Conformational studies for the presence of coccidian parasites on white spotted gecko Tarentola annularis (Chordata: Gekkonidae)

The white spotted gecko Tarentola annularis (Family Gekkonidae) is a reptilian species found in the Middle East, Africa, and some states in the United States mainly Florida. A total of 40 specimens of this species were collected during the period of February –November 2016 from Abu-Rawash, Giza Governorate, Egypt; they were dissected and examined for the presence of parasitic infection. Only 35 (87.50%) specimens were found to be naturally infected with coccidian parasites. Seasonally, the prevalence of infection was reached its maximum value of 80.0% during summer and minimum value of 50.0%, 40.0%, 20.0% during spring, autumn, and winter, respectively. Prevalence and mean intensity of parasitic infection were negatively correlated with the host size as smaller geckos (<5cm in length and <30gm in weight) are more infected than larger ones (5-10 cm in length and >60gm in weight). The numbers of parasites of male and female T.annularis were compared, and no significant differences were observed. Morphology of the recovered parasites was studied by using light microscopy and revealed the presence of two new coccidian species identified as Eimeria tarentoli and Eimeria ghaffari belonged to the family Eimeriidae. Oocysts of Eimeria tarentoli n. sp. were spherical to sub-spherical with single-layered, measured 21.6-31.4 x 15.3-25.2 (26.5 x 19.2) µm, with shape-index (length/width) was 2.01 (1.58-2.34). Both micropyle and oocyst residuum were absent, but a fragmented polar granules were present. Oocysts of Eimeria ghaffari n. sp. were elongated to cylindroids with single-layered wall, measured 29.6-31.3 x 14.7-23.2 (34.5 x 19.3) µm, shape-index (length/width) was 2.01 (1.98-2.65). Micropyle and oocyst residuums were absent, but single polar granule was present. Combining morphological characteristics, host specificity and geographical distribution, tissue tropism, in addition to molecular analysis of partial sequence of SSU ribosomal DNA gene, revealed that the recovered parasite species described herein were genetically distinct from other coccidian species, but had 95.7-95.1% sequence similarity to E. collieie and E. arnyi. Also, Phylogenetic analysis placed the present coccidian species in the gekkonid Eimeria clade, which is a sister group of bovids Eimeria species. In addition, the present study was considered as the first report for occurrence of eimerian species from the white spotted gecko in Egypt.