An Emendation of Pneumatophilus Odhner, 1910 (Trematoda: Plagiorchiidae) and an Evaluation of Specific Characters of the Genus

Abstract

Based on material from Louisiana snakes, the genus Pneumatophilus Odhner, 1910, is emended to include the possession of two genital pores. An evaluation of the specific characters is presented and evidence presented for considering P. foliaformis and P. leidyi synonyms of P. variabilis (Leidy, 1856). Leidy (1856) described Distomum variabilis from the lung of Natrix sipedon. Pratt (1903) gave a more extensive description of this species and erected the genus Renifer to include it. Odhner (1910) created the genus Pneumatophilus with P. variabilis (Leidy, 1856) as the genotype. Talbot (1934) added P. foliaformis, and Byrd and Denton (1937) P. leidyi. Yamaguti (1958) suggested that Renifer elongatus Pratt, 1903, be transferred to Pneumatophilus but the present author believes it is more like species of Lechriorchis Stafford, 1905. Presently, the genus Pneumatophilus is characterized as having a common genital pore, but a study of 85 specimens from the author's collection and several collected by Byrd and Talbot revealed two genital pores which were evident in both whole mounts and sections (Fig. 1). To include that feature the genus is emended as follows. Pneumatophilus Odhner, 1910, emend. With characters of the Styphlodorinae. Body flattened, somewhat attenuated anteriorly, broadly rounded posteriorly. Cuticle with heavy spines. Acetabulum preequatorial, larger than oral sucker. Pharynx present. Esophagus short. Ceca extend to or just beyond testes. Genital pores separate, median, just posterior to intestinal bifurcation, female pore in advance of male pore. Testes symmetrical, medial or posterior to cecal ends, postequatorial. Cirrus sac moderate in size. Seminal vesicle tubular and sinuous. Ovary submedian, posterolateral to acetabulum. Vitellaria lateral, in anterior half of body. Uterus with descending and ascending limbs between testes, and loops filling posttesticular space. Metraterm weakly muscular. Adults parasitic in lungs and trachea of snakes. Received for publication 19 April 1968. *Present address: Department of Parasitology, Tulane University, School of Tropical Medicine and Public Health, New Orleans, Louisiana. At pre ent the genus Pneumatophilus is represented by three species in the United States: P. variabilis (Leidy, 1856), P. foliaformis Talbot, 1934, and P. leidyi Byrd and Denton, 1937. Table I gives a comparison of the published data on these species and that from material collected in this study. It can be seen that the measurements given for the three species fall well within the range of the material from this study. Talbot considered length and position of the cirrus sac and ratio of the suckers to be of specific value. Table I shows the difference in cirrus sac length in the species concerned is not significant. The cirrus sac was described as vertical in P. foliaformis. In the present material the cirrus sac coursed vertically in 52 of 78 specimens and marginal in the other 26. Obviously the position of this structure in FIGURE 1. Sagittal section showing female pore and cirrus. fp, female pore; c, cirrus. X 115.