Isospora motleiensis Ford and Duszynski, 1988

Type host: Scalopus aquaticus (Linnaeus, 1758), Eastern AMerican mole.

Other hosts: None reported to date.

Type locality: NORTH AMERICA: USA, Texas, Motley Co.

Geographic distribution: NORTH AMERICA: USA, Texas.

Description of oocyst: Oocyst shape: spheroid to subspheroid; number of walls: 2; wall thickness: <1.0; wall characteristics: both layers smooth, of equal thickness; L x W: 13.6 x 12.0 (10-17 x 8-15); L/W ratio: 1.1 (1.0-1.8); M: absent; OR: absent; PG: 1. Distinctive features of oocyst: smooth, thin wall with 1 prominent PG.

Description of sporocysts and sporozoites: Sporocyst shape: broadly ovoid; L x W: 9.5 x 6.7 (7-11 x 4-8); L/W ratio: 1.4 (1.0-1.8); SB: present, small; SSB: absent; PSB: absent; SR: present; SR characteristics: composed of 7 or more globules clumped in the middle of sporocyst; SP: with 1 posterior and 1 mid RB, although this was not mentioned in the original description. Distinctive features of sporocyst: SR of clumped globules and SP with 2 RB.

Prevalence: 9/13 (69%).

Sporulation: Exogenous. Oocysts sporulated in 7-10 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: Skin, skull, skeleton and tissues of the symbiotype host are preserved in the Mammal Division of the Museum of SW Biology, UNM: MSB No. 46331 (NK 4860, female), R.M. Sullivan #622, 14 March, 1981. Photosyntypes in the USNPC No. 85992.

Remarks: Oocysts of this species resemble those of I. neurotrichi Duszynski, 1985 and I. urotrichi Duszynski and Moore, 1986). They differ from those of the former by having only 2 layers in the oocyst wall (<1.0), whereas I. neurotrichi has 3 layers (>1.0) when seen with transmitted light. They differ from those of the latter only by having a smooth outer oocyst wall, whereas those of I. urotrichi is lightly mammillated. The only other structural difference between these Isospora spp. is both I. neurotrichi and I. urotrichi have multiple PGs, whereas those of I. motleiensis always have only 1 PG. Although structurally similar, their hosts are unrelated and the ranges of their hosts do not overlap. Both I. neurotrichi and I. urotrichi are found in shrew moles; the former infects N. gibbsii, which occurs only in the northwestern USA, and the latter infects U. talpoides, found on the islands of Japan.

References: Ford and Duszynski (1988).