Eimeria rioarribaensis Duszynski, Scott, Aragon, Leach, and Perry, 1999
Type host: Myotis ciliolabrum (Audubon and Bachman, 1942, Western small-footed myotis.
Other hosts: None reported to date.
Type locality: NORTH AMERICA: USA, New Mexico, Rio Arriba Co., Quintana Tank, 36º 35' N, 107º 23' W, elev. 2040 m.
Other localities: Mexico, Baja California Norte, 3.2 km NE of Rosarito.
Geographic distribution: NORTH AMERICA, USA, New Mexico; Mexico, Baja California Norte.
Description of oocyst:
Oocyst shape: subspheroidal;
number of walls: 2;
wall thickness: ~1.5;
wall characteristics: outer, yellowish, rough, ~2/3 of total thickness; inner dark, smooth;
L x W: 24.9 x 20.1 (18-27 x 17-23);
L/W ratio: 1.2 (1.1-1.3);
M: absent;
OR: absent;
PG: 1-2.
Distinctive features of oocyst: thick, rough outer wall.
Description of sporocysts and sporozoites:
Sporocyst shape: ellipsoidal;
L x W: 12.5 x 9.0 (8-14 x 7-10);
L/W ratio: 1.4 (1.2-1.5);
SB: present, ~1.5 wide;
SSB: present, ~2-3 wide;
PSB: absent;
SR: present;
SR characteristics: 8-10 globules often dispersed along edge of sporocyst;
SP: with an elongate RB in posterior half.
Distinctive features of sporocyst: SSB twice as wide as SB.
Prevalence: 4/22 (18%) in New Mexico; 1/21 (5%) in Mexico.
Sporulation: Presumably exogenous. Oocysts sporulated in 2% aqueous (w/v) potassium dichromate solution in the field.
Prepatent and patent periods: Unknown.
Site of infection: Unknown. Oocysts recovered from feces.
Materials deposited: Symbiotype host in the Museuwm of SW Biology, UNM: NK 27915, 13 June 1995. Photosyntypes of sporulated oocysts in the USNPC No. 88107.
Remarks: Structurally, sporulated oocysts of E. rioarribaensis are most similar to those of E. macyi in that they both have a rough outer wall, SB and SSB, and PG, and both lack an OR. They differ, however, in that E. rioarribaensis is larger (25 x 20 vs 19 x 18) with a 2-layered wall (vs 1) which is thicker (1.5 vs 1). This species differs from some other similar Eimeria spp. from Myotis in that E. catronensis is ellipsoidal and smaller and has a M; E. pilarensis and E. kunmingensis are both smaller (15 x 15 and 17.5 x 16, respectively) and both have have smooth outer oocyst walls; and E. californicensis and E. humboldtensis lack a SSB.
References: Duszynski et al. (1999; Scott and Duszynski (1997).