We surveyed the population status of the Neotropical toad genus Atelopus, and document recent catastrophic declines that are more severe than previously reported for any amphibian genus. Of 113 species that have been described or are candidates for description, data indicate that in 42 species, population sizes have been reduced by at least half and only ten species have stable populations. The status of the remaining taxa is unknown. At least 30 species have been missing from all known localities for at least 8 yr and are feared extinct. Most of these species were last seen between 1984 and 1996. All species restricted to elevations of above 1000 m have declined and 75 percent have disappeared, while 58 percent of lowland species have declined and 38 percent have disappeared. Habitat loss was not related to declines once we controlled for the effects of elevation. In fact, 22 species that occur in protected areas have disappeared. The fungal disease Batrachochytrium dendrobatidis has been documented from nine species that have declined, and may explain declines in higher elevation species that occur in undisturbed habitats. Climate change may also play a role, but other potential factors such as environmental contamination, trade, and introduced species are unlikely to have affected more than a handful of species. Widespread declines and extinctions in Atelopus may reflect population changes in other Neotropical amphibians that are more difficult to survey, and the loss of this trophic group may have cascading effects on other species in tropical ecosystems.
RESUMENExaminamos el estado poblacional de las ranas neotropicales del género Atelopus y documentamos disminuciones catastróficas recientes, las más drásticas señaladas para cualquier género de anfibios. De las 113 especies que han sido descritas o son candidatas para ser descritas, los datos poblacionales indican que en 42 especies, las poblaciones han sido reducidas por lo menos a la mitad y solamente diez especies tienen poblaciones estables. El estado de los taxa restantes es desconocido. Por lo menos 30 especies no han sido vistas en al menos ocho años de todas las localidades conocidas, y se teme que se hayan extinguido La mayoría de estas especies desaparecieron entre 1984 y 1996. Todas las especies con
SPECIAL SECTION Declines and Extinctions of Atelopus 191rangos altitudinales de 1000 m o superiores han sufrido disminuciones poblacionales, el 75 por ciento de estas ha desaparecido del todo. El 58 por ciento de las especies de bajura han sufrido disminuciones, mientras que el 38 por ciento ha desaparecido del todo. La pérdida de hábitat, no fue relacionada con las disminuciones una vez que se controló el efecto de altura en los análisis. De hecho, unas 22 especies que tienen poblaciones dentro deáreas protegidas han desaparecido. El hongo quítrido Batrachochytrium dendrobatidis estuvo presente en nueve especies que han experimentado disminuciones y puede explicar desapariciones en especies que ocupan hábitats no perturbados a mayores elevac...
An epizootic of fibropapillomas in green turtles Chelonia mydas (Reptilia: Testudines: Cheloniidae) has occurred throughout the Caribbean since the mid‐1980s. Similar epizootics in Hawaii and Florida began 5 years earlier. All may be part of a panzootic. The 125 Caribbean cases greatly expand the known range of these epizootics. All the tumors we examined had spirorchiid (Digenea) eggs. Few turtles we examined with tumors were emaciated. Additional tumors quickly erupted in some captive turtles, whereas tumors of others remained unchanged for 1 year. The turtle leech Ozobranchus branchiatus (Hirudinea: Ozobranchidae) was associated with only three green turtles with fibropapillomas.
In order to investigate the possible presence of the chytrid fungus Batrachochytrium dendrobatidis (Chytridiomycota: Chytridiales) in frogs (Amphibia: Anura) of Colombia, we made a retrospective examination of formalin-fixed specimens preserved in natural history collections. Using the staining technique of hematoxylin and eosin to identify B. dendrobatidis in histological slices, we found evidence of the fungus in 3 of the 53 frog species examined from a total of 672 specimens collected in 17 departments within Colombia between 1968 and 2006. The infected specimens were found dead or dying in recent years in high elevation sites, suggesting that chytridiomycosis (the disease caused by the fungus) may represent a significant threat to Colombian amphibians. We conclude that a more extensive search for B. dendrobatidis in museum specimens and wild-caught frogs should be undertaken as soon as possible, using both histological and molecular genetic techniques, in order to further characterize the geographic and taxonomic extent of infections of B. dendrobatidis.
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