Ichthyophonus sp. Infection in Opaleye (Girella nigricans)

Veterinary Pathology
By: , and 



Over a 3-year-period, 17 wild-caught opaleye (Girella nigricans) housed in a public display aquarium were found dead without premonitory signs. Grossly, 4 animals had pinpoint brown or black foci on coelomic adipose tissue. Histologically, liver, spleen, heart, and posterior kidney had mesomycetozoan granulomas in all cases; other organs were less commonly infected. Four opaleye had goiter; additional substantial lesions were not identified. Granulomas surrounded melanized debris, leukocytes, and mesomycetozoa represented by folded membranes (collapsed schizont walls), intact schizonts (50- to >200 µm in diameter with a multilaminate membrane), plasmodia (budding from schizonts or free in tissue), or rarely germinal tubes (budding from schizonts). Ichthyophonus was grown from fresh tissues in tissue explant broth cultures of the heart, liver, and/or spleen. Polymerase chain reaction using 18S ribosomal DNA primers amplified a 1730-bp region, and the DNA sequence was most similar to Ichthyophonus hoferi, which is often associated with freshwater aquaculture fish.
Publication type Article
Publication Subtype Journal Article
Title Ichthyophonus sp. Infection in Opaleye (Girella nigricans)
Series title Veterinary Pathology
DOI 10.1177/0300985819900015
Volume 57
Issue 2
Year Published 2020
Language English
Publisher SAGE Journals
Contributing office(s) Western Fisheries Research Center
Description 5 p.
First page 316
Last page 320
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