Phylogenetic and molecular analysis of a new species of Isospora Schneider, 1881 (Apicomplexa: Eimeriidae) of the blue mockingbird Melanotis caerulescens (Swainson) (Passeriformes: Mimidae) in the Protected Natural Area, Morelia, Michoacán, Mexico.

A new coccidian species, Isospora melanotidis n. sp. from the blue mockingbird Melanotis caerulescens (Swainson), from Morelia, Michoacán State, Mexico. It is described and characterized molecularly. Sporulated oöcyst of the new species are subspherical, 25‒29 × 21‒25 (26.9 × 23.1) µm, (n = 30), with a length/width (L/W) ratio 1.0‒1.1 (1.04). Wall bi-layered 0.6‒1.1 (0.8) thick, clear outer and dark interior. One polar granule present, but micropyle and oöcyst residuum are absent, Sporocysts are ovoidal, measuring on average 14‒22 × 10‒13 (16.6 × 10‒13) µm, with a L/W ratio of 1.5; Stieda, sub-Stieda and para-Stieda bodies are present. A sporocyst residuum is present as a diffuse mass of granules. The 18S rRNA gene loci segment of Isospora sp., used for phylogenetic analysis by means of a maximum likelihood (ML) tree, revealed that Isospora sp., from M. caerulescens is distinct from Isospora sp., from Bewick's Wren Thryomanes bewickii, with node support and bootstrap length of 91.5%. To date, this is the third report on Isospora Schneider 1881 (Apicomplexa: Eimeriidae), which infects Passeriformes of the Mimidae family of the Americas.