Geology topics

J.A. Perry

Publications and source records attributed to J.A. Perry.

2 recordsLinked to original sources

USGS2004

High doses of corticosteroid suppress resistance to Ichthyophonus in starry flounder

Application of pharmacological doses of the corticosteroid dexamethasone phosphate to starry flounder Platichthys stellatus resulted in a predisposition to clinical ichthyophoniasis and a progression from latent Ichthyophonus infections to patent, histologically identifiable infections. Among Ichthyophonus -challenged starry flounder, the prevalences of clinical infections and histologically identifiable infections were significantly greater in two groups that received dexamethasone (100% and 31%, respectively) than in the respective control groups (8% and 0%). Proliferation of Ichthyophonus infections in corticosteroid-treated groups may have resulted from suppression of the cellular immune response that typically follows corticosteroid application; however, further studies are needed to determine whether these effects occur at lower, physiological concentrations of corticosteroids.

Journal of Aquatic Animal Health↗

USGS2002

Elevated temperature exacerbates Ichthyophonus infections in buffalo sculpin

High incidences of Ichthyophonus hoferi, a parasite primarily of marine and estuarine fishes, have recently been reported in rockfishes and Pacific herring from the eastern North Pacific (Kent et al 2001, Hershberger et al 2002). Taxonomic position of I. hoferi remains unresolved, but recent phylogenetic studies have grouped the organism with Dermocystidium, Psorospermium, the rosette agent of salmonids, and Rhinosporidium in the Mesomycetozoa, a novel clade of protists near the animal-fungal divergence (Herr et al 1999). Genetic differences among isolates from the east coast of North America indicate that more than one species of Ichthyophonus exist (Rand et al 2000), and different species have likely been assigned the same name based on morphological characteristics. Therefore, hereafter in this manuscript, the organism will be referred to as Ichthyophonus .

Fish Health Newsletter↗