As
part of a 1999 water quality experiment, specimens of kidney, gill, liver, pancreatic
tissue, and intestinal tract from four ammonia exposure treatment groups of
juvenile Lost River Suckers were evaluated by light microscopy for abnormalities.
Differential leukocyte counts were performed on blood smears from the same groups.
The California - Nevada Fish
Health Center assisted the principal investigator, Elaine Snyder-Conn (Contaminant
Specialist, Klamath Basin Fish and Wildlife Office), in a 1999 cooperative study
on the effects of chronic,sub-lethal ammonia exposure on juvenile Lost River
Suckers. Adverse water quality in Klamath Lake has been identified as one of
several factors affecting this endangered species.
Two
abnormalities, gill epithelium separation and hyaline droplets in kidney tubule
cells, were observed in the study fish. No abnormalities were observed in
liver, intestine, or pancreatic tissue from any treatment group specimen.
Approximately 10 % of each treatment group showed mild inflammation of the
intestine. We have observed such inflammatory changes in juvenile chinook
during their smolt migration in warm water conditions and speculate that it
is related to membrane damage. Separation of the gill lamellar epithelium
was seen in 31 - 86 % of the various sample groups. There appeared to be an
inverse relationship between ammonia concentration and severity of this gill
lesion. The control (0.006 ppm ammonia) fish demonstrated both the highest
prevalence and severity of all the sample groups followed by the low (0.115
ppm) group. In addition to epithelium separation, epithelial cell swelling
was seen in 14 % of the affected control gills. Mucus discharge from goblet
cells was commonly observed in gills from all the groups and may be a reaction
to the initial contact with fixative.
Learn More by Reading the Full Report:Snyder-Conn, E., Holt, R., U of Wyoming Dept. of Zoology and Physiology, Effects of Ammonia Exposure on Lost River Sucker Fish, USFWS. Klamath Basin Refuges. 1999.
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