The Coccidia (Apicomplexa) of the Archosauria (Crocodylia: Eusuchia) of the World.

Abstract

The order Crocodylia (suborder Eusuchia) includes 27 species of alligators, caimans, crocodiles, and gharials that are cosmopolitan in distribution, inhabiting subtropical and tropical locations. Numerous surveys (many of them trivial, with small sample sizes) have reported a wide variety of blood and intestinal apicomplexans from 17/27 (63%) crocodilian hosts, but neither a summation for the group nor a revisionary systematic approach to species evaluation has ever been provided. Herein, we summarize information on the 16 species of apicomplexans that we consider to be valid, including 8 Eimeria, 1 Haemogregarina (that eventually may be transferred to Hepatozoon), 4 Hepatozoon, 2 Isospora, and 1 Progarnia species. In addition, there are 46 apicomplexan forms that we have relegated to species inquirendae and/or only partially identified forms that await further study. We hope this review provides a foundation for future research between parasitologists and herpetologists on parasitism of all reptiles and their relatives. Since many apicomplexans seem to be reasonably host-specific, knowledge of shared species and/or genera may assist herpetologists to better understand the phylogenetic relationships among the New World crocodilians and the direction of their dispersal in the New World.