Effects of the pathogenic water mold Saprolegnia ferax on survival of amphibian larvae

• Published in: Diseases of aquatic organisms Vol. 83; no. 3; pp. 187 - 193
• Main Authors: ROMANSIC, John M, DIEZ, Kristin A, HIGASHI, Elise M, JOHNSON, James E, BLAUSTEIN, Andrew R
• Format: Journal Article
• Language: English
• Published: Oldendorf Inter-Research 25.02.2009
• Subjects: Ambystoma macrodactylum; Animal, plant and microbial ecology; Animals; Anura - microbiology; Applied ecology; Biological and medical sciences; Caudata; Conservation, protection and management of environment and wildlife; Freshwater; Fundamental and applied biological sciences. Psychology; Infection - mortality; Infection - veterinary; Larva - microbiology; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Pseudacris regilla; Rana cascadae; Saprolegnia - physiology; Saprolegnia ferax; Urodela - microbiology; Water Microbiology; Stramenopila; Endangered species; Ambystoma macrodactylum; Caudata; Water mold; Saprolegnia; Amphibia; Parasite; Salientia; Zoopathogen; Saprolegnia ferax; Oomycota; Survival; Rana cascadae; Infection; Freshwater environment; Mycoparasite; Vertebrata; Larva; Pathogenic; Ranidae; Environmental monitoring; Rana aurora; Amphibian; Pseudacris regilla
• ISSN: 0177-5103; 1616-1580
• DOI: 10.3354/dao02007

Infectious diseases are a significant threat to worldwide biodiversity. Amphibian declines, a significant part of current biodiversity losses, are in many cases associated with infectious disease. Water molds are one group of pathogens affecting amphibians on a worldwide basis. Although water molds have been studied extensively for their effects on host embryos, little information is available about how they affect post-embryonic amphibians. We tested the effects of one species of water mold, Saprolegnia ferax, in a comparative study of larvae of 4 amphibian species: Pseudacris regilla (Pacific treefrog), Rana cascadae (Cascades frog), Ambystoma macrodactylum (long-toed salamander), and R. aurora (red-legged frog). S. ferax can kill amphibians at the embryonic and juvenile life history stages, depending on the amphibian species. In the present study, a 1 wk exposure to S. ferax killed P. regilla larvae and a 2 wk exposure killed R. aurora larvae. Larvae of the other host species were unaffected after 1 wk of exposure to S. ferax. Our results suggest that S. ferax can kill amphibian larvae and further suggest that evaluation of how pathogens affect amphibians at the population level requires investigation at various life stages.