A review of the trypanosomes from lizards of the family Iguanidae (sensu lato), including the descriptions of five new species, and an evaluation of the effect of host difference upon taxonomic characters of saurian trypanosomes

Abstract

Five new species of Trypanosoma are described from iguanid lizards. In Texas, T. poinsetti n. sp. occurs in Sceloporus poinsetti and T. urosauri n. sp. in Urosaurus graciosus. Average dimensions of T. poinsetti are body length (BL) 35.7 × maximum width (MW) 10.7 µm, nucleus length (NL) 4.3 µm, position of kinetoplast (K%) 70.6, position of nucleus (N%) 61.9, ratio of BL: MW (SI) 3.4, and ratio (NI) of NL to nucleus width (NW) 1.5. In T. urosauri average dimensions are BL 34.3 × MW 6.3 µm, NL 2.4 µm, K% 57.5, N% 66.2, SI 5.6, and NI 1.3. Trypanosomes with small compact nuclei that parasitise four Anolis species from Belize to Panama are assigned to T. anolisi n. sp. Average dimensions from the type sample in Anolis limifrons of Panama are BL 24.6 × MW 17.9 µm, NL 2.1 µm, K% 82.0, N% 78.4, SI 1.6 and NI 1.1. T. fairchildi n. sp., from Anolis capito of Panama, is a large, tongue- or leaf-shaped flagellate with BL 49.2 × MW 28.8 µm, NL 2.0 µm, K% 75.6, N% 64.5, NL 2.0, SI 1.9 and NI 1.6. Dimensions of T. plicaplicae n. sp., from Plica plica of Guyana, average BL 30.9 × MW 19.9 µm, NL 7.2 µm, K% 75.8, N% 56.2, SI 1.6 and NI 2.3. In the United States, T. scelopori parasitises Sceloporus occidentalis and Crotaphytus collaris in California. Trypanosomes with an elongate slender nucleus found in lizards of the genera Sceloporus and Corytophanes from Veracruz, Mexico to Panama, and in Anolis probably as far as Peru, are all considered to be T. serveti. Other species may be present, but cannot be separated on the basis of consistent morphometric characters. Two additional species are known from endemic South American saurian genera: T. plicae occurs in Plica umbra and T. superciliosae in Uranoscodon superciliosa of Brazil. T. domerguei is known from the Madagascan iguanid, Oplurus sebae. Only T. scincorum of southeast Asian skinks lacks host effect upon morphological characters throughout its range. Samples from two hosts each of T. anolisi in Panama and T. uluguruense in Tanzania differed in only two of 10 characters analysed, suggesting little host effect. Other comparisons of iguanid and gekkonid trypanosomes suggested that differences in parasite strain rather than host might contribute to observed variation.