Phylogeny of Palaearctic Pharyngodonidae parasite species of Testudinidae: a morphological approach

Abstract

The phylogenetic relationships of 23 oxyurid species from five genera (21 parasite species of the Palaearctic Testudinidae, 1 parasite species of Uromastix acanthinurus Bell, 1825 from Algeria, and 1 parasite species of Cteno sa ura pectinata (Wiegmann, 1834) from Mexico) were investigated using 30 morphological characters obtained from species descriptions. The nonweighted analysis produced one shortest tree. All species of the ingroup form a monophyletic group and the oxyurid species of Testudinidae form a monophyletic group. The type species of the genus Alaeuris Thapar, 1925 is the basal member of the species parasitizing Testudinidae. The analysis confirms the monophyly of the genus Thaparia Ortlepp, 1933, whereas the genera Mehdiella Seurat, 1918 and Tachygonetria Wedl, 1862 are considered paraphyletic groups. The large diversification in the genus Tachygonetria is linked to their position in the host caecum. The ancestral state is in the paramucous and the derived state is in the centre of the caecum. This suggests that recent speciation in the group occurs in the centre of the caecum.