Growth patterns and population dynamics of Chiton articulatus (Mollusca: Polyplacophora): A multi-decade study.

The edible chiton Chiton articulatus is a commercially important mollusk found in the rocky intertidal zones of the Mexican tropical Pacific. Despite the intense harvesting in Acapulco Bay, Mexico, knowledge of its growth patterns is limited, hindering the development of effective management strategies. This study investigated the growth dynamics of C. articulatus using a multi-model inference approach based on size structure data collected in four sampling periods covering four decades. Results revealed continuous recruitment throughout the year, contributing to population resilience. The species exhibited growth plasticity, highlighting its adaptive potential. We found complex temporal patterns influenced mainly by climatic events. The El Niño event sowed higher growth rates and lower asymptotic length, while La Niña events showed the opposite pattern. This research provides insights into the growth dynamics of C. articulatus, highlighting the need for holistic management strategies for this commercially important species in the face of environmental change.

First Record of Culicoides Occidentalis in Sinaloa, Mexico.

Culicoides species adults were collected in light traps located on the coast of Elota, Sinaloa, Mexico, in February 2022. All specimens were females, and it was determined based on their morphology that they belonged to the Culicoides variipennis complex. The identification of the species was carried out by means of a comparative analysis of genetic sequences of the cytochrome c oxidase subunit I gene, which resulted in C. occidentalis, this being its first report in Sinaloa and its third nationwide.

Implementation of control measures against an outbreak due to Clostridioides difficile producing toxin B in a tertiary hospital in Mexico.

INTRODUCTION: To describe the outbreak of Clostridioides difficile infection (CDI), and the impact of the prevention and control measures that were implemented in the "Hospital Juárez de México" (HJM) for its control. METHODS: A cross-sectional, descriptive, observational, and retrospective study was designed. All information on the hospital outbreak and on health care-associated infections (HCAI) was obtained from the files of the Hospital Epidemiological Surveillance Unit (HESU) of the HJM. RESULTS: A total of 15 cases of CDI were detected from February 20th to May 22nd, 2018, which represented 55.6% and 44.4% for the male and female gender, respectively, with an average age of 56 years and a range of 24 to 86 years old. It was possible to identify six failures and deficiencies that involved health personnel and hospital logistics through analyses based on the situational diagnosis in the services involved and through the construction of cause-effect diagrams. Additionally, through the detection of the outbreak by means of laboratory tests and timeline, the HESU team implemented measures and prospective surveillance to control and prevent the emergence of new cases. CONCLUSIONS: The implementation of basic quality tools, control measures, and the prospective epidemiological surveillance had a positive impact on the control against the outbreak of C. difficile producing toxin B.

Glycan Array Technology.

Glycan (or carbohydrate) arrays have become an essential tool in glycomics, providing fast and high-throughput data on protein-carbohydrate interactions with small amounts of carbohydrate ligands. The general concepts of glycan arrays have been adopted from other microarray technologies such as those used for nucleic acid and proteins. However, carbohydrates have presented their own challenges, in particular in terms of access to glycan probes, linker attachment chemistries and analysis, which will be reviewed in this chapter. As more and more glycan probes have become available through chemical and enzymatic synthesis and robust linker chemistries have been developed, the applications of glycan arrays have dramatically increased over the past 10 years, which will be illustrated with recent examples.

Self-Assembling Peptides as an Emerging Platform for the Treatment of Metabolic Syndrome.

Metabolic syndrome comprises a cluster of comorbidities that represent a major risk of developing chronic diseases, such as type II diabetes, cardiovascular diseases, and stroke. Alarmingly, metabolic syndrome reaches epidemic proportions worldwide. Today, lifestyle changes and multiple drug-based therapies represent the gold standard to address metabolic syndrome. However, such approaches face two major limitations: complicated drug therapeutic regimes, which in most cases could lead to patient incompliance, and limited drug efficacy. This has encouraged scientists to search for novel routes to deal with metabolic syndrome and related diseases. Within such approaches, self-assembled peptide formulations have emerged as a promising alternative for treating metabolic syndrome. In particular, self-assembled peptide hydrogels, either as acellular or cell-load three-dimensional scaffoldings have reached significant relevance in the biomedical field to prevent and restore euglycemia, as well as for controlling cardiovascular diseases and obesity. This has been possible thanks to the physicochemical tunability of peptides, which are developed from a chemical toolbox of versatile amino acids enabling flexibility of designing a wide range of self-assembled/co-assembled nanostructures forming biocompatible viscoelastic hydrogels. Peptide hydrogels can be combined with several biological entities, such as extracellular matrix proteins, drugs or cells, forming functional biologics with therapeutic ability for treatment of metabolic syndrome-comorbidities. Additionally, self-assembly peptides combine safety, tolerability, and effectivity attributes; by this presenting a promising platform for the development of novel pharmaceuticals capable of addressing unmet therapeutic needs for diabetes, cardiovascular disorders and obesity. In this review, recent advances in developing self-assembly peptide nanostructures tailored for improving treatment of metabolic syndrome and related diseases will be discussed from basic research to preclinical research studies. Challenges facing the development of approved medicinal products based on self-assembling peptide nanomaterials will be discussed in light of regulatory requirement for clinical authorization.

Genomic study of dilated cardiomyopathy in a group of Mexican patients using site-directed next generation sequencing.

BACKGROUND: Dilated cardiomyopathy (DCM) is a major cause of nonischemic heart failure and death in young adults. Next generation sequencing (NGS) has become part of the diagnostic workup in idiopathic and familial DCM. More than 50 DCM genes have been identified, revealing great molecular heterogeneity and variable diagnostic yield. Interpretation of variant pathogenicity is challenging particularly in underrepresented populations, as pathogenic variant databases include studies mainly from European/Caucasian populations. To date, no studies on genomic diagnosis of DCM have been conducted in Mexico. METHODS: We recruited 55 unrelated DCM patients, 22 familial (F-DCM), and 33 idiopathic (I-DCM), and performed site-directed NGS seeking causal mutations. Diagnostic yield was defined as the proportion of individuals with at least one pathogenic (P) or likely pathogenic (LP) variant in DCM genes. RESULTS: Overall diagnostic yield was 47.3%, and higher in F-DCM (63.6%) than in I-DCM (36.4%, p = 0.047). Overall, NGS disclosed 41 variants of clinical interest (61.0% novel), 27 were classified as P/LP and 14 of unknown clinical significance. Of P/LP variants, 10 were A-band region TTN truncating variants, five were found in DSP (18.5%), five in MYH7 (18.5%), two in LMNA (7.4%), and one in RBM20, ABCC9, FKTN, ACTA1, and TNNT2. NGS findings suggested autosomal recessive inheritance in three families, two with DSP loss of function mutations in affected individuals. The increasing number of mutation reports in DCM, increasing knowledge on the functional consequences of mutations, mutational hotspots and functional domains of DCM-related proteins, the recent refinement ACMG/ClinGen Guidelines, and co-segregation analysis in DCM families helped increase the diagnostic yield. CONCLUSION: This is the first NGS study performed in a group of Mexican DCM patients, contributing to understand the mutational spectrum and complexity of DCM molecular diagnosis.

Interannual variability of distribution, abundance and population dynamics of the smooth hammerhead Sphyrna zygaena (Linnaeus, 1758) in the central-southeast Pacific Ocean.

This study provides information on the population dynamics of the smooth hammerhead shark Sphyrna zygaena in the central-southeast Pacific Ocean. The samples were obtained from artisanal fisheries from 2008 to 2013 to analyse cohorts, growth, mortality, abundance and recruitment using methods based on length and relative age and an inference multi-model. According to the von Bertalanffy growth model, the results indicated that the species showed from three to seven cohorts annually and slow growth (Wi = 57.20%): L∞ = 292.86 cm, K = 0.141 per year and t0 = -2.26. Length of sexual maturity was 239.30 and 209.10 cm at first capture; the average natural mortality value was 0.231 per year, by fishing 0.051 per year with a total mortality of 0.26 1 per year and exploitation rate of 0.15. Interannual variability was recorded in biomass with an average of 7367.24 tonnes, as well as a spatial permanence pattern. The results suggest that the La Niña event biologically favours the population in the area. The information from this study is essential for better understanding the species population and serves as a basis for future actions of management and conservation of S. zygaena.

aeBlue Chromoprotein Color is Temperature Dependent.

BACKGROUND: Marine sessile organisms display a color palette that is the result of the expression of fluorescent and non-fluorescent proteins. Fluorescent proteins have uncovered transcriptional regulation, subcellular localization of proteins, and the fate of cells during development. Chromoproteins have received less attention until recent years as bioreporters. Here, we studied the properties of aeBlue, a a 25.91 kDa protein from the anemone Actinia equina. OBJECTIVE: To assess the properties of aeBlue chromoprotein under different physicochemical conditions. METHODS: In this article, during the purification of aeBlue we uncovered that it suffered a color shift when frozen. We studied the color shift by different temperature incubation and physicochemical conditions and light spectroscopy. To assess the possible structural changes in the protein, circular dichroism analysis, size exclusion chromatography and native PAGE was performed. RESULTS: We uncover that aeBlue chromoprotein, when expressed from a synthetic construct in Escherichia coli, showed a temperature dependent color shift. Protein purified at 4 °C by metal affinity chromatography exhibited a pinkish color and shifts back at higher temperatures to its intense blue color. Circular dichroism analysis revealed that the structure in the pink form of the protein has reduced secondary structure at 4 °C, but at 35 °C and higher, the structure shifts to a native conformation and Far UV- vis CD spectra revealed the shift in an aromatic residue of the chromophore. Also, the chromophore retains its properties in a wide range of conditions (pH, denaturants, reducing and oxidants agents). Quaternary structure is also maintained as a tetrameric conformation as shown by native gel and size exclusion chromatography. CONCLUSION: Our results suggest that the chromophore position in aeBlue is shifted from its native position rendering the pink color and the process to return it to its native blue conformation is temperature dependent.

Association of the whale shark Rhincodon typus with the cannonball jellyfish Stomolophus meleagris.

This study describes the first record of the whale shark Rhincodon typus association with the cannonball jellyfish Stomolophus meleagris in the Gulf of California, Mexico. Whale sharks were observed swimming and feeding among swarms of jellyfish, suggesting competition and predatory behaviour given the overlap in food preferences between both species. This finding is relevant because of the species-wide distribution and the importance of these interactions, which should be considered in conservation strategies of R. typus and management of cannonball jellyfish fisheries.

Newborn screening for six lysosomal storage disorders in a cohort of Mexican patients: Three-year findings from a screening program in a closed Mexican health system.

OBJECTIVE: To evaluate the results of a lysosomal newborn screening (NBS) program in a cohort of 20,018 Mexican patients over the course of 3years in a closed Mexican Health System (Petróleos Mexicanos [PEMEX] Health Services). STUDY DESIGN: Using dried blood spots (DBS), we performed a multiplex tandem mass spectrometry enzymatic assay for six lysosomal storage disorders (LSDs) including Pompe disease, Fabry disease, Gaucher disease, mucopolysaccharidosis type I (MPS-I), Niemann-Pick type A/B, and Krabbe disease. Screen-positive cases were confirmed using leukocyte enzymatic activity and DNA molecular analysis. RESULTS: From July 2012 to April 2016, 20,018 patients were screened; 20 patients were confirmed to have an LSD phenotype (99.9 in 100,000 newborns). Final distributions include 11 Pompe disease, five Fabry disease, two MPS-I, and two Niemann-Pick type A/B patients. We did not find any Gaucher or Krabbe patients. A final frequency of 1 in 1001 LSD newborn phenotypes was established. DISCUSSION: NBS is a major public health achievement that has decreased the morbidity and mortality of inborn errors of metabolism. The introduction of NBS for LSD presents new challenges. This is the first multiplex Latin-American study of six LSDs detected through NBS.

Diversidad taxonómica y funcional en la comunidad de peces de la pesca de arrastre de camarón en el norte del Golfo de California, México / Taxonomic and functional diversity of the bycatch fishes community of trawl fishing from Northern Gulf of California, Mexico

ResumenLa parte norte del Golfo de California es una zona mega diversa de alto endemismo con gran interés económico por las pesquerías multiespecíficas que se desarrollan, principalmente de camarón. Existe carencia de estudios recientes sobre ensamblajes de peces componentes de la fauna acompañante. Por lo que, durante las temporadas de pesca 2009-2010 y 2010-2011 se realizaron 14 viajes de pesca comercial a bordo de 13 barcos camaroneros, con un total de 119 lances, efectuados entre los 5 y 90 m de profundidad. Los 119 lances fueron analizados para evaluar la estructura de la comunidad de peces. Se utilizaron índices de diversidad taxonómica para detectar cambios taxonómicos en la comunidad siguiendo el índice de distinción taxonómica promedio Δ+ y el índice de variación taxonómica Δ* (TAXDEST del programa PRIMER v6). Para la conformación de grupos funcionales se consideró las similitudes de rasgos ecológicos y morfológicos entre las especies. Los resultados mostraron que los índices Δ+ y Δ* estuvieron dentro del promedio estimado y por dentro de los intervalos de confianza al 95 %, se encontraron diferencias significativas entre los índices. Los análisis mostraron una comunidad bien estructurada debido a la gran variedad de formas y funciones de las especies dentro de la comunidad. En la composición de grupos funcionales, el atributo ecológico que más contribuyó para conformación grupos, fue el gremio reproductivo. La estructura de la comunidad fue representada por niveles tróficos intermedios 3-3.9, preferencialmente carnívoros primarios y carnívoros secundarios, dentro de las categorías tróficas de ictiobentófagos y zoobentófagos, pertenecientes a especies demersales de fondos blandos y mayormente de cuerpo fusiforme.Se concluye que el NGC presentó alta redundancia funcional de acuerdo a los grupos funcionales estimados, por lo que se considera un ecosistema estable y de gran diversidad. Es recomendable dar seguimiento a este tipo de estudios utilizando información de esfuerzo pesquero y ambiental, debido a la gran importancia biológica y ecológica del área.

Abstract The Northern Gulf of California (NGC) is a mega diverse area of high endemism with major economic interest because of the multi-specific fisheries developed, mainly shrimp. There is a lack of recent studies on bycatch fish assemblages, so during the fishing seasons from 2009-2010 and 2010-2011, on board 13 shrimp boats, 14 commercial fishing trips were performed from 5 m - 90 m in depth with a total of 119 catches. The 119 catches were analyzed to assess fish community structure using taxonomic diversity indices to detect changes in the community following the taxonomic distinctness average Δ+ and the diversity index Δ* (TAXDEST of the PRIMER v6 program). To confirm the structure of functional groups, we considered similarities of ecologic and morphologic traits among species. The results showed that the indices Δ+ and Δ* were within the expected average and confidence intervals at 95%, finding significant differences between the indices. The analyses showed a well-structured community because of the great variety of forms and functions of the species within the community. In the community of the functional groups, reproduction was the ecological attribute that contributed the most to their structure. The community structure was represented by intermediate trophic levels (3-3.9), preferably primary and secondary carnivores within the trophic categories of predators of benthic ichthyo-fauna that belong to demersal species of soft bottoms and mostly fusiform body. To conclude, the NGC showed high functional redundancy according to the estimated functional groups, thus the ecosystem was considered stable and with great diversity. This type of studies should be followed using fishing and environmental effort due to the great biological and ecologic importance in the area.

[Taxonomic and functional diversity of the bycatch fishes community of trawl fishing from Northern Gulf of California, Mexico]. / Diversidad taxonómica y funcional en la comunidad de peces de la pesca de arrastre de camarón en el norte del Golfo de California, México.

The Northern Gulf of California (NGC) is a mega diverse area of high endemism with major economic interest because of the multi-specific fisheries developed, mainly shrimp. There is a lack of recent studies on bycatch fish assemblages, so during the fishing seasons from 2009-2010 and 2010-2011, on board 13 shrimp boats, 14 commercial fishing trips were performed from 5 m - 90 m in depth with a total of 119 catches. The 119 catches were analyzed to assess fish community structure using taxonomic diversity indices to detect changes in the community following the taxonomic distinctness average Δ+ and the diversity index Δ* (TAXDEST of the PRIMER v6 program). To confirm the structure of functional groups, we considered similarities of ecologic and morphologic traits among species. The results showed that the indices Δ+ and Δ* were within the expected average and confidence intervals at 95%, finding significant differences between the indices. The analyses showed a well-structured community because of the great variety of forms and functions of the species within the community. In the community of the functional groups, reproduction was the ecological attribute that contributed the most to their structure. The community structure was represented by intermediate trophic levels (3-3.9), preferably primary and secondary carnivores within the trophic categories of predators of benthic ichthyo-fauna that belong to demersal species of soft bottoms and mostly fusiform body. To conclude, the NGC showed high functional redundancy according to the estimated functional groups, thus the ecosystem was considered stable and with great diversity. This type of studies should be followed using fishing and environmental effort due to the great biological and ecologic importance in the area.

[Determination of stress in fish community obtained from shrimp trawl fishing in Northern Gulf of California]. / Estrés en la comunidad íctica en la pesca de arrastre del camarón en el norte del Golfo de California.

Bottom trawling has been considered a fishing activity that affects and modifies habitats, because of its impacts in species composition and abundance, and the alteration in the structure and function of the eco-system, that generates biodiversity loss. The Northern part of the Gulf of California has been considered a mega diverse zone with high endemism, and it is of growing interest by the international scientific community. In order to assess its potential changes in the fish community components of shrimp by-catch (FAC) in this area, a total of 119 trawls from 13 fishing boats were analyzed in Puerto Peñasco, based on 14 commercial fishing trips made within 9-90 m depth from 2010-2011. A random sample of 20 kg was obtained from each trawl, and was analyzed in the laboratory for species composition. In addition to the Index of Biological Value (IVB), Shannon diversity (H'), and Pielou evenness (J'), comparative abundance-biomass curves (ABC) were also estimated. Eucinostomus dowii showed the highest IVB = 480.25; Porichthys analis showed greater relative abundance; and Pomadasys panamensis showed greater frequency of occurrence. The mean monthly values in diversity H' = 3.05 (2.72 > H' < 3.25) and J' = 0.71 (0.66 < J' >0.81) showed a tendency to decrease as the fishing season progressed. The comparative abundance-biomass curves (ABC), and the value of statistical W showed moderate stress levels in March (W= -0.022) and September (W= -0.02) 2010, and January 2011 (W= -0.042). In conclusion, the Northern Gulf of California showed a well-structured community with a degree of moderate fishing stress.

Estrés en la comunidad íctica en la pesca de arrastre del camarón en el norte del Golfo de California / Determination of stress in fish community obtained from shrimp trawl fishing in Northern Gulf of California

La pesca de arrastre ha sido considerada como una actividad que impacta y modifica hábitats, provoca cambios en la composición y abundancias de las especies y altera la estructura y funcionamiento del ecosistema, generando finalmente una pérdida de la biodiversidad. La parte norte del Golfo de California ha sido considerada una zona mega diversa de alto endemismo y es motivo de interés creciente por la comunidad científica internacional. Con la finalidad de evaluar potenciales cambios en la comunidad de peces componentes de la fauna de acompañamiento del camarón (FAC), durante 2010-2011 se analizaron 119 arrastres de 13 embarcaciones camaroneras con base en Puerto Peñasco, a partir de 14 viajes de pesca comercial realizados a 9-90 m. Una muestra aleatoria de 20 kg fue obtenida de cada arrastre y analizada en el laboratorio para la composición de las especies. Adicional al Índice de Valor Biológico (IVB), diversidad de Shannon (H'), equitatividad de Pielou (J') fueron estimadas las curvas comparativas Abundancia-Biomasa (ABC). Eucinostomus dowii fue la mayor en IVB = 480.25, Porichthys analis la de mayor abundancia relativa y Pomadasys panamensis presentó la mayor frecuencia de ocurrencia. Los valores mensuales promedio en la diversidad H' = 3.05 (2.72 > H' < 3.25) y J' = 0.71 (0.66 < J' > 0.81) presentaron tendencia a decrecer conforme avanza la temporada de pesca. El comparativo curvas abundancia-biomasa (ABC) y el valor del estadístico W, evidenciaron a marzo (W = -0.022) y septiembre (W = -0.02) 2010 y enero 2011 (W = -0.042) con niveles de estrés moderado. En conclusión, la región norte del Golfo de California presentó una comunidad bien estructurada con grado de estrés moderado, aunque no explicado totalmente por la pesca.

Bottom trawling has been considered a fishing activity that affects and modifies habitats, because of its impacts in species composition and abundance, and the alteration in the structure and function of the ecosystem, that generates biodiversity loss. The Northern part of the Gulf of California has been considered a mega diverse zone with high endemism, and it is of growing interest by the international scientific community. In order to assess its potential changes in the fish community components of shrimp by-catch (FAC) in this area, a total of 119 trawls from 13 fishing boats were analyzed in Puerto Peñasco, based on 14 commercial fishing trips made within 9-90 m depth from 2010-2011. A random sample of 20 kg was obtained from each trawl, and was analyzed in the laboratory for species composition. In addition to the Index of Biological Value (IVB), Shannon diversity (H'),and Pielou evenness (J'), comparative abundance-biomass curves (ABC) were also estimated. Eucinostomus dowiishowed the highest IVB = 480.25; Porichthys analisshowed greater relative abundance; and Pomadasys panamensisshowed greater frequency of occurrence. The mean monthly values in diversity H'= 3.05 (2.72 > H'< 3.25) and J'= 0.71 (0.66 < J'>0.81) showed a tendency to decrease as the fishing season progressed. The comparative abundance-biomass curves (ABC), and the value of statistical Wshowed moderate stress levels in March (W = -0.022) and September (W = -0.02) 2010, and January 2011 (W = -0.042). In conclusion, the Northern Gulf of California showed a well-structured community with a degree of moderate fishing stress.

Guía de práctica clínica. Intervenciones de enfermería en el adulto mayor con fractura de cadera / Clinical practice guideline Nursing interventions for the older adult with hip fracture

Resumen:

Introducción: el crecimiento acelerado de la población envejecida va acompañado de un incremento de enfermedades crónicas y de individuos con mayor vulnerabilidad fisiológica. En México, las fracturas de cadera constituyen un problema importante de salud pública en personas mayores de 60 años. Están consideradas a nivel mundial como una de las causas de muertes accidentales en los adultos mayores y son de las lesiones secundarias incapacitantes más comunes que se atienden en unidades médicas. La presente guía pone a disposición del personal de enfermería las recomendaciones basadas en la mejor evidencia disponible a fin de estandarizar el cuidado de enfermería en la atención del adulto mayor con fractura de cadera, y así contribuir en la capacitación y la actualización del personal de enfermería para mejorar la calidad de la atención.

Desarrollo: a partir de preguntas clínicas, se estableció una secuencia de estrategias para la búsqueda de guías de práctica clínica e información relacionada con el tema. La metodología utilizada fue mixta. Los documentos se buscaron en inglés o español y no debían tener más de 10 años de publicación. Se utilizaron los centros compiladores de guías de práctica clínica y bases de datos tales como Cochrane Library Plus, AHRQ, SING, GIB, Fisterra y SEGG. Se aplicó el instrumento AGREE y las recomendaciones se complementaron con revisiones sistemáticas y narrativas, que se gradaron con la escala de Shekelle.

Conclusiones: con la implementación de esta guía, se espera que mejore la calidad en la atención del adulto mayor con fractura de cadera.

Abstract:

Introduction: Worldwide, the population of adults over 60 years of age has grown remarkably rapidly. The rapid growth of the aging population in Mexico is accompanied by an increase in chronic diseases and in persons with greater physiological vulnerability. Hip fractures are now a major public health problem in this country, accounting for 9 out of 10 fractures in people over the age of 60. Hip fracture is one of the leading causes of accidental death, and one of the most common disabling injuries in the elderly.

Development: The purpose of this clinical practice guideline is to standardize nursing care of the elderly with a hip fracture —based on the best available evidence—, and to assist in training and updating nursing service providers to improve the quality of care. Clinical questions were formulated and a sequence of search strategies for clinical practice guidelines and related information was established. It was used a mixed methodology.

The search was limited to papers not more than 10 years after publication in English or Spanish. Compilation centers of Clinical Practice Guidelines and databases such as Cochrane Library Plus, AHRQ, SING, GIB, Finisterre and SEGG were used. The AGREE instrument was used, and recommendations were supplemented by systematic reviews and narrative sorting using the Shekelle scale. Conclusions: It is expected that the implementation of this Nursing Clinical Practice Guide will improve the quality of care of elderly persons with hip fractures, and reduce variation in nursing interventions.

Fecundidad de la medusa Stomolophus meleagris (Rhizostomeae: Stomolophidae) en el Golfo de California / Stomolophus meleagris fecundity (Rhizostomeae: Stomolophidae) in the Gulf of California

The cannonball jellyfish Stomolophus meleagris is regarded as a fishery resource with high commercial value, but with scarce biological information. With the aim to generate preliminary information on reproductive aspects, the present study analyzes its fecundity, based on the estimated number of vitellogenic oocytes in the gonad; in addition, we evaluated its relationship with the jellyfish body length, diameter and wet weight; and we established the relationship of the gonadosomatic index (IGS) with the jellyfish diameter and length. For this, a total of 30 specimens were collected, measured and weighed in a monthly basis, in Las Guásimas lagoon from January to May 2006. In order to estimate the gonad volume, 60 mature females were analyzed and their gonads were extracted and stained with hematoxylin-eosin. Gonad images from histological preparations were analyzed and the number of vitellogenic and previtellogenic oocytes obtained. We used catch data from The Guásimas for population recruitment analysis, that was estimated with FISAT II. Among results, we found that fecundity increased with jellyfish length, diameter and total wet weight. The lower fecundity rates occured on February and the highest during May (11 873 071 and 37 528 197 millions of vitellogenic oocytes per gonad, respectively). The IGS increased with length and diameter of the specimens, at its maximum value of 3.7% was observed in May. A continuous production of previtellogenic oocytes were observed during the full collection period. The maximum recruitment was observed in July and November (37.50% and 28.01% respectively). The high fecundity observed in S. meleagris, suggests a high population reproductive potential that may support the possibility of an important fishery consolidation on this jellyfish.

La medusa Stomolophus meleagris es considerada un recurso pesquero de alto valor comercial. Debido a la relevancia de conocer aspectos de importancia biológica actualmente desconocidos, el presente trabajo analiza la fecundidad con base en la estimación del número de ovocitos vitelogénicos en la gónada; su relación con la longitud, diámetro y peso húmedo; y la relación del índice gonadosomático (IGS) con su diámetro y longitud. De enero a mayo 2006 se recolectaron 30 ejemplares mensuales que fueron medidos y pesados, de los cuales se analizaron 60 hembras maduras para calcular el volumen de sus gónadas. Se extrajeron las gónadas, se tiñeron con hematoxilina-eosina y se seleccionaron las hembras con madurez gonadal. Mediante la digitalización de imágenes se estimó el número de ovocitos vitelogénicos y previtelogénicos. Se emplearon datos de captura en Las Guásimas para el análisis de reclutamiento poblacional, estimado con FISAT II. La fecundidad se incrementó con la longitud, el diámetro y el peso húmedo total. La menor fecundidad se observó en febrero y la mayor en mayo (11 873 071 y 37 528 197 millones de ovocitos vitelogénico por gónada, respectivamente). El IGS se incrementó con la longitud y diámetro de los ejemplares, con su máximo en mayo de 3.7%. Se observó una producción continua de ovocitos previtelogénicos en todo el periodo de recolecta. El máximo reclutamiento se observó en julio y noviembre (37.50% y 28.01% respectivamente). La alta fecundidad encontrada en S. meleagris sugiere un alto potencial reproductivo para la población y sustenta la posibilidad de la consolidación de una importante pesquería de esta medusa.

Darkedge midshipman Porichthys analis (Batrachoidiformes: Batrachoididae), a common shrimp-bycatch fish from the Gulf of California

Shrimp fishery bycatch of the Gulf of California constitutes a wide variety of highly unknown fish, crustacean, and mollusk species with very low or null economic value, in contrast to those of commercial interest. However, there are no studies yet on the role of these low economic valued species have in the community structure and function, together with their possible effect on commercial populations. With the aim of contributing to the knowledge of Darkedge Midshipman fish Porichthys analis, the most common waste species in this fishery, we estimated some population characteristics. For this purpose, we obtained shrimp-bycatch fish during the 2004-2005 fishing season and performed some research surveys. A total of 1 725 Darkedge Midshipman were captured from 350 bycatch samples. Individual size ranged from 43-352mm SL. The weight to standard length relationship was determined as W=0.000092SL3.0509. Von Bertalanffy’s growth coefficient indicated a moderate growth rate (K=0.5) with an estimated asymptotic length ofL∞=352mm standard length, and a longevity of 6yr. Natural mortality was estimated as 0.97 and total mortality as 4.67. The recruitment pattern, as estimated by ELEFAN II, was extended over the year, peaking during spring and summer seasons. Sexual proportion of male:female was 1.65:1. Mature organisms appeared from August to March, and length at maturity was 157mm SL, which is larger than the mean size at capture 135mm SL. We concluded that the species is indirectly protected by its own bathymetric distribution and the off-shrimping season. This is the first study that considers population characteristics from this common but still unknown species.

A diferencia de las especies de interés comercial, la historia de vida de los peces no comerciales es casi desconocida a pesar de su potencial importancia en la estructura y función de la comunidad. Para contribuir al conocimiento de estas especies se estimaron algunas características poblacionales del chupalodo Porcihchty sanalis. La fauna de acompañamiento de la pesquería del camarón en el Golfo de California está constituida por especies poco conocidas y de escaso valor comercial. Las especies de la familia Batrachoididae son frecuentemente utilizadas como animales experimentales, pero poco se sabe de P. analis. De esta manera a partir de la fauna de acompañamiento se recolectaron 1 725 organismos y se determinó la relación talla-peso W=0.000092SL3.0509. Mediante ELEFAN I, se estimó un crecimiento moderado (K=0.5/año) con una longitud asintótica mayor que la observada reportada anteriormente (L∞=352mm SL) y una longevidad de 6 años. La mortalidad natural se estimó en M=0.97 la total en Z=4.67. El patrón de reclutamiento fue mayor durante primavera-verano. La proporción sexual M:F fue 1.65:1 y la talla media de primera madurez fue de 157mm SL mayor que la talla media de captura 135mm SL. Este es el primer reporte que considera las características poblacionales de esta especie común, pero poco conocida.

[Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico]. / Composición taxonómica y aspectos zoogeográficos de peces de profundidad (90-540m) del Golfo de California, México.

The Gulf of California has a high variety of ecosystems that allow different services and the fishery resources play a prominent role in its ecology, evolution and economics. Fish coastal species have been previously reported for most coastal areas, especially those species that are subject to fishing, however, little is known on the species from deep sea zones, due to sampling difficulties. We studied the deep sea fishes collected with trawl nets during three research surveys in the Gulf of California, Mexico in 2004-2005. We provide a systematic checklist and some notes on biogeographical aspects. For this, 74 fishing hauls were done, and a total of 9 898 fishes were captured, belonging to two classes, 15 orders, 35 families, 53 genera and 70 species. The best represented families in number of species were: Paralichthyidae (eight), Serranidae (six), and Scorpaenidae and Triglidae with five species each one. The typical families from deep waters were: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae and Cynoglossidae. Size range varied from 13cm for the Splinose searobin (Bellator xenisma) to 234cm in the Pacific Cutlassfish (Trichiurus nitens). The biogeographical affinity showed that species with affinity to the East Tropical Pacific (ETP) dominated, followed by species from San Diego-Panamic, San Diego-Panamic-Peruvian-Chilean and Oregonian-Cortes provinces, respectively. A biogeographic overlap was found in the fauna, which reflects the Gulf of California's geographical position, with distribution limits of species from temperate, tropical and warm-temperature transition affinities, divisions that characterize the Gulf of California. Taxonomic status of fish with a focus on composition, location, characterization and zoogeography are fundamental to any subject of biodiversity and fisheries management actions.

Composición taxonómica y aspectos zoogeográficos de peces de profundidad (90-540m) del Golfo de California, México / Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico

Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico. The Gulf of California has a high variety of ecosystems that allow different services and the fishery resources play a prominent role in its ecology, evolution and economics. Fish coastal species have been previously reported for most coastal areas, especially those species that are subject to fishing, however, little is known on the species from deep sea zones, due to sampling cifficulties. We studied the deep sea fishes collected with trawl nets during three research surveys in the Gulf of California, Mexico in 2004-2005. We provide a systematic checklist and some notes on biogeographical aspects. For this, 74 fishing hauls were done, and a total of 9 898 fishes were captured, belonging to two classes, 15 orders, 35 families, 53 genera and 70 species. The best represented families in number of species were: Paralichthyidae (eight), Serranidae (six), and Scorpaenidae and Triglidae with five species each one. The typical families from deep waters were: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae and Cynoglossidae. Size range varied from 13cm for the Splinose searobin (Bellator xenisma) to 234cm in the Pacific Cutlassfish (Trichiurus nitens). The biogeographical affinity showed that species with affinity to the East Tropical Pacific (ETP) dominated, followed by species from San Diego-Panamic, San Diego-Panamic-Peruvian-Chilean and Oregonian-Cortes provinces, respectively. A biogeographic overlap was found in the fauna, which reflects the Gulf of California’s geographical position, with distribution limits of species from temperate, tropical and warm-temperature transition affinities, divisions that characterize the Gulf of California. Taxonomic status of fish with a focus on composition, location, characterization and zoogeography are fundamental to any subject of biodiversity and fisheries management actions.

El Golfo de California tiene una alta variedad de ecosistemas que permiten obtener diferentes servicios y los peces juegan un papel prominente en la ecología, evolución y economía de este. De los peces, las especies costeras han sido reportadas previamente para la mayoría de las zonas litorales, especialmente aquellas especies que son sujetas a explotación pesquera, sin embargo, poco se conoce de las especies que habitan en zonas marinas profundas, debido a lo difícil de su muestreo. Se presenta el listado sistemático y la afinidad biogeográfica de los peces recolectados en tres cruceros de investigación en el Golfo de California con red de arrastre. Se efectuaron 74 lances exploratorios y se capturó un total de 9 898 peces, integrados por dos clases, 15 órdenes, 35 familias, 53 géneros y 70 especies. Las familias mejor representadas en número de especies son: Paralichthyidae (ocho especies), Serranidae (seis), Scorpaenidae y Triglidae (cinco cada una). Las familias típicas de aguas profundas son: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae y Cynoglossidae. El intervalo de tallas encontrado varió de 13cm en la vaca doble hocico (Bellator xenisma) a 234cm en el sable del Pacífico Trichurus nitens. La afinidad biogeográfica muestra que dominaron las especies de afinidad al Pacífico Oriental Tropical (POT), seguidos por las especies de las provincias de San Diego-Panámica; San Diego-Panámica-peruano-chilena y provincias Oregoniana-de Cortés respectivamente. Se encontró un traslape biogeográfico de la fauna, la cual es reflejo de la posición geográfica del Golfo de California en los límites de distribución de los elementos en donde se manifiestan especies de afinidades templadas, tropicales y de transición templado-cálido, divisiones que caracterizan al Golfo de California. Los estatus taxonómicos en peces con un enfoque de composición, ubicación, caracterización y zoogeografía son fundamentales ...