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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #155396
Title: NODULAR MASSES IN THE SWIMBLADDER AND VISCERAL FAT OF THE WALLEYE STIZOSTEDION VITREUM

Author
item Mitchell, Andrew
item OATS, DAVID - NEBRASKA GAME&PARKS COMM.

Submitted to: Nebraska Academy of Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2004
Publication Date: 4/14/2004
Citation: Mitchell, A.J., Oats, D.W. 2004. Nodular masses in the swimbladder and visceral fat of the walleye stizostedion vitreum. Nebraska Academy of Science. 29:25-27.

Interpretive Summary: This paper describes an unusual disease problem in walleye. Nodular masses that formed in the swim bladder and visceral fat appear to be a calcified cyst that in some cases was found to surround a nematode-like worm. No such cysts have previously been described from fish.

Technical Abstract: In April of 1990, a 1.8 kg walleye was found to contain hard cysts or nodules in the swimbladder and visceral fat. The nodules appeared to be formed around a worm-like mass. The nodules (10±5 mm in diameter) were composed of five to seven layers of tightly packed granules, that were at least partially calcified and the layers were held together by a sticky matrix. The outer coat of the nodule was convoluted with many protuberances. This is a first report of such cysts from fish and they appear to be similar to nodules induced by worms (encysted nematodes) in the intestines of swine and ruminants.