INTESTINAL PARASITES OF FRANCISCANAS, Pontoporia blainvillei (Cetacea: Pontoporiidae) FROM PROVINCIA DE BUENOS AIRES, ARGENTINA

JULIANA MARIGO ; MARIA FERNANDA NEGRI ; MARÍA NATALIA PASO VIOLA; CLADIA PORTES SANTOS ; LUIS H. CAPPOZZO.

San Pablo

Congreso; Congresso "Todos pela Conservação"; 2007

Secretaria de Medio Ambiente

Intestinal parasites OF FRANCISCANAs, Pontoporia blainvillei (Cetacea: Pontoporiidae) from BUENOS AIRES PROVINCIA, ARGENTINA. Marigo, J1,2,3.; Negri,4 M. F.; Pasoviola,4 N.; Vicente2, A.C.P.; Santos, C.P1.;  Cappozzo,4 H. L. 1Laboratório de Avaliação e Promoção da Saúde Ambiental, Departamento de Biologia; 2 Laboratório de Genética Molecular e Microorganismos, Departamento de Genética, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, Manguinhos, Rio de Janeiro, 21045-900, Brazil. 3Projeto BioPesca, Rua Paraguai 241, Praia Grande, São Paulo, 11702-070, Brazil jumarigo@biopesca.org.br. 4Laboratorio de Ecología, Comportamiento y Mamíferos Marinos (LECyMM), Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” y Estación Hidrobiológica de Puerto Quequén. Buenos Aires, Argentina. cappozzo@macn.gov.ar Pontoporia blainvillei Gervais & d’Orbigny, 1844 is a small cetacean, common named franciscana, which is endemic to South Atlantic waters, occurring from Peninsula Valdez, Argentina (42°35’S) to Espírito Santo State, Brazil (18°25’S). The trematode Synthesium pontoporiae (Raga, Aznar, Balbuena & Dailey, 1994) was previously referred parasitizing the small intestine of P. blainvillei along its distribution. In the present study, we analyzed the intestines of 17 franciscanas accidentally captured in fishing nets from three localities south of Buenos Aires Provincia, Argentina. During the necropsy, the intestines were removed and fixed in formalin to be analyzed in the laboratory. The small intestine was divided in five equal-sized sections; these portions were opened with scissors inside a plastic tray, the contents were washed in a sieve (mesh =150mm) and examined under a stereomicroscope. The helminths collected were counted and stored in 70% alcohol. The mean length of the small intestine was 30m (±6). Approximately 50 % of the dolphins were mature with total body length varying from 98.3 to 158.5cm with average of 123.4cm (±17). All parasites were found in the first portion of the intestine, close to the stomach. A total of 2,300 adult specimens of Synthesium pontoporiae were obtained. The prevalence of S. pontoporiae was 88.2% and the number of parasites per host varied from 5 to 450 with mean intensity of 135 (±151). Fish consumed by these franciscanas were Cynoscion guatucupa (76.9%), Trachurus lathami (30.7%), Engraulis anchoita (23%) and Raneya fluminensis (15.4%). The high prevalence and mean intensity of S. pontoporiae were similar to previous studies in Argentinean waters and this maybe related to temperature-salinity profiles associated to fransciscana’s diet. The study of these ecological factors may contribute significantly to the use of parasites for stock identification. Financial support: Cetacean Society International, Instituto Oswaldo Cruz (IOC-FIOCRUZ), PIP/02193,GV04B-304