Lithobates Fitzinger 1843

Duszynski, Donald W., Bolek, Matthew G. & Upton, Steve J., 2007, Coccidia (Apicomplexa: Eimeriidae) of amphibians of the world, Zootaxa 1667 (1667), pp. 1-77 : 37-39

Host genus Lithobates Fitzinger 1843

(49 spp.)

Eimeria algonquini Chen and Desser 1989 ( Fig. 22)

Type host: Lithobates catesbeianus (Shaw 1802) , American bullfrog.

Other hosts: Lithobates clamitans (Latreille In Sonnini de Manoncourt and Latreille 1801) , Green frog; Lithobates septentrionalis (Baird 1854) , Mink frog; Lithobates sylvaticus (LeConte 1825) , Wood frog.

Type locality: NORTH AMERICA: Canada, Ontario, Algonquin Park, Lake Sasajewun .

Geographic distribution: NORTH AMERICA: Canada, Ontario.

Description of sporulated oocyst: Oocyst shape: spheroidal; number of walls: 1; wall thickness: thin; wall characteristics: smooth; L x W: 15.8 (14.5–16); L/W ratio: 1.0; M and PG: absent; OR: present; OR characteristics: spheroidal, 10 (9–11), composed of coarse granules. Distinctive features of oocyst: colorless, thin, smooth wall and the massive size of the OR which mostly obscures the sporocysts (line drawing).

Description of sporocyst and sporozoites: Sporocyst shape: banana-shaped; L x W: 19.5 x 4.2 (19–20 x 4–5); L/W ratio: 4.6; SB, SSB, PSB: all absent; SR: present; SR characteristics: composed of small, coarse granules (line drawing); SZ: elongate, 13.8 x 1.6 (13.5–14 x 1–2), 2 spheroid RBs present, located one on each side of an indistinct N. Distinctive features of sporocyst: very thin wall that is almost invisible (line drawing) and a L/W ratio that is the largest of any amphibian coccidium.

Prevalence: 26 of 162 (16%) Lithobates catesbeianus ; 3 of 25 (12%) Lithobates clamitans ; 7 of 68 (10%) Lithobates septentrionalis ; 3 of 9 (33%) Lithobates sylvaticus .

Sporulation: Presumably endogenous.

Prepatent and patent periods: Unknown.

Site of infection: Unknown (see Remarks).

Endogenous stages: Unknown.

Pathology: None observed, to date.

Materials deposited: None.

Remarks: There are four other species of amphibian Eimeria that have spheroidal oocysts similar to those of E. algonquini . Sporulated oocysts of E. belawini ( Fig. 10), E. laminata ( Fig. 5), and E. mazzai ( Fig. 1) are smaller, while those of E. streckeri ( Figs. 13, 14, 55, 56) are larger than those of E. algonguini . In addition, sporocyst sizes, hosts and geographical locations are different between these five species.

The authors suggested that due to the method of obtaining fecal samples (gently squeezing the abdomen or giving the frog an enema with 85% saline), only moderate to heavy infections were detected, while lighter infections may have been missed. Thus, actual prevalence in examined frogs may have been higher than what they found. Young bullfrogs, based on size, were most frequently infected. This might be due to sporulated oocysts released into the water being ingested by larger invertebrates and, or, tadpoles, the prey of young bullfrogs ( Korschgen & Baskett 1963; Fulk & Whitaker 1969). Chen and Desser (1989) reported the site of infection for E. algonquini as the intestine, but oocysts were recovered from the feces and no attempt was made to examine the intestine for developing stages of E. algonquini ; therefore, the site of infection for this species is unknown.

Eimeria fitchi McAllister, Upton, Trauth and Bursey 1995 ( Figs. 23, 60)

Type host: Lithobates sylvaticus (LeConte 1825) , Wood frog.

Other hosts: None reported to date.

Type locality: NORTH AMERICA, USA, Arkansas, Izard County, 6.0 km SW of Melbourn, off State Highway 9 .

Geographic distribution: NORTH AMERICA, USA, Arkansas.

Description of sporulated oocyst: Oocyst shape: ovoidal; number of walls: 1; wall thickness: 0.5; wall characteristics: smooth; L x W: 21.9 x 14.3 (20–24 x 13–15); L/W ratio: 1.5 (1.3–1.7); M and OR: absent; PG: usually absent, but sometimes 1–3 fragments are attached to the outer wall of the sporocysts. Distinctive features of oocyst: very thin wall and fragments of debris (former PG?) attached to outer wall of sporocysts.

Description of sporocyst and sporozoites: Sporocyst shape: ovoidal; L x W: 10.9 x 7.4 (10–11 x 7–8); L/W ratio: 1.5 (1.3–1.6); SB: present (?) as a slight thickening at one end of sporocyst; SSB and PSB: absent; SR: present; SR characteristics: 3.6 x 1.6, consisting of ~25 large, coarse, scattered granules; SZ: elongate, 11.1 x 1.7 (10–12 x ~2) in situ, with 2 RBs, 1 an anterio-central, spheroidal, ~1.1 wide, and a posterior RB, subspheroidal to ovoidal, 2.9 x 1.6 (2–3 x 1.4–1.6); an indistinct N lies between the 2 RBs, 1 anterio-central, spheroidal, ~1.1 wide, and a posterior RB, subspheroidal to ovoidal, 2.9 x 1.6 (2–3 x 1.4–1.6); an indistinct N Lies between the 2 RBs. Distinctive features of sporocyst: none.

Prevalence: 11 of 13 (85%).

Sporulation: Exogenous, complete within 5 days at 23° C.

Prepatent and patent periods: Unknown.

Site of infection: Unknown, oocysts recovered from rectal contents.

Endogenous stages: Unknown.

Pathology: None observed to date.

Material deposited: Photosyntype of sporulated oocysts in USNPC (No. 84163). Symbiotype host deposited at ASUMZ (Cat. No. 19434).

Remarks: The host frogs and their oocysts were collected in February, 1994; this was the first ranid frog in the United States documented to harbor coccidia. This species can be easily distinguished from E. kermiti and E. algonquini described from L. sylvaticus in Ontario, Canada. Sporulated oocysts of E. kermiti ( Fig. 24) are larger and have an OR and PG, and sporocysts with a distinct SB while those of E. algonquini ( Fig. 22) are spheroidal, with very thin-walled sporocysts.

Eimeria kermiti Chen and Desser 1988 ( Fig. 24)

Type host: Lithobates catesbeianus (Shaw 1802) , American bullfrog.

Other hosts: Lithobates clamitans (Latreille In Sonnini de Manoncourt and Latreille 1801) , Green frog; Lithobates septentrionalis (Baird 1854) , Mink frog; Lithobates sylvaticus (LeConte 1825) , Wood frog.

Type locality: NORTH AMERICA: Canada, Ontario, Algonquin Park, Pee Wee Lake .

Geographic distribution: NORTH AMERICA: Canada, Ontario.

Description of sporulated oocyst: Oocyst shape: ovoidal; number of walls: 1; wall thickness: “thin;” wall characteristics: smooth; L x W: 25.1 x 19.5 (25–27 x 18–20); L/W ratio: 1.3; M: absent; OR: present; OR characteristics: spheroidal to subspheroidal, 8.3 x 7.3 (8–9 x 7–7.5), composed of a large vacuole surrounded by coarse granules; PG: present. Distinctive features of oocyst: very thin, single-layered wall.

Description of sporocyst and sporozoites: Sporocyst shape: ovoidal; L x W: 9.9 x 6.6 (9–10 x 6–7); L/ W ratio: 1.5; SB: present as a small, nipple-like structure at one end of sporocyst; SSB and PSB: absent; SR: present; SR characteristics: spheroidal to subspheroidal body, 3.3 x 2.4 (4–5 x 2–3), composed of coarse granules between SZ; SZ: elongate, 8.6 x 2.3 (8–9 x 2–3), indistinct N lies between 2 small RBs. Distinctive features of sporocyst: none.

Prevalence: 3 of 162 (2%) Lithobates catesbeianus ; 1 of 25 (4%) Lithobates clamitans ; 1 of 68 (2%) Lithobates septentrionalis ; 1 of 9 (11%) Lithobates sylvaticus .

Sporulation: Presumably endogenous.

Prepatent and patent periods: Unknown.

Site of infection: Unknown (see Remarks).

Endogenous stages: Unknown.

Pathology: None observed.

Materials deposited: None.

Remarks: This species is distinguished from E. ranarum ( Fig. 26) by its larger oocysts (25 x 19.5 vs. 18– 20 x 12–16) as well as from those of E. leptodactyli (23 x 17, Fig. 20). The authors suggest that due to the method of obtaining fecal samples (gently squeezing the abdomen or giving the frog an enema with 85% saline) only moderate to heavy infections were detected, while lighter infections may have been missed. Thus, the prevalences in the frogs they examined may be higher than what they reported. Young bullfrogs, based on host size, were most frequently infected. This might be due to sporulated oocysts that are released into the water being ingested by larger invertebrates and tadpoles, the prey of young bullfrogs ( Korschgen & Baskett 1963; Fulk & Whitaker 1969). Chen and Desser (1989) reported the site of infection for E. kermiti as the intestine, but oocysts were recovered from the feces and no attempt was made to examine the intestine for developing stages of E. kermiti ; thus, the site of infection for this species is unknown.