INVESTIGADORES
JARA fabian Gaston
artículos
Título:
Oomycete parasites in freshwater copepods of Patagonia: effects on survival and recruitment
Autor/es:
GARCIA RD; JARA F G; STECIOW M; REISSIG M
Revista:
DISEASES OF AQUATIC ORGANISMS
Editorial:
INTER-RESEARCH
Referencias:
Lugar: Oldendorf/Luhe; Año: 2018 vol. 2018 p. 123 - 134
ISSN:
0177-5103
Resumen:
Copepods are host of various oomycete parasite species, but the effects of pathogens on copepod populations have been rarely studied. This study aimed to characterize oomycete infection in the freshwater copepod Parabroteas sarsi, in a temporary pond in Patagonia (Argentina). A complete hydroperiod was monitored evaluating environmental variables as influencing factors in the oomycete infections. Laboratory experiments were performed to evaluate the susceptibility of infected copepods to consumption by predators. Although five species of copepods were present in the pond, only ovigerous P. sarsi females were parasitized by oomycetes. Two species were always found together, identified as: Aphanomyces ovidestruens and Pythium flevoense. Infections were detected at water temperatures greater than 20°C, with a positive relation between temperature and parasite prevalence. Infection occurred after a decrease in large filter feeder densities. The pathogens were not lethal to P. sarsi females in the short-term, but did produce the mortality of entire egg sacs, thus impacting negatively on the next recruitment. The mean prevalence of infection in females was 53%, reaching 83% in December. Females have the capacity to release an infected egg sac and generate a new one in few days. This infection does not affect the susceptibility of P. sarsi to the predator Notonecta vereetbrughenni. The decrease in female abundance registered towards the end of the hydroperiod could be related to a combination of factors that may have a differential effect on female survival, such as increasing temperature, the energy cost of egg sacs development and carrying, and oomycete infection.