Taxonomy of trypanosomes (Protozoa: Trypanosomatidae) of Spermophilus spp. (Rodentia: Sciuridae).

Trypanosoma spp. of ground squirrels and most other rodents belong to the 3ubgenus Herpetosoma and have been recorded from approximately 80 to 90 different species of rodents throughout the world (Davis, 1952). They are often designated as leurisi-like after the type species, Trypanosoma (Herpetosoma) lewisi (Kent) Laveran & Mesnil. All are very similar in appearance and cannot be differentiated with certainty by morphological differences alone since there is great variation in body size even within a single host animal (Davis, 1952). Thus, most investigators have described as new any trypanosome found in the blood of a different host species. Trypanosomes have been named from eight species of Spermophilus (= Gitellus) four in the U.S.S.R. and four in North America. Although Galuzo & Novinskaya (1968) list nine species of Russian ground squirrels as hosts for trypanosomes, many of their host species are, as Ellerman & Morrison-Scott (1951) and Ognev (1963) show, subspecies of more generally accepted species. According to Galuzo & Novinskaya (1968) trypanosomes from Russian ground squirrels were first observed by ShalashnikovJ in 1888 from 8. pygmaeus musicus Menetries and 8. suslica guttatus Pallas. In 1910, GrjunerJ reported trypanosomes from 8. undulatus eversmanni Brant collected at Yakutia. Laveran (1911) then gave the name Trypanosoma spermophili to the trypanosomes from these three species of hosts. In 1913 TartakovskyJ described T. schalaschnicovi from 8. suslica guttatus obtained near Kherson. Kol'tzovf (1914) recorded trypanosomes from 8. pygmaeus mugozaricus Lichtenstein and S. f. fulvus Lichtenstein caught near Ural'sk, as did NikitinJ (1927) from S. s. suslica Giildenstaedt obtained at Odessa. Neither of these investigators named the trypanosomes. Bozhenko (1927) found trypanosomes in 8. f. fulvus, 8. pygmaeus mugozaricus, S. pygmaeus musicus, and 8. s. suslica trapped in the area between the Urals and the Volga River. On the basis of successful cross-transmission experiments he regarded all four strains as T. spermophili. Bozhenko was unable to infect 'white mice, guinea-pigs, hares, skunks, grey rats, dogs, cats, and camels'. ZasukhinJ (1936) observed trypano-