Annotated checklist of the freshwater fishes of continental and insular Costa Rica: additions and nomenclatural revisions

Based on a combination of intensive literature review, electronic database searches, re-identification of museum specimens and fieldwork, we hereby provide an updated checklist of the freshwater fishes of continental and insular Costa Rica. This checklist, systematically arranged at the ordinal and familial level, includes nomenclatural revisions, distributional information, and when appropriate, cross-references on the basis of Bussing (1998). According to our results, the native Costa Rican freshwater fish fauna is composed by 250 species, divided into 119 genera, 49 families and 19 orders; increasing in 108 the number of species originally reported by Bussing (1998). By far, the vast majority of these species, according to their supposed tolerance to salinity, are peripheral (63.2%), followed by secondary freshwater fishes (23.6%); only 13.2% are primary freshwater fishes. 24 species in this checklist appear to be endemic to Costa Rica. In addition to the native fauna 8 exotic species are reported

A new species of Urobatis (Myliobatiformes: Urotrygonidae) from the tropical Eastern Pacific.

Una nueva especie de raya redonda con espina, Urobatis pardalis sp. nov., es descrita a partir de material recolectado en las costas del Pacífico de Costa Rica. Esta nueva especie difiere de sus congéneres por el patrón de la coloración dorsal del disco y por varias relaciones de medidas. Se presenta una clave para la determinación taxonómica de las especies del género.A new species of round stingray, Urobatis pardalis sp. nov., is described from material collected in the Pacific coast of Costa Rica. This new species differs from its congeners by the color pattern of the dorsal surface and by several proportional measurements. A key to all species of the genus is provided.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR

Increased ventral striatal volume in college-aged binge drinkers

BACKGROUND Binge drinking is a serious public health issue associated with cognitive, physiological, and anatomical differences from healthy individuals. No studies, however, have reported subcortical grey matter differences in this population. To address this, we compared the grey matter volumes of college-age binge drinkers and healthy controls, focusing on the ventral striatum, hippocampus and amygdala. METHOD T1-weighted images of 19 binge drinkers and 19 healthy volunteers were analyzed using voxel-based morphometry. Structural data were also covaried with Alcohol Use Disorders Identification Test (AUDIT) scores. Cluster-extent threshold and small volume corrections were both used to analyze imaging data. RESULTS Binge drinkers had significantly larger ventral striatal grey matter volumes compared to controls. There were no between group differences in hippocampal or amygdalar volume. Ventral striatal, amygdalar, and hippocampal volumes were also negatively related to AUDIT scores across groups. CONCLUSIONS Our findings stand in contrast to the lower ventral striatal volume previously observed in more severe forms of alcohol use disorders, suggesting that college-age binge drinkers may represent a distinct population from those groups. These findings may instead represent early sequelae, compensatory effects of repeated binge and withdrawal, or an endophenotypic risk factor

Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Geographic Distribution of the San Juan Ichthyofauna of Central America with Remarks on its Origin and Ecology

The scientific study of fishes of the Great Lakes of Nicaragua began in 1864 with the description by Gunther of Heros labiatus (=Cichlasoma labiatum) from Lake Managua. Subsequently, Gunther reported on several other species collected in the Great Lakes by Captain J. M. Dow. Astorqui (1967) reviewed the sparse ichthyological literature dealing with Nicaraguan fishes and pointed out the paucity of recent studies. Since then Villa (1971) has produced a provisional list of the freshwater and brackish water fishes of Nicaragua and Astorqui (1972) has analyzed the ichthyofauna of the Great Lakes Basin. Riedel (1972) discussed the geological history of the Great Lakes in relation to the composition and evolution of its fish fauna

A new species of poeciliid fish, Poeciliopsis santaelena, from Peninsula Santa Elena, Area de Conservación Guanacaste, Costa Rica

An undescribed freshwater fish was recently discovered during a biological inventory of Area de Conservación Guanacaste, northwestern Costa Rica. This new species of Poeciliopsis is closely related to a group of widespread species of small spotted fishes designated as the Poeciliopsis gracilis complex in this study. The complex extends on both versants from southern Mexico to Nicaragua, and with this new finding, extends into Costa Rica. The new species is distinguished from its Central American relatives by its lack of lateral and ventral markings, higher pectoral and caudal-fin counts and more posterior placement of the dorsal fin. Poeciliopsis santaelena is endemic to the Río Potrero Grande, a river whose flow is reduced to just a few pools during the long dry season and flows fully only during very rainy weather. It is just another in a growing list of threatened or endangered species found in this unique peninsular environment. Rev. Biol. Trop. 56 (2): 829-838. Epub 2008 June 30.<br>Recientemente se descubrió una especie no descrita de pez dulceacuícola durante un inventario biológico en Area de Conservación Guanacaste (ACG) en el noroeste de Costa Rica. Esta especie nueva del género Poeciliopsis tiene un parentesco cercano con un grupo de especies con puntos en los costados ampliamente distribuidas que se designan en este informe como complejo de Poeciliopsis gracilis. El complejo se extiende en ambas vertientes desde el sur de México hasta Nicaragua. La especie nueva se distingue de sus parientes centroamericanos por su falta de manchas negras laterales y ventrales, mayor número de radios pectorales y caudales, y posición más posterior de la aleta dorsal. Poeciliopsis santaelena, especie endémica de un sólo riachuelo intermitente, es una especie más in la lista de especies en peligro que se encuentra en este peculiar ambiente peninsular

Gymnothorax phalarus, a new eastern Pacific moray eel (Pisces: Muraenidae)

Gymnothorax phalarus is described from 23 individuals taken in trawl and dredge collections made on the Pacific coast of Costa Rica. The new species is nearly always syntopic with a similar species, Gymnothorax equatorialis. The new moray is distinguished by its white-spotted pattern, uniserial, slightly serrated teeth in adults, four infraorbital pores and mean vertebral formula of 6-58-140. Of the total of 21 valid species of morays recorded from the Pacific coast of Costa Rica, only the new species and G. equatorialis form part of the trawl fishery as the remainder are almost entirely restricted to nearshore rocky habitats. The known range of G. phalarus is from Baja California to Peru.<br>Gymnothorax phalarus se describe con base en 23 individuos de colecciones hechas por redes de arrastre y dragas en la costa Pacífica de Costa Rica. La especie nueva es casi siempre sintópica con la especie similar, Gymnothorax equatorialis. La nueva morena se distingue por su patrón de puntos blancos, dientes ligeramente aserrados y uniseriales en adultos, cuatro poros infraorbitales y MVF (Fórmula de Vértebras) de 6-58-140. México a Perú