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Copyright of Revista U.D.C.A Actualidad & Divulgación Científica is the property of Universidad de Ciencias Aplicadas y Ambientales U.D.C.A and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

En Colombia, las ictiozoonosis causadas por helmintos son poco estudiadas y permanecen desatendidas desde el sector de la salud pública, representando una interacción por explorar en términos de biodiversidad y salud. Caquetia kraussi es un pez nativo de Colombia y Venezuela de importancia económica, debido a su alto consumo por parte de comunidades locales. Esta investigación registra la fauna de helmintos parásitos asociados a C. kraussi en un sistema de laguna costera en el Caribe colombiano. En febrero y diciembre de 2020 se examinaron 32 especímenes de C. kraussi, de los que se recolectaron 242 helmintos en los estadíos de metacercaria y adulto. Los parásitos incluyeron metacercarias de los tremátodos Clinostomum sp., Austrodiplostomum sp., dos morfoespecies de Posthodiplostomum spp. y adultos de Oigogonotylus andinus además de adultos del acantocéfalo (Eoacanthocephala) Neoechinorhynchus sp. Estos resultados indican que C. kraussii actúa como hospedador definitivo de O. andinus. y Neoechinorhynchus sp., y como hospedador intermediario de Clinostomum sp., Posthodiplostomum spp. y Austrodiplostomum sp. Se reporta por segunda vez una población de O. andinus en Colombia y la ocurrencia de una morfoespecie del género Neoechinorhynchus que podría ser un reporte nuevo para Colombia. Además del aporte al conocimiento de la diversidad de helmintos asociados a peces, los resultados de esta investigación podrían ser aprovechados para generar recomendaciones para el manejo y control de helmintiasis en sistemas piscícolas artificiales que se surten de afluentes naturales y favorecen el establecimiento de hospederos y parásitos.

El conocimiento acerca de la ictiofauna de los tramos altos del río Meta, uno de los principales afluentes del Orinoco, es aún poco conocida. En este trabajo se presenta el primer listado de peces registrados para el río Ocoa, a partir de 51 901 individuos muestreados en 15 localidades durante el ciclo hidrológico de 2014, incluidas zonas urbanas en el municipio de Villavicencio. Se obtuvieron registros de 88 especies, distribuidas en 21 familias y 5 órdenes, lo que corresponde al 12% de las especies de agua dulce reportadas para la Orinoquia colombiana. La cobertura de muestreo (SC) estimada para el río Ocoa fue del 99.9%, con una riqueza de especies observada que representa el 93.6% de la riqueza esperada. Entre las especies recolectadas, 13 están reportadas solo para Colombia, 43 tienen uso pesquero y cuatro especies son introducidas (Caquetaia kraussii, Oreochromis niloticus, Poecilia reticulata y Poecilia cf. caucana). Estas últimas dominan en sitios alterados con bajos niveles de oxígeno. Este estudio constituye la primera aproximación al conocimiento de la ictiofauna de una de las subcuencas de mayor importancia para el municipio de Villavicencio.

Estimates of temporal trends in species' occupancy are essential for conservation policy and planning, but limitations to the data and models often result in very high trend uncertainty. A critical source of uncertainty that degrades scientific credibility is that caused by disagreement among studies or models. Modelers are aware of this uncertainty but usually only partially estimate it and communicate it to decision makers. At the same time, there is growing awareness that full disclosure of uncertainty is critical for effective translation of science into policies and plans. But what are the most effective approaches to estimating uncertainty and communicating uncertainty to decision makers? We explored how alternative approaches to estimating and communicating uncertainty of species trends could affect decisions concerning conservation status of freshwater fishes. We used ensemble models to propagate trend uncertainty within and among models and communicated this uncertainty with categorical distributions of trend direction and magnitude. All approaches were designed to fit an established decision‐making system used to assign species conservation status by the New Zealand government. Our results showed how approaches that failed to fully disclose uncertainty, while simplifying the information presented, could hamper species conservation or lead to ineffective decisions. We recommend an approach that was recently used effectively to communicate trend uncertainty to a panel responsible for setting the conservation status of New Zealand's freshwater fishes. [ABSTRACT FROM AUTHOR]

Pimelodus grosskopfii and Pimelodus yuma, two species endemic to the Magdalena-Cauca basin in Colombia, overlap in the ranges of some of their diagnostic characters, which hampers their correct morphological identification. Aiming to help discriminate these species, this study conducted an integrative analysis using traditional and geometric morphometrics, phylogenetic analysis based on partial sequences of the mitochondrial cytochrome c oxidase subunit 1 gene (COI, cox1) and the identification of diagnostic Single Nucleotide Polymorphism markers (SNP). The species differ significantly in body geometry, allowing 100% discrimination, which was reinforced by a phylogenetic analysis that recovered well-supported monophyly of each species (posterior probability > 0.95). Additionally, the traditional morphometric results corroborated some previously reported diagnostic traits for both species and let us describe one non-overlapping ratio related to the adipose fin length. Three of five SNP markers had reciprocally exclusive alleles suitable for identifying each species. The morphometric and molecular methods conducted in this study constitute alternative tools for the correct discrimination of P. grosskopfii and P. yuma in the wild and in captive populations used for aquaculture. [ABSTRACT FROM AUTHOR]

Traditionally, the von Bertalanffy model has been used as the only standard in the study of fish growth, considering it a priori as the only model that fits the length-age data of the species; a consideration that generates uncertainties in the values of the growth parameters that are estimated, since it is known that other growth models could also fit the length-age data. In this sense, in the Middle Orinoco region, a study of Brachyplatystoma rousseauxii growth was previously done using the traditional von Bertalanffy model, and the results were subsequently used to evaluate the population; hence the objective of the present work was to validate the results of the previous work, fitting the same length-age data to the growth models of the U Richards family, and selecting the best fit using the Akaike Information Criterion (AIC). As demonstrated in the first paper, the traditional von Bertalanffy model fitted the back-calculated length-age data, but only 35;4 %; while the majority (64,6 %) fitted the U von Bertalanffy, U Logistic, and U Gompertz models, with no superiority of any of them in the fit. The growth parameters estimated from na average model were somewhat from those obtained in the previous work, and therefore necessary to re-evaluate the resource to know its level of exploitation in the Middle Orinoco. [ABSTRACT FROM AUTHOR]

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The family Characidae is the most diverse group of fishes in the Neotropics with challenging systematics. The three genera Carlana, Parastremma, and Rhoadsia, formerly considered the subfamily Rhoadsiinae, are now included in the subfamily Stethaprioninae. Previous phylogenetic analyses did not include all genera of Rhoadsiinae, specifically Parastremma. Here, we estimated the phylogenetic relationships and divergence times of the genera of Rhoadsiinae (the Rhoadsia clade) relative to the most representative genera of the Characidae. We used six molecular markers from the mitochondrial and nuclear genome to estimate the phylogeny and divergence times. We confirmed the monophyly of the Rhoadsia clade. Furthermore, we estimated that the Central American genus Carlana and the western Colombian genus Parastremma diverged approximately 13 Mya (95% HPD 8.36-18.11), consistent with the early-closure estimates of the Isthmus of Panama (~15 Mya). The genus Rhoadsia, endemic to Western Ecuador and Northern Peru, was estimated to originate at around 20 Mya (95% HPD 14.35-25.43), consistent with the Andean uplift (~20 Mya). [ABSTRACT FROM AUTHOR]

Dada la importancia de los peces de agua dulce en la dieta de los ecuatorianos, existe la imperiosa necesidad de conocer más acerca de la calidad de las carnes de las especies nativas de peces en el Ecuador; por ello se realizó el estudio comparativo de la composición nutricional, antioxidante y sensorial del campeche (Chaetostoma fischeri) y la chola (Saccodon wagneri), procedentes de diferentes ríos en La Maná, Ecuador, en la época de verano. El peso promedio de C. fischeri fue de 450,5 gramos (g) y de talla 151 centímetros (cm) y en S. wagneri de 420,5 g y 141 cm. Se utilizó un diseño completamente al azar, con tres repeticiones, donde las variables en estudio estaban dispuestas en forma bifactorial 3×2 (Factor A = Quindigua, Calope, San Pablo; Factor B = C. fischeri y S. wagneri). La valoración química en el C. fischeri tuvo el nivel más alto en humedad (79,27 %) y proteína (27,36 %), mientras la S. wagneri en materia seca (32,80 %), lípidos (8,74 %), ceniza (9,14 %) y en elementos no nitrogenados (25,11 %). En cuanto a la actividad antioxidante, mostraron una elevada actividad de superóxido dismutasa (SOD) en el C. fischeri (7,63 unidades·miligramos-1 –U·mg-1– proteína) en comparación con la S. wagneri (12,60 U·mg-1 proteína). Mediante Absorción atómica se determinó la cantidad de mercurio en el campeche (49 microgramos·kilogramos-1 –µg·kg-1–) y en la chola (48 µg.kg-1). En el presente estudio hubo interacción rio x especie con el mejor desempeño para C. fischeri en los ríos Quindigua y Calope en cuanto a la composición química, actividad antioxidante y análisis sensorial, con los mayores valores en proteína, bajos en lípidos, adecuados resultados en cuanto al olor, color, textura y aceptabilidad.

En este trabajo se presenta una lista actualizada de los registros de especies de peces de la cuenca del río Ucayali, Perú, provenientes de datos publicados y no publicados. Los resultados muestran que la cuenca del Ucayali presenta una ictiofauna rica y diversificada con el registro de 734 especies distribuidas en 15 órdenes, 49 familias y 292 géneros. La Ictiofauna está compuesta por peces miniatura (4%), peces pequeños (39%), medianos (41%), grandes (13%) y gigantes (3%). Los grupos dominantes son los Characiformes (312 especies, 43.0 %), Siluriformes (270 especies, 36.8%), Gymnotiformes (51 especies, 6.9%), y Cichliformes (50 especies, 6.8%). Parte de la ictiofauna es compartida con cuencas adyacentes como Marañón, y Amazonas peruano, principalmente en la región de confluencia, lo que contribuye a la notable diversidad de peces en la cuenca. Se observó una alta riqueza de especies con distribución restricta de los géneros Orestias, Astroblepus, Trichomycterus, Hemibrycon, entre otras especies, que ocurren en la región de cabeceras. Estimativos de riqueza de especies considerando su distribución por cada 100 m de altitud, indican que la cuenca del Ucayali esta subestimada, esperándose encontrar hasta 1125 especies. Los resultados aquí presentados son antecedentes que coadyuvaran a la toma de decisiones con fines de conservación y desarrollo sustentable en la región amazónica.

Globally, policies aiming for conservation of species, free‐flowing rivers, and promotion of hydroelectricity as renewable energy and as a means to decarbonize energy systems generate trade‐offs between protecting freshwater fauna and development of hydropower. Hydroelectric turbines put fish at risk of severe injury during passage. Therefore, comprehensive, reliable analyses of turbine‐induced fish mortality are pivotal to support an informed debate on the sustainability of hydropower (i.e., how much a society is willing to pay in terms of costs incurred on rivers and their biota). We compiled and examined a comprehensive, global data set of turbine fish‐mortality assessments involving >275,000 individual fish of 75 species to estimate mortality across turbine types and fish species. Average fish mortality from hydroelectric turbines was 22.3% (95% CI 17.5–26.7%) when accounting for common uncertainties related to empirical estimates (e.g., handling‐ or catch‐related effects). Mortality estimates were highly variable among and within different turbine types, study methods, and taxa. Technical configurations of hydroelectric turbines that successfully reduce fish mortality and fish‐protective hydropower operation as a global standard could balance the need for renewable energy with protection of fish biodiversity. [ABSTRACT FROM AUTHOR]

This review analyzes the most relevant information from 88 publications of which 41 are focused on the nutritional and functional quality of canaryseed, which is native to the Mediterranean region with a world production of approximately 257,600 tons in 2020. It contains a moderate contribution of protein, within which stands out some amino acid content rich in lysine, arginine and tryptophan, higher than other edible grains, it also has a high content of monounsaturated and polyunsaturated fats; in addition, it has been found to provide a high content of lipase type enzymes helping in the reduction of triglycerides in the blood when used as an ingredient in the diet of humans. More recent studies indicate that it is a very important source of sterols, which is why this seed has been used in popular culture to treat problems associated with increased cholesterol and some cardiovascular diseases, especially in people with obesity. However, in freshwater fish the use of this seed has not been potentiated to increase aspects such as added value and to propose new non-conventional ingredients for the aquaculture food industry, therefore, these aspects are the central part of this review. [ABSTRACT FROM AUTHOR]

Ecoregions and areas of endemism are central concepts in biogeography. Based on collection records and the Endemic Analyses implemented with NDM/VNDM method we analyzed fish areas of endemism in the junction of three freshwater ecoregions related to the Rio de la Plata estuary (Lower Parana, Lower Uruguay, Laguna dos Patos) in Southern Neotropical region. Using two grid cell sizes, results obtained showed the same general patterns. Areas of endemism recovered were mainly associated either to Lower Uruguay or to Laguna dos Patos. In both ecoregions nested areas of endemism were identified within larger patterns of endemism. Noteworthy, one area recovered occurred across Lower Uruguay and Laguna dos Patos limits. Our results also suggest a revision of the Lower Uruguay and Lower Parana ecoregion limits, and highlight the relevance of the Rio de la Plata estuary as a barrier and corridor for freshwater fishes in the area. [ABSTRACT FROM AUTHOR]

Conocer las especies que habitan en determinadas áreas, es el punto de partida en estrategias de conservación. En este sentido, el objetivo del trabajo fue identificar las especies de peces que habitan en el área de conservación Parque Kasama y las propuestas de áreas de conservación en la provincia de Santo Domingo de los Tsáchilas. Como resultado se identificaron 26 especies de peces, pertenecientes a 22 géneros, 13 familias y 5 órdenes. El 45 % de las especies se encuentra en estado de Preocupación Menor, el 31 % poseen Datos Insuficientes, el 8 % están Casi Amenazados y el 4 % son Vulnerables. Al considerar que la mayor diversidad de peces de agua dulce se encuentra en ríos con vegetación marginal, las propuestas de áreas de conservación garantizarán la manutención de especies ictiológicas en la Provincia de Santo Domingo de los Tsáchilas.

Introducción: El conocimiento sobre la composición taxonómica de la fauna de peces de agua dulce de Costa Rica ha cambiado sustancialmente en las últimas dos décadas. No solamente por la adición de nuevas especies y táxones supra-específicos, sino también por reordenamientos y cambios taxonómicos en los diferentes niveles jerárquicos. Las claves taxonómicas disponibles se publicaron hace más de 20 años y están desactualizadas. Objetivo: Brindar información actualizada, en lenguaje sencillo, para la identificación de todas las familias costarricenses de peces continentales e insulares. Métodos: Utilizamos literatura, colecciones de museos y especímenes recolectados recientemente para actualizar una lista del 2013. Resultados: La clave clave dicotómica ilustrada, que cubre 53 familias, se basa en características externas relativamente fáciles de identificar. También incluimos información sobre la composición de especies, distribución general y uso del hábitat. Conclusión: Esta clave permite la identificación de 274 especies de peces costarricenses a nivel de familia, como base para su identificación a categorías más bajas.

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Colombiana de Ciencia Animal - RECIA is the property of Revista Colombiana de Ciencia Animal - RECIA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Neotropical catfish species Ageneiosus pardalis, Pimelodus grosskopfii, and Sorubim cuspicaudus are important fishery resources in Colombia that show historical declines in their capture. This study used next-generation sequencing with 454 FLX technology (Roche Applied Science) and bioinformatics analysis to develop between 18 and 24 microsatellite loci for these species. The novel microsatellite loci showed high values of polymorphic information content -PIC (A. pardalis: 0.601-0.903, P. grosskopfii: 0.748-0.946 and S. cuspicaudus: 0.383-0.876), and the average number of alleles/locus ranged from 7-15 for A. pardalis, 9-30 for P. grosskopfii and 5-14 for S. cuspicaudus. The average observed and expected heterozygosities were respectively, 0.757 ± 0.035 and 0.834 ± 0.015 for A. pardalis; 0.596 ± 0.040 and 0.881 ± 0.009 for P. grosskopfii; and 0.747 ± 0.031 and 0.757 ± 0.025 for S. cuspicaudus. For future studies, these loci can be useful to estimate the genetic diversity and population structure in these three Neotropical catfishes. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Ciencia Animal - RECIA is the property of Revista Colombiana de Ciencia Animal - RECIA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introducción: Brycon henni es un pez nativo de los Andes entre otras localidades, se encuentra en el cauce del río Porce y sus quebradas tributarias en Antioquia, Colombia. Es además una especie de importancia comercial. Los estudios de evaluación gonadal de los peces permiten ver cómo se encuentran las poblaciones en su ambiente natural y cómo es la interacción con el medio acuático modificado. Objetivo: asociar los parámetros de talla y peso con el índice de madurez gonadal de Sabaleta (Brycon henni), con el objetivo de identificar el estado reproductivo en quebradas afluentes del río Porce. Metodología: en diez puntos de muestreo en quebradas afluentes al embalse Porce II y III, se capturaron 35 individuos a conveniencia utilizando atarraya. Se registró el peso total (g), longitud total estándar (LST) (cm), y el sexo. Luego se extrajeron y pesaron las gónadas (g). Se calculó el índice gonadosomático (IGS = [PG/PT] × 100), y el factor de condición (FC = [PT/LT ^3] × 100). Las gónadas se clasificaron de acuerdo la propuesta de Vazzoler, y para determinar microscópicamente el estado de madurez gonadal se realizó análisis histológico, se conservaron las gónadas en formol bufferado al 10 %. Resultados: las hembras (n = 8) presentaron una LST de 18,40 cm ± 5,07 cm y los machos (n = 27) 15,37 cm ± 3,74 cm. El peso fue 104,67g ± 62,65 g y 69,36 g ± 36,02 g para hembras y machos respectivamente. Los estadios de madurez en las hembras fueron 75 % A (inmaduro), 12,50 % B (en maduración) y 12,50 % D (desovado), para los machos, 3,70 % A, 22,22 % B y 74,07 % C (maduro). El índice gonadosomático (IGS) mostró valores de 0,41 ± 0,21 en hembras, y 2,96 ± 2,08 en los machos. El factor de condición (K) en las hembras fue de 1,72 ± 0,57 y en machos 1,91 ± 0,52. Conclusión: estos datos nos permiten conocer la variación de la actividad reproductiva de la especie en las microcuencas. Estudios previos reportan un índice gonadosomático en las hembras del género Brycon sp. de 0,47 ± 1,17 lo cual es similar a lo reportado en nuestra investigación, y para machos presentaron un índice de 0,07 ± 0,09, esto es menor al índice gonadosomático encontrado en este estudio posiblemente porque la mayoría de los machos encontrados se encontraban en estadio C de maduración. [ABSTRACT FROM AUTHOR]

La ictiofauna de la cuenca del río Magdalena, la mejor muestreada de Colombia, todavía presenta información escasa para algunas subcuencas. Tal es el caso de las subcuencas que drenan el nororiente colombiano, donde se están descubriendo nuevas especies y haciendo los primeros inventarios de muchos cuerpos de agua. En este artículo se describen los datos de la principal colección de peces del nororiente colombiano, la Colección Ictiológica de la Universidad Industrial de Santander, en Bucaramanga. Los primeros registros de la colección datan de diciembre de 2002 y a la fecha las colectas continúan activas. La mayoría de los ejemplares han sido recolectados en el sistema de la cuenca del Magdalena y en el departamento de Santander. También incluye ejemplares recolectados en los departamentos de Arauca, Atlántico, Bolívar, La Guajira, Meta, Norte de Santander y Valle del Cauca. La mayoría de los especímenes se fijaron en formol y preservaron en alcohol al 70 %. Actualmente la colección cuenta con 1665 registros, pertenecientes a 9 órdenes, 33 familias, 74 géneros y 100 especies. Los órdenes mejor representados son Characiformes (38,4 % de los registros), Perciformes (31,4 %) y Siluriformes (18,6 %). Entre los especímenes se cuenta con los holotipos de Astyanacinus yariguies y Gephyrocharax torresi y con paratipos de estas dos especies y de Trichomycterus uisae.

Se determinó la edad de Piaractus brachypomus descomponiendo la distribución de frecuencias de talla en cohortes que representaron edades, utilizando el método de Battacharya; mientras que el estudio del crecimiento se hizo por la inferencia de múltiples modelos, usando el criterio de la información de Akaike (AIC) para seleccionar el de mejor ajuste. Los modelos propuestos fueron las versiones unificadas del modelo de Richards (U-Richards), von Bertalanffy (U-von Bertalanffy), Logístico (U-Logístico) y Gompertz (U-Gompertz). La edad estuvo comprendida entre uno y tres años (a) de edad, con los peces de un a midiendo 13,0±1,9 centímetro (cm) de longitud total, los de dos a 25,2±3,0 cm de LT, y los de tres a 36,3±2,8 cm de LT. Desde el punto de vista estadístico, forma de la curva, AIC y biológico, el modelo de mejor ajuste fue el U-Gompertz, el cual produjo una curva sigmoidea determinada por una longitud asintótica de L= 71,9 cm de LT, una tasa de crecimiento relativo K = 0,148 a ∞ , un punto de inflexión en la curva Ti-1= 2,02 a y un punto inicial de la curva W= 8 cm de LT. P. brachypomus presentó un crecimiento relativamente lento que la hace vulnerable a la explotación pesquera, y por lo tanto, debe ser adecuadamente administrada.

A new species of whiptail armored catfish belonging to the genus Pseudohemiodon is described. The new species inhabits aquatic systems of the Orinoco River basin, mostly in the Llanos region of Colombia and Venezuela. Previously, it had identified as P. laticeps erroneously. The genus Pseudohemiodon includes seven known species inhabit Amazon and Paraná-Paraguay-Uruguay rivers basins. The new species is distinguished from congeners by the combination of the following characters: abdomen totally covered; area in front of gill opening without plates, ventrally; dorsal body color pattern without transversal dark bands, mostly in the caudal peduncle; head with straight sides; head and caudal peduncle narrower. [ABSTRACT FROM AUTHOR]

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ABSTRACT We investigated spatial and seasonal variation of fish assemblages of Caño Maraca, a creek in Venezuela’s Western Llanos, a region with strong wet-dry seasonality. Fishes were surveyed over a 19-year period at three sites along the longitudinal gradient: a headwater site with a narrow channel, a middle site with shallow channels traversing a seasonal wetland, and a lower site where the channel has higher banks. Assemblage composition and presence of species with juveniles and various life history strategies were compared during wet and dry seasons. Overall, fish species richness was lowest at the headwater site and highest at the downstream site. During the wet season, however, species richness is greatest at the middle site, a pattern associated with migration into the site for reproduction and use of the wetland as a nursery. During the dry season, species richness is greater at the downstream site where habitat quality is sufficient to provide suitable habitat for many species. Fish movements and population dynamics in Caño Maraca respond to seasonal environmental changes, and the fish metacommunity appears influenced by species sorting (habitat selection), mass effects (source-sink dynamics), patch dynamics (interspecific differences in colonization and species interaction) as well as random factors (dry-season strandings).

ABSTRACT Characiformes is an order of freshwater fishes that includes many commercially important and emblematic species from South America and Africa, such as the popular piranhas, hatchetfishes, African tiger fishes and tetras. The order is split into two suborders with a total of 24 families, 282 genera and ca. 2,100 species. Here, we present an expanded phylogeny of characiform fishes, including data for 520 species and three genes (12S, 16S and RAG1), and the recently described family Tarumaniidae, which has not been examined by previous molecular analysis. Although our genetic coverage is limited to three gene fragments, the tree inferred based on maximum likelihood and Bayesian inference supports the monophyly of all characiform families and is largely congruent with results from recent studies that sampled less taxa but more genes. Also in agreement with a morphological hypothesis, our results strongly support the sister-group relationships between the family Tarumaniidae and Erythrinidae. Based on our results and that of the other molecular analyses, we propose a revised circumscription of the superfamily Erythrinoidea to include the families Tarumaniidae and Erythrinidae only.

La laguna Hule es un cráter de origen volcánico que se ha inundado con el tiempo, dando como resultado una gran masa de agua, sin estudios previos sobre su comunidad de peces. Muestreamos durante cinco meses la laguna y una quebrada (Pata de Gallo) con redes, gancho y línea. Los especímenes capturados se identificaron in situ al nivel taxonómico posible más bajo. La laguna tenía especies que normalmente se encuentran cerca de la vegetación acuática: Amatitlania siquia, Amphilophus alfari, Astyanax aeneus, Cynodonichthys sp., Parachromis dovii, Phallichthys amates y Poecilia gillii (dominante: A. aeneus, P. gillii y P. amates). La quebrada estaba dominada por Brachyrhaphis olomina pero también tenía Rhamdia laticauda. Los índices de baja diversidad (1,48 en la laguna y 0,26 en la quebrada) son característicos de los ecosistemas lacustres. Las hembras fueron, como se esperaba, más grandes y abundantes en P. amates y B. olomina; mientras que en P. gilli, algunos machos eran más grandes. El área se ve afectada por la contaminación, la introducción de especies invasoras, la pesca incontrolada y el uso de equipo destructivo de pesca. Proponemos la demarcación del estado de protección del sitio y la organización de un grupo comunitario para proteger a esta comunidad de peces.

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Characiformes is an order of freshwater fishes that includes many commercially important and emblematic species from South America and Africa, such as the popular piranhas, hatchetfishes, African tiger fishes and tetras. The order is split into two suborders with a total of 24 families, 282 genera and ca. 2,100 species. Here, we present an expanded phylogeny of characiform fishes, including data for 520 species and three genes (12S, 16S and RAG1), and the recently described family Tarumaniidae, which has not been examined by previous molecular analysis. Although our genetic coverage is limited to three gene fragments, the tree inferred based on maximum likelihood and Bayesian inference supports the monophyly of all characiform families and is largely congruent with results from recent studies that sampled less taxa but more genes. Also in agreement with a morphological hypothesis, our results strongly support the sister-group relationships between the family Tarumaniidae and Erythrinidae. Based on our results and that of the other molecular analyses, we propose a revised circumscription of the superfamily Erythrinoidea to include the families Tarumaniidae and Erythrinidae only. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Between May 2004 and May 2005, we sampled fish in 19 sites, grouped in four elevations, ranging from the river mouth to 650 m.a.s.l. in the Río Pacuare, Caribbean versant of Costa Rica. Changes in the distribution and composition of the fish fauna, as well as patterns of alpha and beta diversity along an elevational gradient were assessed. Additional analyses of habitat preferences, trophic guilds, functional groups and general ecology for the most abundant species are included. All fish captured were classified into 22 families, 43 genera and 53 species. The most abundant family was Characidae, followed by Gobiidae, Mugilidae, Poeciliidae and Heptateridae, which together comprise 87.9% of all sampled individuals. Elevation shows an inverse effect on species diversity, we observed a monotonic decrease in species richness with increasing elevation (p < 0.05), as reported in other tropical rivers. According to our results, in the Río Pacuare the total fish fauna diversity is found within the first 500 m.a.s.l. Species turnover increases with elevation, while nestedness decreases. Turnover was dominated by the loss of species rather than gain; the higher species loss was registered between the river mouth and the lower river reach (< 100 m.a.s.l.). Seven species can be classified as typical or core species (Astyanax aeneus, Sicydium altum, Agonostomus monticola, Poecilia gillii, Brycon costaricensis, Rhamdia laticauda and Joturus pichardi) along the elevation gradient. The habitat availability and the integration of ecomorphological, feeding and reproductive traits help to explain better the elevation distribution of the complete set of species observed. Although it is possible to identify groups of species characteristic of each reach of river, this does not mean that they are isolated from each other. Natural drift and movement along the river of some species during their life cycle, especially S. altum, A. monticola and J. pichardi, are key processes linking the whole watershed. The present study constitutes a first step in documenting and understanding the distribution and composition of fish assemblages in a watershed that is relatively intact and well-conserved in the Caribbean versant of Costa Rica. [ABSTRACT FROM AUTHOR]

The Serial Discontinuity Concept affirms that the formation of reservoirs in cascade within rivers generates changes in the structure of the aquatic biota that accumulate along the basin. In the Porce River (Magdalena- Cauca River Basin, Colombia) two reservoirs were formed in cascade, Porce II and Porce III. To know the response of the fish assemblage in the sector of the river that was dammed, we collected samples during four periods of abundant rains and four of lesser rains from 2011 to 2013 from sites inside both reservoirs selected according to position on the longitudinal axis (tail, transition and dam). To eliminate the effect of depth, at every site, we took samples from two depths, surface and bottom. 15 species were captured; 12 in Porce II and 10 in Porce III. Differences in the composition and structure of the species of fish were found to vary depending on the location along the river flow (from tail to dam), and also by the water depth (surface to river bottom). In Porce II reservoir, the richness and the abundance of fish diminished in direction tail to dam and the abundance decreased from surface to bottom. In Porce III though the species richness presented the same trend along the longitudinal axis, the abundance was greater on the bottom that at the surface. The characteristics of the assemblage were not associated with the rainfall periods in either reservoir. One concludes that the composition and structure of the assemblage are defined by the morphologic characteristics of the reservoir, as well as the age and time of hydraulic retention. [ABSTRACT FROM AUTHOR]

The ichthyofauna of the Río Acahuapa was analyzed sampling 17 sites that included the basin main channel and its tributaries. Fish were collected using dip-nets, seine-nets and electrofishing. Fish standard length and species abundance were recorded. Species origin and salinity tolerance criteria were used to classify fish species. Water physicochemical variables, habitat structure and sampling sites elevation were recorded. A total of 33 fish species were registered, 12.1% are primary, 45.5% are secondary and 42.4% are of marine derivation. Fish species richness declined with increase of elevation (R²=0.55, p=0.0006). Two assemblages of fishes were identified: the first one associated to sites of low elevations (19-184 masl), composed mainly of secondary and marine-estuarine fish species related with high temperature, water velocity, river width, dissolved oxygen and low sand and silt substrate cover; the second one associated to sites of middle and higher elevations (185-519 masl), composed by primary and secondary freshwater fishes related with high pH, logs and rocks substrate cover. In summary, elevation and environmental variables contributed to the composition and distribution of fish in the Río Acahuapa. [ABSTRACT FROM AUTHOR]

In fishes, gonad morphology is an important parameter to understand the reproductive biology, phylogenetic relationships and systematic studies. The main objective of this study was to make a comparative analysis of the morphology of mature ovary and testis in six fish species of the family Anostomidae. A total of 212 specimens, presenting maturing gonads, were captured from the São Francisco River, Três Marias Reservoir area, in Southeastern Brazil, between August 2008 and December 2010. The six analyzed species had mature ovaries and showed a grayish color. In vitellogenic oocytes (VO), cortical alveoli (CA) were composed by small vesicles in all Leporinus species, but in Leporellus vittatus and Schizodon knerii the CA were large vesicles. However, the CA of all species showed similar histochemical content. The pellucid zone consists of two layers to all species, but it was thicker in S. knerii (11.5 ± 1.8 μm) than in L. vittatus (9.0 ± 0.8 μm) and Leporinus species (3.5 ± 0.6 - 8.7 ± 0.9 μm). Follicular cells of the VO were respectively cubic and prismatic in animal and vegetative poles of S. knerii (22.3 ± 3.2 and 61.1 ± 9.6 μm), and squamous in the other species (1.3 ± 0.3 - 1.6 ± 0.3 μm). Females of S. knerii and males of L. vittatus showed lower values of gonadosomatic index (GSI) than the other assessed species. All evaluated species presented testicular morphology similar to most neotropical Characiformes, with unrestricted spermatogonial testis and anastomosing tubular organization of seminiferous tubules. Phenotypical differences in the vitellogenic oocyte of Anostomidae fishes, confirmed the taxonomic position of S. knerii as different genus in relation to Leporinus and L. vittatus. Despite being placed in different genera, the characteristics of the vitellogenic oocytes of L. vittatus were similar to those found in the studied Leporinus. [ABSTRACT FROM AUTHOR]

This study investigated the parasitic fauna of Cichlasoma bimaculatum of a tributary from the Amazon River system, northern Brazil. The prevalence of infection was 94.6 % and, in total, 428 267 parasites, such as Ichthyophthirius multifiliis, Piscinoodinium pillulare (Protozoa), Gussevia arilla (Monogenoidea), Posthodiplostomum sp. (Digenea) and Procamallanus (Spirocamallanus) inopinatus (Nematoda) were collected. However, the dominance was mainly of I. multifiliis, while P. (S.) inopinatus was the parasite species with the lower levels of prevalence and abundance of infection. These parasite species showed an aggregated dispersion pattern. The parasitic fauna was characterized by the presence of few species of parasites with high prevalence and abundance, specifically ectoparasites, and a low number of endoparasites. The observed pattern is explained by the mode of life of the host and it is suggested that C. bimaculatum occupies a low trophic level at the food web. [ABSTRACT FROM AUTHOR]

The ichthyofauna of the Magdalena River Basin is the best sampled of Colombia and yet, there is scant information about the fish of some of its drainages. That is the case for the drainages of Colombia's North- East, where new species are being found during the first inventories of many freshwater sites. In this paper, we describe the database of the main freshwater fish collection of North-Eastern Colombia, the Ichthyological Collection of the Universidad Industrial de Santander in Bucaramanga. The collection started in December of 2002 and still active. Most of the specimens were collected in the Magdalena river basin system in the department of Santander. There are also specimens collected from the departments of Arauca, Atlántico, Bolívar, La Guajira, Meta, Norte de Santander and Valle del Cauca. Most of the specimens were fixed in formalin and preserved in 70% alcohol. There are currently 1665 records, corresponding to 9 orders, 33 families, 74 genera and 100 species. The most frequent orders were Characiformes (38.4% of the records), Perciformes (31.4%), and Siluriformes (18.6%). Among the specimens in collection are the holotype and paratypes of Astyanacinus yariguies and Gephyrocharax torresi and paratypes of Trichomycterus uisae. [ABSTRACT FROM AUTHOR]

Nowadays, the successful management of small scale fisheries requires the use of biometric data collected in the field, in order to transform them into suitable indicators. The present study describes the lengthweight relationships for 36 freshwater fish species from two tropical reservoirs Ayame I and Buyo, in Côte d’Ivoire. The main objective of the study was to provide a length weight key for a wide range of freshwater fish species from these tropical reservoirs exploited by the inland fisheries. The samplings were carried out at Buyo from July 1997 to August 1998, and from August 2004 to July 2005 in Ayame I. Fish specimens were collected from catches of artisanal fisheries using gill-nets, cast-nets, beach seines and bamboo traps. After landings, samples were identified, total weight for each specimen was recorded to the nearest gram and standard length was measured to the nearest millimetre. A total of 12 724 individuals belonging to 15 families and 24 genera were obtained in this study. The results indicated that the family with the highest number of species was Cichlidae with eight species. Six families were recorded with only one species per family. The value of the exponent b in the length weight relationships (W=aLb) ranged from 2.173 for Marcusenius furcidens to 3.472 for Polypterus endlicheri and the median of b was 2.756. The modal value of the exponent b equal to 2.70 indicates that most of the fish species in Ayame I and Buyo Reservoirs have negative allometric growth. The length weight parameters of the three species, Lates niloticus, Synodontis koensis and S. punctifer are described for the first time in these regions. The present length-weight key for 36 freshwater fish species could be used as a valuable tool for fishery managers, in order to improve the inland fisheries statistics largely based on hydropower reservoirs in Côte d’Ivoire.Hoy en día, el manejo exitoso de pesquerías a pequeña escala requiere el uso de datos biométricos recolectados en campo, y así poder transformarlos en indicadores apli- cables. El presente estudio describe la relación longitud-peso para 36 especies de peces de agua dulce encontrados en dos embalses hidroeléctricos tropicales en Ayame I y Buyo, en Costa de Marfil. El principal objetivo del estudio es proveer una clave de longitud-peso para una amplia variedad de peces de agua dulce provenientes de estos dos embalses, los cuales son explotados por pesquerías locales. El muestreo fue llevado a cabo en Buyo durante los meses de Julio 1997 a Agosto 1998, y en Ayame I de Agosto 2004 a Julio 2005. Los especímenes fueron tomados de trampas colocadas por pesqueros artesanales, utilizando redes de enmalle, atarraya, red de cerco y trampas de bambú. Los especímenes fueron identificados, pesados hasta el gramo más cercano y la longitud fue medida hasta el milímetro más cercano. Un total de 12 724 individuos pertenecientes a 15 familias y 24 géneros fueron obtenidos en este estudio. Los resultados muestran que la familia con más número de especies fue Cichlidae con 8 especies. En seis familias se obtuvo únicamente una especie. El valor del exponente b en la relación longitud-peso (w=al b) estuvo dentro del rango de 2.173 para Marcusenius furcidens, de 3.472 en Polypterus endlicheri, y la media de b fue 2.756. El valor modal del exponente b igual a 2.70 indica que la mayoría de especies de peces en las reservas Ayame I y Buyo tienen crecimiento alométrico negativo. Los parámetros longitud- peso de tres especies, Lates niloticus, Synodontis koensis and S. punctifer son descritos por primera vez en estas localidades. La clave longitud-peso presentada para 36 especies de peces puede ser utilizada como una herramien- ta valiosa para administradores pesqueros, y así mejorar ampliamente las estadísticas de las pesquerías basadas en embalses hidroeléctricos en Costa de Marfil.

Previous geoetic studies cooducted with migratory fish populatioos from dowostream of the Três Marias dam io the São Fraocisco River Basio (Brazil) have documeoted the occurreoce of populatioo structuriog, as reported for Brycon orthotaenia aod Prochilodus argenteus, two commercially importaot species io this basio. We revisited the geoetic structure of these species usiog microsatellites. B. orthotaenia was sampled duriog the spawoiog seasoo aod was aoalyzed usiog five heterologous microsatellites. P. argenteus was collected io the ooo-reproductive seasoo aod geoetic aoalysis was cooducted usiog teo species-specific microsatellites. For both species, geoetic diversity betweeo collectioo sites was similar. Coosideriog B. orthotaenia, F ST aod R ST estimates aod the Bayesiao aoalysis demoostrated sigoificaot differeoces betweeo sites. Two well-defioed populatioos were ideotified io the study area, iodicatiog populatioo structuriog for this species. No sigoificaot differeoces were fouod for P. argenteus. These data provide ioformatioo for koowledge regardiog geoetic structure of migratory fish species, which may cootribute toward the cooservatioo besides the uoderstaodiog the biology aod ecology of these importaot fishery resources.Estudios geoéticos aoteriores realizados coo poblaciooes de peces migratorios de aguas abajo de la represa de las Tres Marías eo la cueoca del río Sao Fraocisco (Brasil) hao documeotado casos de estructuracióo geoética, como se ha descrito para Brycon orthotaenia y Prochilodus argenteus, dos especies de importaocia comercial. Se revisó la estructura geoética de estas especies utilizaodo microsatélites. Se obtuvieroo muestras de B. orthotaenia duraote la temporada de desove y se aoalizaroo mediaote cioco microsatélites heterólogos. Muestras de P. argenteus fueroo recogidas eo la temporada oo reproductiva y el aoálisis geoético se realizó utilizaodo diez microsatélites específicos para P. argenteus. Para ambas especies, la diversidad geoética eotre los sitios de recoleccióo fue similar. Coosideraodo a B. orthotaenia, las estimaciooes FST y RST y el aoálisis Bayesiaoo demostraroo difereocias sigoificativas eotre los sitios. Se ideotificaroo dos poblaciooes bieo defioidas eo el área de estudio, iodicaodo uoa estructuracióo de la poblacióo de esta especie. No se eocootraroo difereocias sigoificativas para P. argenteus. Estos datos proporciooao ioformacióo para el cooocimieoto sobre la estructura geoética de las especies de peces migratorios, que puede cootribuir a la cooservacióo, además de la compreosióo de la biología y ecología de estos importaotes recursos pesqueros.

A freshwater fish Roeboides loftini n.sp. is described from the Río Coclé del Norte drainage of the Atlantic versant of Panamá. The new species differs from other species of the Roeboides guatemalensis-group by the number of perforated scales on the lateral line (83-100), body depth (31.8-36.1%), predorsal distance (49.1-51.9%) and the shape of the humeral spot. Rev. Biol. Trop. 59 (4): 1663-1667. Epub 2011 December 01

Based on a compilation of data on massive fish deaths occurred in southern South America during the Twentieth Century, we assessed the importance of climatic variables on these phenomena. We found a strong relationship (R² =0.68) between these massive fish deaths and the mean monthly air temperature. Along the annual temperature range there is a central range (14.6° C to 20.0° C), where the probabilities that a fish community suffers massive deaths is very low. Its central point (17.3° C) is very close to the mean annual value (17.2° C) of air temperature variation. We considered this agreement as corroboration at community level of Pianka’s theory on physiological optima. This relationship allows to monitoring the influence of climate changes, because the environmental variation and the zones of mortality and no mortality will change with predicted changes of the mean monthly values of air temperature.Basado en la recopilación de datos de mortandades masivas de peces ocurridas en el sur de Sud América durante el Siglo XX, se evaluó la importancia de las variables climáticas en estos fenómenos. Se encontró una fuerte relación (R² =0,68) con la temperatura media mensual del aire. A lo largo del rango de temperaturas anuales hay un rango central (14,6° C a 20,0° C) donde las probabilidades que una comunidad de peces sufra mortandades masivas son muy bajas. Su punto central (17,3° C) es muy cercano al valor medio anual (17,2° C) de la variación de temperatura del aire. Se considera esto como una corroboración a nivel de comunidad de la teoría del óptimo fisiológico de Pianka. Esta relación permite monitorear la influencia de los cambios climáticos, dado que la variación ambiental y las zonas de mortalidad y no mortalidad cambiarán con las variaciones predichas de los valores medios mensuales de la temperatura del aire.