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Results for “Journal of Parasitology Research”

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5 recordsLinked to original sources
USGS2011

Effects of environmental temperature on the dynamics of ichthyophoniasis in Juvenile Pacific Herring (Clupea pallasii)

The effects of temperature and infection by Ichthyophonus were examined in juvenile Pacific herring (Clupea pallasii) maintained under simulated overwinter fasting conditions. In addition to defining parameters for a herring bioenergetics model (discussed in Vollenweider et al. this issue), these experiments provided new insights into factors influencing the infectivity and virulence of the parasite Ichthyophonus. In groups of fish with established disease, temperature variation had little effect on disease outcome. Ichthyophonus mortality outpaced that resulting from starvation alone. In newly infected fish, temperature variation significantly changed the mortality patterns related to disease. Both elevated and lowered temperatures suppressed disease-related mortality relative to ambient treatments. When parasite exposure dose decreased, an inverse relationship between infection prevalence and temperature was detected. These findings suggest interplay between temperature optima for parasite growth and host immune function and have implications for our understanding of how Ichthyophonus infections are established in wild fish populations.

Journal of Parasitology Research↗
USGS2018

Museum metabarcoding: a novel method revealing gut helminth communities of small mammals across space and time

Natural history collections spanning multiple decades provide fundamental historical baselines to measure and understand changing biodiversity. New technologies such as next generation DNA sequencing (NGS) have considerably increased the potential of museum specimens to address significant questions regarding the impact of environmental changes on host and parasite/pathogen dynamics. We developed a new technique to identify intestinal helminth parasites and applied it to shrews (Eulipotyphla: Soricidae) because they are ubiquitous, occupy diverse habitats, and host a diverse and abundant parasite fauna. Notably, we included museum specimens preserved in various ways to explore the efficacy of using metabarcoding analyses that may enable identification of helminth symbiont communities from historical archives. We successfully sequenced the parasite communities (using 12S mtDNA, 16S mtDNA, 28S rDNA) of 23 whole gastrointestinal (GI) tracts. All GI tracts were obtained from the Museum of Southwestern Biology (MSB), USA, and from recent field collections, varying both in time since fixation (ranging from 4 months to 16 years) and preservation method (70% or 95% ethanol stored at room temperature, or flash frozen in liquid nitrogen and stored at -80°C). Our proof of concept demonstrates the feasibility of applying NGS techniques to authoritatively identify the parasite/pathogen communities within whole GI tracts from museum specimens of varying age and fixation, and the value of future preservation of host-associated whole GI tracts in public research archives. This powerful approach facilitates future comparative examinations of the distributions and interactions among multiple associated groups of organisms through time and space.

International Journal for Parasitology↗
USGS2001

Biography of Dr. John L. Fryer

There is probably no one in the fi sh health community who does not recognize the name of Professor John L. Fryer. Active in research for a period of more than 40 years, Dr Fryer has achieved internatio nal acclaim for his wor k on infectious diseases of Pacific salmon . The resea rch from his laboratory at Oregon State University (OSU) has spanned the disciplines of virology, parasitology, bacteriology, cell biology, immuno logy and fi sh physiology, result ing in more than 200 publications, two patents and recognition as one of the world's leading centres for researc h on infec tious diseases of salmon id fi sh.

Journal of Fish Diseases↗
USGS1941

Blood parasites of birds of the District of Columbia and Patuxent Research Refuge vicinity

Recently a number of surveys of blood parasites of birds have been made in different parts of this country by different workers, the general purpose of which was to further the knowledge of the distribution and pathogenicity of these protozoa. This paper treats the distribution of parasites found in sampling miscellaneous birds of the District of Columbia and vicinity and contains a preliminary report on the more important phase of the problem of pathogenicity.

Maryland↗
USGS2012

Digenean metacercariae of fishes from the lagoon flats of Palmyra Atoll, Eastern Indo-Pacific

Although many studies on the taxonomy of digenean trematodes of marine fishes have been completed in the Eastern Indo-Pacific (EIP) marine ecoregion, only a few have considered metacercarial stages. Here, the results are presented of a taxonomic survey of the digenean metacercariae of fishes from Palmyra Atoll, a remote and relatively pristine US National Wildlife Refuge located 1680 km SSW of Hawaii. Up to 425 individual fish were collected, comprising 42 fish species, from the sand flats bordering the lagoon of the atoll. Quantitative parasitological examinations of each fish were performed. Morphological descriptions of the encountered digenean metacercariae are provided, together with their prevalence, mean intensities, host and tissue-use. Up to 33,964 individuals were recovered representing 19 digenean metacercaria species from eight families. The species composition of digeneans in lagoon fishes at Palmyra Atoll is a subset of what has previously been reported for the EIP. Further, the large diversity and abundance of metacercariae reported in this study highlight the utility of including this group in future ecological research in the EIP marine ecoregion.

Journal of Helminthology↗