Eimeria chagasi Yakimoff and Gousseff, 1935

Type host: Sorex araneus Linnaeus, 1758, Eurasian common (Gomel) shrew.

Synonyms: Eimeria komareki Cerna and Daniel, 1956; Eimeria komareki of Arnastauskiene and Maldziunaite, 1979; E. komareki of Arnastauskiene, 1980.

Other hosts: Sorex arcticus Kerr, 1792, Arctic shrew; Sorex minutus Linnaeus, 1766, Pygmy shrew.
Type locality: ASIA: Russia, Gomel District.

Geographic distribution: EUROPE: Bulgaria,; Czechoslovakia; ASIA: Russia.

Description of oocyst: Oocyst shape: spheroid to slightly subspheroid ; number of walls: 1; wall thickness: ~1.0; wall characteristics: smooth colorless; L x W: 14.5 (13-19 x 12-15); L/W ratio: 1.0-1.1; M: absent; OR: absent; PG: 1; Distinctive features of oocyst: small, spheroid size and shape without OR

Description of sporocysts and sporozoites: Sporocyst shape: ellipsoid; L x W: 8-9 x 4-5; SB: absent; SSB: absent; PSB: absent; SR: present; SR characteristics: a mass of small granules in center of sporocyst between the SP; SP: sausage-shaped without a RB. Distinctive features of sporocyst: nondescript, without a SB.

Prevalence: 1/26 (4%) from the type host; 1/17 (6%) in Bulgaria.

Sporulation: Exogenous. Oocysts sporulated in 1-2 days in 1.5% aqueous (w/v) potassium "bichromate" solution.

Prepatent and patent periods: Unknown.

Site of infection: Oocysts in original description recovered from feces and intestinal contents, but gamogony, according to Cerna (1961) occurs in the small intestine.

Materials deposited: None.

Remarks: Very little information on oocyst structure was given in the original description. Yakimoff and Gousseff (1935) described the oocysts as spheroid, 14.5 in diameter, without an OR, but with a PG and they did provide a line drawing. Cerna and Daniel (1956) described similar oocysts from S. araneus, but called it E. komarki. Both descriptions are incomplete by any measure, but their descriptions and respective line drawings are virtually identical; thus they are probably the same species. Cerna (1961) described the micro- and macrogamonts (which she stilled called E. komareki) from S. araneus collected from Sarka near Prague, Czechoslovakia. Thus, the preceding information given is a synthesis from these three papers. Cerna also said she saw E. komareki in Neomys fodiens, but Golemansky (1978) named the form Cerna saw as E. neomyi. In the same paper, Golemansky (1978) described E. ropotamae from Crocidura leucodon; the description he gave shows only a small size difference between the sporulated oocysts of E. neomyi and E. ropotomae and his drawings of both are indistinguishable. It is possible that the difference in oocyst size may be attributed to the variability in host species discussed by Reduker et al.(1985) or to inherent individual variability in oocysts size over patency (Duszynski, 1971), or both. If true, E. komareki, E. neomyi, and E. ropotomae may all be synonyms of E. chagasi. Additional studies are needed to determine if this is the case.

References: Yakimoff and Gousseff (1935); Cerna and Daniel (1956); Cerna (1961); Golemansky and Yankova (1973); Arnastauskiene and Maldziunaite (1979); Golemansky (1979); Arnastauskiene (1980).