores de varios países del mundo, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico que consoliden la transformación del conocimiento en diferentes escenarios, tanto organizacionales como universitarios, para el desarrollo de habilidades cognitivas del quehacer diario. La gestión del conocimiento es un camino para consolidar una plataforma en las empresas públicas o privadas, entidades educativas, organizaciones no gubernamentales, ya sea generando políticas para todas las jerarquías o un modelo de gestión para la administración, donde es fundamental articular el conocimiento, los trabajadores, directivos, el espacio de trabajo, hacia la creación de ambientes propicios para el desarrollo integral de las instituciones