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Method for inducing saprolegniasis in channel catfish

Journal of Aquatic Animal Health

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Abstract

A method was developed to uniformly and systematically induce saprolegniasis in channel catfish Ictalurus punctatus. Three different methods for inducing saprolegniasis were evaluated in waters containing known zoospore concentrations of Saprolegnia parasitica (1) low-temperature shock to induce immunosuppression: (2) physical abrasion stress; and (3) a combination of both low temperature shock and abrasion stress. Low-temperature shock or abrasion stress alone were not effective for inducing saprolegniasis. Only 10% of fish stressed by low-temperature shock alone became infected. No fish receiving abrasion stress treatments alone became infected even though these fish were subject to significant abrasion and dewatering stress. A combination of low-temperature and abrasion stress, however, was sufficient to induce saprolegniasis in 100% of fish tested and resulted in 90% mortality. No fish became infected in the positive control group (exposed to zoospores of S. Parasitica without stress) or in the negative control group. The combined-stress method should enable researchers to induce saprolegniasis in channel catfish at will to study its pathogenesis or to test the efficacy of candidate antifungal treatments. In conducting efficacy studies, therapeutic treatments must begin immediately when the first signs of saprolegniasis are observed because the disease progresses quickly and is deadly.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Method for inducing saprolegniasis in channel catfish
Series title:
Journal of Aquatic Animal Health
Volume
10
Issue:
1
Year Published:
1998
Language:
English
Contributing office(s):
Upper Midwest Environmental Sciences Center
Description:
pp. 62-68
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Aquatic Animal Health
First page:
62
Last page:
68
Number of Pages:
7