J Vet Sci.  2007 Jun;8(2):147-149. 10.4142/jvs.2007.8.2.147.

Heterosporis anguillarum infections in farm cultured eels (Anguilla japonica) in Korea

• Joh SJ
• Kwon YK
• Kim MC
• Kim MJ
• Kwon HM
• Park JW
• Kwon JH
• Kim JH

• KMID: 1089665
• DOI: http://doi.org/10.4142/jvs.2007.8.2.147

Abstract

Ten eels (Anguilla japonica) from a fish farm in Korea were examined and diagnosed with a Heterosporis infection. The gross lesions on the trunk were uneven and the concave parts were pasty. Histopathologically, lyses of the trunk muscles, degenerative muscle fibers and the scattered spores were observed. The sporophorocyst (SPC) contained several spores with a variety of shapes. Some SPC were disrupted and the spores in the SPC were scattered in the muscle tissues. Macrophages existed near the scattered spores. Electron microscopy revealed special structures such as sporophorocyst containing various developmental parasitic stages such as meronts, sporonts, sporophorous vesicles and spores.

Keyword

Anguilla japonica; eels; Heterosporis anguillarum; microsporidia

MeSH Terms

*Anguilla
Animals
Aquaculture
Fish Diseases/*parasitology/pathology
Histocytochemistry/veterinary
Korea
Microscopy, Electron, Scanning Transmission/veterinary
Microsporidia/*growth & development/ultrastructure
Microsporidiosis/parasitology/pathology/*veterinary
Muscular Diseases/parasitology/pathology/*veterinary

Figure

• 

  Fig. 1 Optical micrographs of the muscle tissue infected with Heterosporis anguillarum. The tissue was cross-sectioned (A) and sectioned longitudinally (B). Multifocal sporocysts and hyaline degeneration are shown in the muscle fibers (arrowheads) and diffused severe lymphocytic inflammation can be seen in the muscle tissue. bar = 60 µm (A), 30 µm (B).

• 

  Fig. 2 Transmission electron micrographs of Heterosporis anguillarum. (A) A part of the sporophorocyst (SPC) of Heterosporis anguillarum embedded in the muscle tissue. SPC containing various stages of Heterosporis anguillarum. Presented the meronts (M), sporonts (SS), sporoblasts (Sb) and spore (S) in the sporophorous vesicles. (B) Mature spore (MS) and immature spore (IMS) are shown in the sporophorous vesicle. bar = 2 µm.

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