Eimeria whitakeri Upton and McAllister, 1991
Type host: Cryptotis parva parva (Say, 1823), Least shrew.
Other hosts: None reported to date.
Type locality: NORTH AMERICA: USA, Texas, Johnson County.
Geographic distribution: NORTH AMERICA: USA, Texas.
Description of oocyst: Oocyst shape: spheroid to subspheroid;
number of walls: 2;
wall thickness: 1.2;
wall characteristics: outer, smooth to lighly pitted, ~2/3 of total thickness;
L x W: 17.4 x 16.4 (15-19 x 13-18.5);
L/W ratio: 1.1 (1.0-1.2);
PG: 1, rather large and highly refractile.
Distinctive features of oocyst: large, highly refractile PG.
Description of sporocysts and sporozoites:
Sporocyst shape: ovoid;
L x W: 11.2 x 7.5 (9.5-12 x 6.5-8), with a smooth, thin, single-layered wall ~0.4;
L/W ratio: 1.5 (1.4-1.6);
SB: present as thickened end of the sporocyst;
SSB: present, convex, twice as wide as SB;
SR characteristics: cluster of globules, 6.7 x 3.6 (5.5-8 x 2-5.5), either between SP of pressed tightly
against sporocyst wall;
SP: elongate, 13.6 c 3.2 (12-16 x 3-3.5), arranged head-to-tail, each with a spherical anterior
refractile body 2.2 (2-2.5) and ellipsoidal posterior refractile body 5.6 x 3.0 (4-6.5 x 2.5-3.5) and
a centrally located N between RBs.
Distinctive features of sporocyst: combination of convex SSB, SR, and SP with 2 RB.
Prevalence: 2/9 (22%) from Johnson County, but 0/1 from Denton County, 0/4 from
Dallas County, and 0/5 from Hood County.
Sporulation: Exogenous. Oocysts sporulated in 7 days in 2.5% aqueous (w/v) potassium
dichromate solution at ~23 C .
Prepatent and patent periods: Unknown.
Site of infection: Unknown. Oocysts recovered from feces and intestinal contents.
Materials deposited: Symbiotype host was not preserved, but syntypes (oocysts in 10% neutral
buffered formalin) were deposited in the USNPC, No. 81476.
Remarks: This is only the second Eimeria species described
from Cryptotis. Its oocysts differ from those of E. cryptotis by being slightly smaller, as are the
sporocysts, by having a larger SR, and by having SP with RBs; this species has not been reported since its
References: Upton and McALlister (1991)