Hyperolius Rapp 1842

Duszynski, Donald W., Bolek, Matthew G. & Upton, Steve J., 2007, Coccidia (Apicomplexa: Eimeriidae) of amphibians of the world, Zootaxa 1667 (1667), pp. 1-77 : 33-35

Host genus Hyperolius Rapp 1842

(125 spp.)

Eimeria wambaensis Jirků and Modrý 2005 ( Fig. 18) Type host: Hyperolius viridiflavus (Duméril & Bibron 1841) , Common reed frog.

Other hosts: None reported to date.

Type locality: AFRICA: Kenya, Wamba (Rift Valley province, 00° 56' 58.4" N, 37° 20' 56.9" E) .

Geographic distribution: AFRICA, Kenya.

Description of sporulated oocyst: Oocyst shape: ellipsoidal to ovoidal; number of walls: 2; outer, 0.5– 0.7, smooth; inner, 0.1–0.2; L x W: 17–13 (15–18.5 x 11–14); L/W ratio: 1.4 (1.2–1.6); M, OR, PG: all absent. Distinctive features of oocyst: wall tightly encloses the sporocysts such that they sometimes appear deformed.

Description of sporocyst and sporozoites: Sporocyst shape: navicular (slightly pointed at both ends); L x W: 8.7 x 6.0 (8–10.5 x 5.5–7); L/W ratio: 1.4 (1.2–1.6); SB: present, but barely visible as slight thickening at one end of sporocyst; SSB and PSB: absent; SR: present; SR characteristics: composed of coarse granules of irregular shape, each 1.5–2 wide, and these completely fill the sporocyst leaving only small parts of SZ visible; SZ: arranged head to tail, each with 1 spheroidal N visible, 1.5 wide, in center of SZ. Distinctive features of sporocyst: thin, single-layered wall and navicular shape.

Prevalence: 1 of 2 (50%) frogs from Wamba; 0 of 40 frogs from the Kakamega forest.

Sporulation: Exogenous.

Prepatent and patent periods: Unknown.

Site of infection: Intranuclear in epithelial cells of both small and large intestines.

Endogenous stages: All endogenous stages are surrounded by a PV and develop in the N of epithelial cells of the small and large intestine. Early trophozoites were 3.5 x 2–3, located within a vacuole insde the host cell N. Mature microgamonts were spheroidal to ellipsoidal, ~10–15 x 8–10. Microgamonts in various stages of development were 11–16 x 7–12 and contained a large N and numerous eosinophilic granules resembling wall-forming bodies. No meronts were observed.

Pathology: None described.

Materials deposited: Photosyntypes of sporulated oocysts and histological sections with (undescribed) endogenous stages deposited in the Department of Parasitology, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic (R 65/04). Symbiotype host (sensu Frey et al. 1992) in the herpetology collection of the National Museum of Kenya, Nairobi (A/4130).

Remarks: This is the first emerian described from this host genus. Its oocysts differ in both quantitative and qualitative features from all other known anuran eimeriids. Further, the geographic origin and host phylogeny make the conspecificity with other Eimeria spp. unlikely.

Goussia hyperolisi Paperna, Ogara and Schein 1997 ( Fig. 19)

Type host: Tadpole of Hyperolius viridiflavus (Duméril & Bibron 1841) , Common reed frog.

Other hosts: None reported to date.

Type locality: AFRICA: Kenya, Sagana fish ponds .

Geographic distribution: AFRICA, Kenya.

Description of sporulated oocyst: Oocyst shape: subspheroidal; number of walls: initially a typical plasma membrane (see Remarks, below), but as the oocyst matures this envelope seems to merge with the wall of the PV that surrounds it; wall characteristics: membranous; L x W: 7.7 (7–10) or 7–9 x 6–8; L/W ratio: 1.1– 1.3; M, OR, PG: all absent. Distinctive features of oocyst: the plasma membrane of the oocyst merges with the membrane of the PV and then becomes surrounded and enclosed by a yellow body, which may be an accumulation of degenerate intraepithelial lymphocytes resulting as part of a host defense process.

Description of sporocyst and sporozoites: Sporocyst shape: ellipsoidal (line drawing); L x W: 7.2 x 4.9 (6–8 x 4–6); L/W ratio: 1.5; SB, SSB, PSB: all absent; SR: present; SR characteristics: a ball of large granules/globules that gradually disintegrates and disappears once SZ differentiation is completed; SZ: 7 x 1.4–2, with a RB ~4.2–5.6 x 2.8. Distinctive features of sporocyst: a double-layered wall, 7.7–8.5 (?) thick, with distinct longitudinal sutures, characteristic of the genus, and a SR that disappears once the SZ differentiate.

Prevalence: 8 of 13 (61.5%) tadpoles, 0 of 4 (0%) post-metamorphosis, and 0 of 11 (0%) adult frogs.

Sporulation: Endogenous.

Prepatent and patent periods: Unknown.

Site of infection: Variable. Early developmental stages are found located in cells of the gut epithelium between the N and the brush border ( Paperna et al. 1997, p. 82), while the host cells of oocyst stages in the tadpoles resemble intraepithelial leuckocytes rather than ordinary mucosal epithelial cells ( Paperna et al. 1997, p. 87).

Endogenous stages: Early meronts were 4.5–5 x 2–4 and these later formed merozoites that the authors first said were 9.5 x 4 ( Paperna et al. 1997, p. 80), but later ( Paperna et al. 1997, p. 82) said were “very elongated,” 7–8 long. Young macrogamonts were 7–9 x 4–5 and contained within a PV. Microgamonts were not seen.

Pathology: Progressive cytoplasmic degradation of infected host cells that causes them to round up and separate from the surrounding host tissue.

Materials deposited: None.

Remarks: In addition to the discrepancy noted above, regarding length of the merozoites, there are a few other discrepancies by Paperna et al. (1997) that make our interpretation of some of their data tenuous. First, Paperna et al. (p. 85), stated that “early oocysts...were 7.7 (7.0–9.8) and sporoblasts 9.45 (8.4–10.6) in diameter.” Our view is that early oocysts and sporoblasts are one and the same. Second, early in their results they stated (p. 82), “Neither refractile nor crystalloid bodies could be identified in the newly formed sporozoites,” but later (p. 85) they said that SZs contained a RB, 4.2–5.6 x 2.8.

A number of Eimeria species described from anurans have very thin walled oocysts that undergo endogenous sporulation and some of these have sporocysts with longitudinal sutures rather than a SB. This led Molnár (1995) to place E. neglecta , which he redescribed, into the genus Goussia , of mostly piscine coccidian (see Steingagen 1991 and Steingagen & Körting 1990), but the members of which all share this unique sporocyst feature.

This is only the second eimeriid coccidium described from tadpoles; both are Goussia species and both seem to share some unique developmental features. Nöller (1920), who first described E. neglecta (= G. neglecta ), noticed the disappearance of infection from the tadpoles as they neared metamorphosis into frogs. Likewise, Paperna et al. (1997) found that the infections in H. viridiflavus also were found naturally only in tadpoles (8 of 13), but never in young post metamorphosis frogs (0 of 4) or in adult frogs (0 of 11). They also noted that infections terminated in tadpoles which failed to develop to the metamorphosis stage, suggesting to them that infection is time-restricted and expires independently of the metamorphosis process.

The sporulated oocysts of this species are similar in size to those of G. neglecta described from P. rhidibundus and P. esculenta tadpoles in Hungary. However, the sporocysts of this species are smaller (6.6 x 4.8) and have a smaller L/W ratio, 1.4, than those of G. neglecta , which are larger (8.8 x 4.8) with a larger L/W ratio, 1.8. This was the first coccidium described from anurans on the African continent.