The introduction of monogeneans with exotic freshwater fishes in Argentinean Patagonia.

G. VIOZZI; R. VEGA; A. WAICHEIM; C. RAUQUE; M. GONZALEZ

Río de Janeiro

Workshop; VII International Symposium on Monogenea; 2013

The main motivations for introductions of fishes around the world have been esthetical,recreational and to promote aquaculture. Also, accidental introductions due to the escape orrelease of aquarium fish are increasing. The Patagonic ictiogeographic region is characterized bylow species diversity, with 27 species of freshwater fishes. Fourteen of these species are exoticand have been intentionally or accidentally introduced into Patagonia, having established selfsustainingpopulations. Seven out of these 14 are salmonids. The non-salmonid species haverestricted distributions, mainly in the northern limit of Patagonia. Evidences of monogeneantransfer from African to American cichlids and vice versa have been reported in Mexico. Also,species of Dactylogyrus from the invasive common carp have been reported parasitizing nativefishes in different places of the world. The aim of the present study was to detect introduction ofmonogenean species along with their exotic fishes in Northern Patagonia. Introduced fishes ofthe families Salmonidae (Salmo trutta, Oncorhynchus mykiss, Salvelinus fontinalis, Salmo salar),Cyprinidae (Cyprinus carpio), Characidae (Cheirodon interruptus), Anablepidae (Jenynsiamultidentata), Poecilidae (Cnesterodon decemmaculatus), and Callichthyidae (Corydoraspaleatus) were captured in the Negro, Neuquén and Limay rivers, transported alive (except forsalmonids) to the laboratory and examined for parasites. Eight non-native species ofmonogenean were registered: Dactylogyrus extensus and Dactylogyrus anchoratus from the gillsand Pseudacolpenteron sp. from pores of the scales of the lateral line system of Cyprinus carpio;Philocorydoras paleatus from the gills of Corydoras paleatus; Ancyrocaphalinae sp.1,Ancyrocephalinae sp.2 from the gills, and Gyrodactylus sp.1 from the skin of Cheirodoninterruptus; and Gyrodactylus sp.2 from the tegument of Jenynsia multidentata. The alienmonogenean species outnumber the native ones. Although Patagonian freshwater fishes havebeen extensively studied for parasites, only 7 native monogeneans have been reported:Philureter trigoniopsis and Gyrodactylus sp. from Galaxias maculatus, and Acolpenteron australe,Duplaccessorius andinus, Cryptocephalum petreum and Cryptocephalum spiralis fromPercichthys trucha. Monogeneans have better opportunities to colonize new environmentsbecause they do not require an intermediate host, and despite of the high host-specificity of theseparasites, the findings indicate the possibility of transmission to native Patagonian hosts.