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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #243301
Title: A Novel Henneguya Species from Channel Catfish Described by Morphological, Histological, and Molecular Characterization

Author
item GRIFFIN, M - Mississippi State University
item POTE, L - Mississippi State University
item WISE, D - Mississippi State University
item GREENWAY, T - Mississippi State University
item MAUEL, M - Mississippi State University
item CAMUS, A - University Of Georgia

Submitted to: Journal of Aquatic Animal Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/11/2008
Publication Date: 9/1/2008
Citation: Griffin, M., Pote, L.M., Wise, D.J., Greenway, T.E., Mauel, M.J., Camus, A.C. 2008. A Novel Henneguya Species from Channel Catfish Described by Morphological, Histological, and Molecular Characterization. Journal of Aquatic Animal Health. 20(3):127-135.

Interpretive Summary: A new species Hennegya sutherlandi affecting channel catfish is described and the name Hennegya sutherlandi proposed. The parasite formed nodule, which are filled with spores, on the skin of the channel catfish. No immunological reaction is noted from the catfish. A blast search of the 18S small subunit rDNA sequence obtained by polymerase chain reaction amplification resulted in no identical sequence matches but indicated a close relationship to H. gurlei, H. ictaluri, and H. exilis. The unique host record, spore morphology, and novel genetic sequence derived from this isolate lead us to propose this isolate as a novel species.

Technical Abstract: Channel catfish Ictalurus punctatus from a commercial farming operation in the Mississippi Delta were submitted for examination for the presence of infection by the trematode Bolbophorus damnificus. The fish were instead found to possess skin nodules suggestive of Henneguya pellis, a species previously described in the blue catfish I. furcatus. Despite the dermal location and distribution of lesions, morphological characteristics of the myxospores were inconsistent with H. pellis. Spores possessed a lanceolate spore body 15.4 +/- 1.5 microm (mean +/- SD; range = 12.2-19.3 microm) in length and 5.5 +/- 0.6 microm (range = 4.5-6.8 microm) in width in valvular view, and 4.7 +/- 0.2 microm (range = 4.2-5.0 microm) in width in sutural view. Polar capsules were pyriform and unequal in both length and width and contained polar filaments with six coils. Polar capsules measured 6.1 +/- 0.8 microm (range = 4.0-7.9 microm) long and 1.7 +/- 0.3 microm (range = 1.0-2.2 microm) wide. The caudal appendages were 50.5 +/- 8.3 microm (range = 34.8-71.4 micorm) long and the total length of the spore was 65.9 +/- 8.6 microm (range = 48.2-90.0 microm). The "blister like" plasmodia were round or ovoid, up to 2 mm in diameter, and randomly distributed throughout the epidermis of the fish. Histologically, plasmodia were confined to the dermis and elicited no inflammatory reaction from the fish. A blast search of the 18S small subunit rDNA sequence obtained by polymerase chain reaction amplification resulted in no identical sequence matches but indicated a close relationship to H. gurlei, H. ictaluri, and H. exilis. The unique host record, spore morphology, and novel genetic sequence derived from this isolate lead us to propose this isolate as a novel species, H. sutherlandi.