Glypthelmins intestinalis ( Lucker, 1931 )

León, Pérez-Ponce De, 2008, Taxonomic revision of the genus Glypthelmins Stafford, 1905 (Platyhelminthes: Digenea: Plagiorchiida), parasites of anurans in the Americas, Zootaxa 1882, pp. 1-45 : 24-26

Glypthelmins intestinalis ( Lucker, 1931) , O´ Grady, 1987

( Figs. 12–15 )

Synonyms

Haplometrana intestinalis Lucker, 1931: 1 –7. Figs. 1–4 ; Haplometrana utahensis, Olsen, 1937b: 13 –28 (Description and life cycle); Waitz (1959: 385–387) [Sinonimizes Haplometrana utahensis with Haplometrana intestinalis ]; Haplometrana intestinalis, Brooks, 1977 ; Glypthelmins intestinalis , O´ Grady (1987: 52) [Transfers Haplometrana intestinalis to Glypthelmins intestinalis ]. Haplometrana intestinalis, Rannala (1990: 746–747) [Alozyme study]; Rannala (1991: 805–808) [Alozyme study]; Rannala (1992: 993 –1000) [Alozyme study].

Taxonomic summary

Type-host: Rana pretiosa .

Habitat: Intestine.

Type-locality: Bothell, King County, Washington, U.S.A.

Type specimens deposition: USNPC 29903.

Diagnosis: This species can be differentiated by the following unique traits: Body filiform with a ratio of body width/length longer than 7; esophagus longer than the ventral sucker; suctorial disc present on the ventral sucker; testes located in tandem; vitelline follicles extend from the ovarian region to the beginning of the last third of the body. Vitelline follicles are confluent in the post-testicular region.

Description: Body elongated, with round posterior and anterior ends. Ratio of the body width/length 1:7. Numerous scale-like spines present on the body tegument, in the anterior third of body. Oral sucker subterminal, rounded to oval, with several papillae on the buccal cavity. Ventral sucker rounded, smaller than oral sucker, preequatorial, and possesses a suctorial muscular disc bearing nine minute papillae around the disc. Oral sucker/ventral sucker ratio 1:0.58 in length and 1:0.58 in width. Mouth opens in the middle of oral sucker. Prepharynx conspicuous. Pharynx small, muscular, surrounded by medial glands that extend to the esophagus level. Oesophagus larger than oral sucker, thin. Caeca posteriorly to almost reach the end of body.

Testes oval to rounded, in tandem, and are located at mid-level of body, mostly intercaecal and sometimes overlapping the caeca ventrally. Cirrus pouch well-developed, large, and contains a bi-partite seminal vesicle, prostatic gland and unarmed and coiled cirrus. Cirrus opens into the genital pore that is immediately preacetabular. Ovary located sinistrally to the ventral sucker, ovoid, smaller than testes. Seminal receptacle ovoid, located postero-dorsal to ovary. Mehli’s gland inconspicouos, covered by the seminal receptacle. Uterus coiled, and the uterine loops transversally arranged, occupying the posterior region of body. In midbody, uterine loops intercaecal with some overlapping the caeca. Muscular metraterm almost as large as the cirrus, opening into the genital pore. Vitelline gland follicular, which is distributed into two fields along the caeca, from the level of the seminal receptacle to the posterior border of the posterior testis. Posteriorly to testes, follicles are confluent dorsally. Eggs operculated, yellow, and measure 48–58 µm long by 18–26 µm wide. Excretory vesicle “I” shaped extending to the level of posterior testis. Excretory pore terminal.

Host, geographic distribution and specimen deposition

Bufo boreas : U.S.A.: Idaho ( Waitz, 1959); Idaho, U.S.A., ( Waitz, 1961); “ U.S.A. ” ( Walton 1962).

Rana luteiventris : U.S.A.: Glacier National Park, Montana.

Specimen deposition: CNHE: 4692.

Rana pretiosa : Canada: Postill Lake, Kelowna, British Columbia, Coleman, Alberta (Holmes pers. comm in O´ Grady, 1987). Manning Park, Okanagan Falls, Wilgress Lake, Champion Lakes, Creston and Loon Lake, British Columbia (O´ Grady, 1987); Trail, British Columbia ( Rannala, 1990, 1991, 1992). U.S.A.: Bothell, Washington ( Lucker, 1931); Springville, Utah ( Olsen, 1937b); Idaho ( Waitz, 1959, 1961, 1962); North West ( Pratt & McCauley, 1961); Spokane County, Washington ( Current & Lang, 1975); Pelican Creek, Wyoming (O´ Grady, 1987); Northern Idaho ( Russell & Wallace, 1991). Specimen deposition: USNPC: 9025, 9026, 29903, 29904, 31021.

Rana pipiens : U.S.A.: Lake and Flathead counties, Montana (Holmes pers. comm in O´ Grady, 1987).

Rana pretiosa x Rana sylvatica : U.S.A.: Idaho ( Waitz, 1959).

Rana sylvatica : Canada: Gorge Creek, Alberta (Holmes com. per. in O´ Grady, 1987).

Life cycle

The life cycle of Glypthelmins intestinalis was elucidated by Olsen (1937b), Schell (1965), and Current & Lang (1975). Adults inhabit the intestine of Rana pretiosa , and the embrionated eggs are released to the environment with the feces and are ingested by snails ( Physa spp., Helisoma spp.. and Lymnaea spp.). Once inside the intestine of the first intermediate host, eggs hatch and the miracidium is released penetrating the stomach epithelium. Miracidium is then transformed to mother sporocyst and then daughter sporocysts are formed within each mother sporocyst. Each daughter sporocyst produces lophocerc xiphicocercariae that are released from the snail as free-living forms. Cercariae penetrate the skin of frogs, lose the caudal region and transform into metacercariae that encyst in the frog’s epidermis. Metecercaria are ingested when adult frogs feed upon their skin during molt.

GenBank

28S: AY875673 (1139 bp).

Figures

FIGURE 1. Phylogenetic hypothesis of Razo-Mendivil et al. (2006) showing the placement of Glypthelmins, Rauschiella and Choledocystus within the Plagiorchiforms. The Glypthelmins clade is marked in red.

FIGURES 2 – 5. Glypthelmins quieta (Stafford, 1900) Stafford, 1905. 2. Mature specimen, ventral view ex Rana catesbeiana, Nebraska, U. S. A. (personal collection Dr. Daniel R. Brooks). Scale bar = 0.3 mm. 3. Detail of the anterior end showing the peripharyngeal glands ex Rana neovolcanica, Michoacán, Mexico (CNHE 3272) Scale bar = 0.1 mm. 4. Mature specimen, ventral view ex Rana spectabilis, Oaxaca, Mexico (CNHE 4689). Scale bar = 0.3 mm. 5. Immature specimen ex Rana montezumae, Estado de Mexico, Mexico (CNHE 3275). Scale bar = 0.3 mm.

FIGURES 12 – 15. Glypthelmins intestinalis (Lucker, 1931) O´Grady, 1987. 12. Mature specimen, ventral view ex Rana luteiventris, Montana, U. S. A. (CNHE 4692). Scale bar = 0.3 mm. 13. Detail of the ventral sucker and suctorial disc showing 9 papillae, ex Rana luteiventris, Montana, U. S. A. (CNHE 4692). Scale bar = 0.05 mm. 14. Mature specimen, dorsal view ex Rana luteiventris, Montana, U. S. A. (CNHE 4692). Scale bar = 0.3 mm. 15. Detail of the terminal genitalia ex Rana luteiventris, Montana, U. S. A. (CNHE 4692). Scale bar = 0.1 mm.