Two new species of coccidia (Apicomplexa: Eimeriidae) from ground skinks, Scincella lateralis (Sauria: Scincidae), from Arkansas, USA.

Between February 2011 and January 2014, 75 ground skinks, Scincella lateralis (Say) were collected from 13 counties of Arkansas and McCurtain County, Oklahoma, USA, and examined for coccidia. Two (3%) and 11 (15%) S. lateralis were found to be passing oöcysts of a new choleoeimerian and isosporan, respectively. Oöcysts of Choleoeimeria ouachitensis n. sp. are ellipsoidal to cylindroidal with a smooth, colourless, bi-layered wall and measure 27.2 × 15.6 μm, and have a length/width (L/W) ratio of 1.7; both micropyle and oöcyst residuum are absent, but 1-2 polar granule(s) are present. Sporocysts are ovoidal, 8.9 × 6.8 μm, L/W 1.3; neither Stieda, sub-Stieda and para-Stieda bodies are present; the walls have two valves joined by longitudinal sutures; a sporocyst residuum consisted of dispersed granules between sporozoites. Oöcysts of Isospora koberi n. sp. are ovoidal with a smooth, colourless, bi-layered wall and measure 25.1 × 20.5 μm, L/W 1.2; both micropyle and oöcyst residuum are absent, but a polar granule is rarely present. Sporocysts are ovoidal, 11.4 × 8.6 μm, L/W 1.3; a nipple-like Stieda body and a sub-Stieda body are present without a para-Stieda body; a sporocyst residuum consisted of condensed granules dispersed between sporozoites. This is the second choleoeimerian and third isosporan reported from S. lateralis.