Isospora pityli McQuistion &
Type host: Pitylus grossus
saturates (Slate-colored grosbeak)
Type locality: SOUTH AMERICA:
Ecuador, Provincia de Esmeraldas, ca. 20 km NW of ALto Tambo,
elev. 275 m.
Geographic distribution: SOUTH
Description of oocyst: Oocyst shape:
spheroid to subspheroid; number of walls: 2; wall thickness: ~1.5; wall
characteristics: smooth, colorless outer surface with darker, thinner
inner layer; L x W: 20.1 x 18.8 (17-20 x 20-21); L/W ratio: 1.1 (1.0-1.2);
M: absent; OR: absent; PG: absent. Distinctive features of oocyst: lack of
M, OR, and PG.
Description of sporocysts and
sporozoites: Sporocyst shape: ovoid; L x W: 14.7 x 9.4 (8-11 x
12-17); L/W ratio: 1.6 (1.3-1.7); SB: present as small, nipple-like
body; SSB: absent; PSB: absent; SR: present; SR
characteristics: amorphous cluster of coarse, nonuniform granules, ~4-5
in diameter; SP: large and elongate with large RB, 4 x 5, at 1 end and
lying side by side. Distinctive features of sporocyst:
SP and SR appear to be enclosed in a thin membrane
Prevalence: 1 of 1 (100%).
Sporulation: Exogenous. Oocysts were
stored in 2.5% (w/v) aqueous potassium dichromate solution at
ambient temp. prior to examination.
Prepatent and patent periods:
Site of infection: Unknown.
Oocysts found in feces.
Materials deposited: None.
Remarks: This species has not been
reported since its original description.
Reference: McQuistion & Capparella