Haemogregarine specificity in two communities of Florida snakes, with descriptions of six new species of Hepatozoon (Apicomplexa : Hepatozoidae) and a possible species of Haemogregarina (Apicomplexa : Haemogregarinidae)

Five species of snakes in Florida, from Palm Beach County in the south and Alachua County 450 km to the north, occur in similar habitat but have disti nctive Hepatozoon species characteristic of each host species. In Palm Beac h County, Diadophis punctatus is host to Hepatozoon punctatus n. sp., Thamn ophis sauritus sackenii to Hepatozoon sauritus n. sp., and Nerodia fasciata pictiventris to Hepatozoon pictiventris n. sp. In Alachua County, N. fasci ata pictiventris is parasitized by Hepatozoon fasciatae n. sp.. Seminatrix p. pygaea by Hepatozoon seminatrici n. sp., and Thamnophis s. sirtalis by H epatozoon sirtalis n. sp. Each Hepatozoon sp. has distinctive gamonts and s porogonic characters and. in the 4 species where known, meronts. Nerodia fl oridana is host to Haemogregarina floridana n. sp. in both localities, with generic identification tentative, based upon presence of erythrocytic mero nts. The presence of sporocysts in the proboscis of 31% of Aedes aegypti in fected by H. pictiventris is the first report of infective stages of a rept ilian Hepatozoon species within the mouthparts of a dipteran vector. This s tudy suggests that in Florida, at least, the diversity of the Hepatozoon co mmunity not only equals but probably exceeds the diversity of the snake com munities present, and that host specificity in nature may be much greater t han that postulated from previous studies.