Isospora cebi Marinkelle, 1969.

Type host: Cebus albifrons (Humboldt, 1812), White-fronted capuchin.

Other hosts: None reported to date.

Type Locality: SOUTH AMERICA: Colombia, Alto Magdalena region.

Geographic Distribution: SOUTH AMERICA: Colombia, Alto Magdalena region.

Description of oocyst: Oocyst shape: subspheroid; number of walls: 1 (confirmed by crushing oocyst); wall thickness: 0.4-0.7; wall characteristics: colorless and smooth; L x W: 20.9 x 19.8 (19-23 x 16.5-21); L/W ratio: 1.1; M: absent; OR: absent; PG: absent. Distinctive features of oocyst: thin, 1-layered wall.

Description of sporocysts and sporozoites: Sporocyst shape: slightly ovoid; L x W: 14.9 x 11.2 (12-17 x 9-14); L/W ratio: 1.3; SB: present; SB characteristics: small, but pronounced; SSB: absent; PSB: absent; SR: present; SR characteristics: compact, round, granular, relatively small; SP: reniform, fill ~ 3/4 of the sporocyst. Distinctive features of the sporocyst: very thin wall, 0.2-0.4, and small, but distinct SB; also, SP do not fill the sporocyst as in most species. One of only 2 primate Isospora with a SB.

Prevalence: 1/4 (25%) C. albifrons from the Magdalena region, but 0/2 from the Antioquia region and 0/6 from unknown localities of Colombia.

Sporulation: Exogenous. Sixty percent of the oocysts sporulated in 3 days at 25ºC.

Prepatent and patent periods: Unknown.

Site of infection: Unknown. Oocysts recovered from feces.

Material deposited: None.

Remarks: Marinkelle (1969) also measured unsporulated oocysts which were slightly smaller than sporulated oocysts: 20.1 x 18.8 (18-22 x 16-20). This species has not been reported since Marinkelle's original report (1969). Because the sporocysts of this species possess SBs, Lindsay et al. (1997) believe it is a pseudoparasite of the capuchin, probably of bird origin, just passing through the intestinal tract, but there is no way to dispute or verify this idea given the available evidence.

References: Lindsay et al. (1997); Marinkelle (1969).