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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #236717
Title: Eustrongylides ignotus as a cause of mortality in commercially produced fish; Sunshine bass (Morone chrysops female X Morone saxatilis male) and other fishes in the southeastern USA

Author
item Mitchell, Andrew
item OVERSTREET, ROBIN - UNIV OF SOUTHERN MS
item GOODWIN, ANDY - UAPB

Submitted to: Annual Eastern Fish Health Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 2/23/2009
Publication Date: 4/27/2009
Citation: Mitchell, A.J., Overstreet, R., Goodwin, A. 2009. Eustrongylides ignotus as a cause of mortality in commercially produced fish; Sunshine bass (Morone chrysops female X Morone saxatilis male) and other fishes in the southeastern USA [abstrat]. 34th Annual Eastern Fish Health Workshop, April 27-May 1, 2009, Lake Placid, New York. p.66.

Interpretive Summary:

Technical Abstract: Conspicuous long, red, coiled nematodes Eustongylides ignotus locate in the body cavity or embed in the muscle of fish. These nematodes have a complex life cycle that involve aquatic birds as definitive hosts, oligochaetes as the first intermediate host, and usually fish as the second intermediate host. Eustongylides ignotus is reported to cause severe disease and high levels of mortality in aquatic birds but is rarely reported as a problem in fish. This report provides the first documented infections of the nematode parasite (E. ignotus) causing mortality in a commercially produced fish, the sunshine bass (a hybrid cross of female white bass, Morone chrysops, and male striped bass, Morone saxatilis). Sunshine bass are sold as both a food and recreational fish at a value of more than $20 M USD annually. A few thousand 3-cm sunshine bass were observed with distension of the body cavity and several were moribund. Up to four E. ignotus were removed from each infected fish. Eustongylides ignotus produced grossly visible abdominal distention and compressed and displaced organs and were often found wrapped around the intestinal tract. The nematodes were surrounded by an encapsulation composed of granulomatous inflammation, including scattered lymphocytes, and in areas where the capsule was not compressed against the wall of the coelom, it was less fibrous and often incorporated exocrine pancreas, associated ducts, and blood vessels. Also included is a report on a fish kill associated with E. ignotus and a harsh environmental condition in striped bass (an important commercial and sport fish) and the findings of E. ignotus in the fathead minnow, Pimephales promelas (a commercial baitfish) and the fountain darter, Etheostoma fontinalis (a federally-listed endangered species in the USA).