Plethodon Tschudi 1838

Duszynski, Donald W., Bolek, Matthew G. & Upton, Steve J., 2007, Coccidia (Apicomplexa: Eimeriidae) of amphibians of the world, Zootaxa 1667 (1667), pp. 1-77 : 52-53

Host genus Plethodon Tschudi 1838

(55 spp.)

Isospora hightoni Upton, McAllister and Trauth 1993 ( Figs. 40, 65)

Synonym: Isospora sp. of McAllister, Upton and Trauth 1993.

Type host: Plethodon albagula Grobman 1944 , Western slimy salamander.

Other hosts: None reported to date.

Type locality: NORTH AMERICA: USA, Arkansas, Grant County, 6.4 km SW

Sheridan.

Geographic distribution: NORTH AMERICA: USA, Arkansas.

Description of sporulated oocyst: Oocyst shape: spheroidal, rarely subspheroidal; wall thickness: ~1; wall characteristics: 2 layers, outer, smooth, ~1/2 of total thickness; L x W: 22.9 x 22.8 (21–24 x 21–24); L/W ratio: 1.0 (1.0–1.0+); M, PG: absent; OR: present; OR characteristics: a mass of small granules surrounding a central globule, all enclosed in a thin membrane, ~2.5–5 wide, but present in only 33% of the oocysts. Distinctive features of oocyst: unique OR that is present in only about 1/3 of the oocysts.

Description of sporocyst and sporozoites: Sporocyst shape: ovoidal, slightly pointed at one end; L x W: 16.6 x 11.1 (14.5–17.5 x 10.5–14); L/W ratio 1.5 (1.4–1.6); SB: present as large knob at pointed end, 1.2–1.6 high x 2–2.5 wide; SSB: present, 1.5–2.5 high x 2.5–3 wide; PSB: absent; SR: present; SR characteristics: composed of numerous coarse globules scattered among SZ; SZ: elongate sausage-shaped, 13.6 x 2.7 (12– 14.5 x 2.5–3) each with 2 RB; anterior RB subspheroidal to ellipsoidal, 2.7 x 2.5 (2.5–3 x 2–3) and posterior RB smaller, spheroidal to subspheroidal, 2.3 x 2.2 (2–3 x 2–2.5); N located between refractile bodies. Distinctive features of sporocyst: large, distinct SB and SSB.

Prevalence: 8 of 46 (17%).

Sporulation: Exogenous, all oocysts were passed unsporulated and became fully sporulated within 1 wk at ~23° C.

Prepatent and patent periods: Unknown.

Site of infection: Unknown, oocysts recovered from feces and intestinal contents.

Endogenous stages: Unknown.

Pathology: Unknown.

Material deposited: Photosyntypes deposited in the USNPC (No. 83260). Symbiotype host (sensu Frey et al. 1992) a juvenile male, 25 mm snout-vent length, collected 20 March, 1992, deposited in the ASUMZ (Cat. No. 18277).

Remarks: The only other isosporan described from caudate amphibians is I. jeffersonianum ( Fig. 39) from the blue-spotted salamander A. laterale (= A. jeffersonianum ) from Minnesota. The latter possesses a knob or thickening in the oocyst wall that I. hightoni lacks and the sporocysts of I. jeffersonianum are more elongate than those of I. hightoni .