Emended description and redetermination of Sarwaria caballeroi n. comb. (Nematoda: Ostertaginae) with Details of the Synlophe and Esophageal Characters.

Authors: Hoberg, Eric; Abrams, Arthur

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2007
Publication Date: 2/1/2007
Citation: Hoberg, E.P., Abrams, A. 2007. Emended description and redetermination of Sarwaria caballeroi n. comb. (Nematoda: Ostertaginae) with Details of the Synlophe and Esophageal Characters. Journal of Parasitology. 93:1140-1150.

Interpretive Summary: Abomasal nematodes remain among the most economically important parasites in ruminants throughout the world. Aspects of their taxonomy, however, remain poorly defined and contribute to mis-identification and a confused understanding of host and geographic distributions, and patterns of disease. Our studies of the nematode Spiculopteragia caballeroi contribute to resolution of the taxonomy for genera within the subfamily Ostertagiinae, the primary abomasal parasites in ungulates. Among genera of the ostertagiine nematodes, structural attributes of Spiculopteragia caballeroi are consistent with criteria which diagnose the genus Sarwaria. Our studies contribute further to validation of the genus Sarwaria. Thus, the ostertagiines are represented by 10 valid genera including those characterized by a bursal formula of 2-2-1 (Cervicaprastrongylus, Hyostrongylus, Mazamastrongylus, Spiculopteragia, and Teladorsagia in addition to Sarwaria), and those in which the lateral bursal rays describe a 2-1-2 pattern (Camelostrongylus, Longistrongylus, Marshallagia, and Ostertagia). Resolution of generic diversity among these parasites is a foundation for defining and exploring evolutionary relationships for hosts and parasites and the mechanisms involved in their maintenance and dissemination in the context of environmental change.

Technical Abstract: : Among genera of the ostertagiine nematodes, structural attributes of Spiculopteragia caballeroi are consistent with criteria which diagnose the genus Sarwaria. Specifically the following characters are compatible with referral to this genus: (1.) species characterized by monomorphic males; (2.) tapering lateral synlophe in the cervical zone; (3.) minuscule, thorn-like cervical papillae; (4.) length of Ray “4” < Ray “5”; (5.) relatively thick or robust Ray “4”; (6.) a substantially reduced dorsal lobe and dorsal ray that are disposed or curved ventrally relative to Rays “8”; and (7.) a broad, laterally inflated dorsal lobe. Consequently, we propose Sarwaria caballeroi n. comb., and provide further validation for the genus Sarwaria. Additionally, we propose that the ostertagiines are represented by 10 valid genera including those characterized by a bursal formula of 2-2-1 (Cervicaprastrongylus, Hyostrongylus, Mazamastrongylus, Spiculopteragia, and Teladorsagia in addition to Sarwaria), and those in which the lateral rays describe a 2-1-2 pattern (Camelostrongylus, Longistrongylus, Marshallagia, and Ostertagia).