Publications

The protistan parasite Ichthyophonus sp. occurs in coastal populations of Pacific Herring Clupea pallasii throughout the northeast Pacific region, but the route(s) by which these planktivorous fish become infected is unknown. Several methods for establishing Ichthyophonus infections in laboratory challenges were examined. Infections were most effectively established after intraperitoneal (IP) inje

Although viral hemorrhagic septicemia virus (VHSV) typically occurs at low prevalence and intensity in natural populations of Pacific herring (Clupea pallasii) and other marine fishes in the Northeast Pacific Ocean, epizootics of the resulting disease (VHS) periodically occur, often in association with observed fish kills. Here we identify a list of principles, based on a combination of field stud

Echinoderms, positioned taxonomically at the base of deuterostomes, provide an important system for the study of the evolution of the immune system. However, there is little known about the cellular components and genes associated with echinoderm immunity. The 2013–2014 sea star wasting disease outbreak is an emergent, rapidly spreading disease, which has led to large population declines of astero

The progression of external signs of Ichthyophonus infection in Pacific herring Clupea pallasii Valenciennes was highly variable and asynchronous after intraperitoneal injection with pure parasite preparations; however, external signs generally persisted through the end of the study (429 days post-exposure). Observed signs included papules, erosions and ulcers. The prevalence of external signs pla

The protistan parasite Ichthyophonus occurred in populations of Pacific herring Clupea pallasii Valenciennes throughout coastal areas of the NE Pacific, ranging from Puget Sound, WA north to the Gulf of Alaska, AK. Infection prevalence in local Pacific herring stocks varied seasonally and annually, and a general pattern of increasing prevalence with host size and/or age persisted throughout the NE

Nanophyetus salmincola is a parasitic trematode, or flatworm, that infects salmonid fishes in the Pacific Northwest, including Washington, Oregon, and portions of California. The adult worm lives in the intestine of fish-eating birds and mammals. Eggs shed into the water hatch into miracidia which penetrate the first intermediate host, one of two species of snail Juga plicifera or J. silicula. Ase

Ichthyophonus hoferi (Plehn & Mulsow 1911) is a protistan parasite in the class Mesomycetozoea that infects a large range of marine and freshwater fish (Mendoza, Taylor & Ajello 2002; McVicar 2011). The broad host and geographic range, which includes both fresh and marine waters of the Northern and Southern Hemispheres, combined with a lack of distinguishing morphological characteristics, have pro

Viral erythrocytic necrosis (VEN) is a condition affecting the red blood cells of more than 20 species of marine and anadromous fishes in the North Atlantic and North Pacific Oceans. Among populations of Pacific herring (Clupea pallasii) on the west coast of North America the disease causes anemia and elevated mortality in periodic epizootics. Presently, VEN is diagnosed by observation of typical

Viral erythrocytic necrosis (VEN), originally termed piscine erythrocytic necrosis, is a condition that has been reported to affect the red blood cells (RBCs) of many species of marine and anadromous fishes in both the Atlantic and Pacific Oceans (Nicholson and Reno 1981; Smail 1982; Wolf 1988; Dannevig and Thorud 1999). Fish with VEN may develop a severe anemia that can reduce their stamina, pred

Ichthyophonus-infected Pacific herring, Clupea pallasii, were allowed to decompose in ambient seawater then serially sampled for 29 days to evaluate parasite viability and infectivity for Pacific staghorn sculpin, Leptocottus armatus. Ichthyophonus sp. was viable in decomposing herring tissues for at least 29 days post-mortem and could be transmitted via ingestion to sculpin for up to 5 days. The

Viral hemorrhagic septicemia virus (VHSV) is a target of surveillance by many state and federal agencies in the United States. Currently, the detection of VHSV relies on virus isolation, which is lethal to fish and indicates only the current infection status. A serological method is required to ascertain prior exposure. Here, we report two serologic tests for VHSV that are nonlethal, rapid, and sp

A combination of field surveys, molecular typing, and laboratory experiments were used to improve our understanding of the distribution and transmission mechanisms of fish parasites in the genus Ichthyophonus. Ichthyophonus spp. infections were detected from the Bering Sea to the coast of Oregon in 10 of 13 host species surveyed. Sequences of rDNA extracted from these isolates indicate that a ubiq