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The impact of invasive fish on an endemic Cyprinodon species flock (Teleostei) from Laguna Chichancanab, Yucatan, Mexico

Por Strecker, Ulrike

Ecology of Freshwater Fish, 2006(15):408-418 2006


" Species that invade a new environment often may lead to population declines of endemic species. Here I document the invasions of an African cichlid (genus Oreochromis) in 1988 and the Mexican Astyanax fasciatus (Characidae) in 1996 into Laguna Chichancanab (Yucatan, Mexico), and the impact on an endemic Cyprinodon species flock and the poeciliid Gambusia sexradiata. After the invasion of Astanax fasciatus, their relative abundances decreased enormously, most likely caused by predation on the fry. One species, Cyprinodon simus, might have even gone extinct or just occurs in extremely reduced numbers. Furthermore, it was observed that the percentage abundance of the detritivorous Cyprinodon beltrani increased significantly, in contrast to all other Cyprinodon species. This study also revealed that infestation by metacercaria (black spots) of an ectoparasitic trematode and of an endoparasitic nematode increased in the Cyprinodon spp. following the introduction of Oreochromis. Whereas the infestation by trematodes decreased after a period of 6 years, the prevalence and intensity of infestation by nematodes stayed at a high level. In contrast, in G. sexradiata the parasite load remained always very low "

Idioma: English

Strecker, Ulrike. 2006. "The impact of invasive fish on an endemic Cyprinodon species flock (Teleostei) from Laguna Chichancanab, Yucatan, Mexico". Ecology of Freshwater Fish. 2006(15):408-418 (ffm00577) (resumen)