Developmental cycle of chelonian haemogregarines in leeches with extra-intestinal multiple sporozoite oocysts and a note on the blood stages in the chelonian hosts

Abstract

Gametocytes and oocysts of chelonian haemogregarines: Haemogregarina pelusiensi and Haemogregarina sp. are described from natural leech hosts: Placobdella multistrigata and P. costata. The chelonian hosts were Pelusios sinuatus from South Africa and Mauremys caspica from Israel, respectively. Oocyst stages in leeches migrate from the intestine into the surrounding connective tissue and form over 40 naked sporozoites. Blood stages from both chelonian hosts are similar in structure and size despite their hosts representing very distinct chelonian taxa. INTRODUCTION Phloxine (H-E-P). Blood smears from chelonians were taken from the clipped tip of the tail. Air dried smears Accounts have been given on the development in were fixed with absolute methyl alcohol and stained 15 leech of Haemoyregarina stepanowi by Reichenow min in l / ? diluted Giemsa stock with pH 6.8 phosphate (1910) (type species of the genus Haemogregarina) of buffer. H. nicoriae by Robertson (1910) and of H. balli by Paterson & Desser (1976). These reports describe gametocytes attached to the leech's intestinal epithelia1 RESULTS surface and developing via syzygy into small oocysts. The latter divide into 8 naked sporozoites while still Developmental stages were demonstrated in: (a) the attached to the intestine. All 3 of these haemogregar-leech Placobdella multistrigata, found attached and ines are parasites of chelonians (in Europa, Sri-Lanka feeding on naturally infected Pelusios sinuatus and USA respectively). obtained from the vicinity of Pietersburg, northern The present communication describes gamogonous Transvaal, South Africa; (b) the same species of leeches development of haemogregannes from the chelonians and chelonian from the same locality, maintained for Pelusios sinuatus from South Africa and Mauremys l yr in a laboratory aquarium; (c) laboratory bred caspica from Israel, in leeches which yield extraintest-Placobdella costata examined 12 to 15 d after taking inal oocysts with numeous sporozoites. A brief account their 2nd or 3rd blood meal from naturally infected on the blood stages in the chelonian hosts is provided. Mauraemys caspica from Lake Kinnereth, Israel. In both Placobdella multistrigata and P, costata, the gastric ceaca contents included released trophozoites MATERIALS AND METHODS and encapsulated, rarely released gametocytes, but never further developmental stages. In both leeches, Leeches fixed in neutral buffered formalin (10%) macrogametocytes associated with microgametocytes were processed for methyl-methacrylate/glass knife and zygotes were found attached to the surface of the histology by the Lulham (1979) method. Sections, 3 to 4 epithelium of the intestine (Figs. 1 to 6). Such mac-pm thick, were stained by Meyer's Haemalum-Eosin-rogametocytes and zygotes measured 7 to 8 X 6 to ? pm