Comparative Study of the Age Classes of Two Species of Philophthalmus Looss, 1899 (Philophthalmidae: Philophthalminae)

摘要

abstract: The growth patterns of adult Philophthalmus andersoni and Philophthalmus larsoni reared in domestic chickens from metacercariae, were compared at 10, 20, 70, and 175 d postexposure. Generally, P. andersoni continued to grow throughout all age classes, while P. larsoni reached its greatest length (4.3 mm) at 70 d and showed no further growth at 175 d. Most standard descriptive measurements (body length, forebody length, size of oral sucker, size of pharynx, length of esophagus, size of acetabulum, size of testes, size of ovary, size of posttesticular space, length of cirrus sac, size of seminal receptacle, size of vitelline follicles, size of eggs) were typically different when comparing P. andersoni and P. larsoni, but often there was overlap between the ranges of age classes within each species, as well as between the age class of the 2 species. We found that there were 2 measurements that had noticeably less overlap between these 2 species than the others listed: (1) length of esophagus; and (2) length of the posttesticular space. Natterophthalmus is synonymous with Philophthalmus, and the characteristics previously used to distinguish Natterophthalmus from Philophthalmus are discussed.