|Pilitt, Patricia - Pat|
Submitted to: Society of Washington Journal of Helminthological
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/1998
Publication Date: N/A
Citation: N/A Interpretive Summary: Strongyloid nematodes are a major cause of morbidity and mortality in equines in the United States. Resistance to antiparasitic drugs (currently the only means of controlling the nematode disease in horses) is common and alternative control methods for these parasites are needed to protect horses in the United States. Considerable research is underway worldwide to develop improved control strategies. This research requires the identification of the more than 51 nematode species that are parasitic in the large intestine and caecum of horses. This report provides new information for differentiating 2 structurally similar species, Coronatus coronatus and C. sagitattus. The latter is rarely reported and has probably been misidentified as the former. The improved capability of separating these species will improve the accuracy of reports of drug trials and other control measures for these pathogens of horses.
Technical Abstract: An increased interest worldwide in small strongyles of horses has prompted a revision of the systematics in order to support research on improving antiparasitic chemotherapy, biocontrol and other management practices. A 1997 international workshop developed a revised list of recommended names for 51 recognized species of Cyathostominea and indicated problems in differentiation of some species, including Coronocyclus coronatus (Looss, 1900) and C. sagittatus (Kotlan, 1920). These morphologically similar species are members of Coronocyclus Hartwich, 1986, a genus with prominent and sclerotized external leaf-crown supports which are separated from the buccal capsule. The species can be separated by differences in the shape of the buccal capsule, shape of the buccal capsule wall in optical section, point of insertion of elements of the internal leaf crown, and dorsal ray of the male. Drawings and photomicrographs are presented illustrating the characteristics useful for differentiating C. coronatus and C. sagittatus.