Ultrastructure of Hemolivia mariae gamonts in the blood of the lizard Tiliqua rugosa and their development to oocyst stage in the tick Amblyomma limbatum

Abstract

The ultrastructural features of the development of Hemolivia mariae from intra-erythrocytic gamonts in their host, the Australian lizard Tiliqua rugosa, to oocysts containing sporokinetes in their vector, the tick Amblyomma limbatum, are described. Mature intra-erythrocytic gamonts, as well as gamonts ingested by the tick were encased in a thick (30 nm) capsule with distinct suture sites at each of the two apices. In the only image of a presumed syzygy, both partners were still encased. Further stages, the young and ongrowing oocysts, were bound by a membranous wall. Sporokinetes developed within the oocyst around a primordial crystalloid body. The fully differentiated sporokinetes, still resting within the oocyst wall, exhibited a very short conoid in the apical complex and were heavily loaded with crystalloid material.

Ultrastructure of developmental stages of Hemolivia stellata (Apicomplexa: Haemogregarinidae) in the cane toad Bufo marinus and in its vector tick Amblyomma rotondatum

“…Except for storage granules, few other structures are detectable in the encapsulated gametocytes; Beyer and Sidorenko (1984) claimed a considerable reduction of cytoplasmic components occurring in the encapsulated waiting-stage gametocytes of``Karyolysus''. In our opinion, these structures were obliterated due to processing faults: TEM images of pre-and post-fertilized stages of H. mariae in the tick (Smallridge and Paperna 2000b) appear to retain all ®ne structural components seen in H. stellata premature gametocytes in the vertebrate host.…”

“…These gametocytes were impermeable to Giemsa stain in blood smears (Petit et al 1990;Smallridge and Paperna 2000b), while in TEM their assumed shrunken image evidently results from the partial resistance of their hardened wall to ®xation and in®ltration. Encapsulated gametocytes with similar processing faults, but no demonstrated presence of sutures, have been seen in the``Karyolysus'' sp.…”

Light and transmission electron microscopic studies of a haemogregarine in naturally infected fan-footed gecko (Ptyodactylus hasselquistii)

“…(Abdel-Ghaffar et al 1994;Ibrahim 1998). The gamont of Hepatozoon gamezi was studied using light and electron microscopy from the lizard, Ctenosaura similis (Desser 1997), and gamonts of Hemolivia mariae in the blood of the lizard, Tiliqua rugosa (Smallridge and Paperna 2000). The blood stages of Haemogregarina sp.…”

Ultrastructure studies on post-oocyst development of the lizard hemogregarine Hemolivia mariae in the tick Amblyomma limbatum

“…Methods for the rearing, maintenance and infection of ticks as well as methods for transmission electron microscopy (TEM) were described in a previous communication (Smallridge and Paperna 2000). Visceral parts for electron microscopy were dissected from engorged nymphs at days 14, 20 and 27 after detachment from their lizard host and after they had molted into adults at 33 and 75 days post-detachment.…”

“…Light microscopy studies (Petit et al 1990;Landau and Paperna 1997) and preliminary ultrastructural analysis (Smallridge and Paperna 1997) suggest that some hemogregarinids developing in acarina have unique ways of developing. In a preceding communication, ultrastructural details of the development of the hemogregarinid Hemolivia mariae, from the entry of gamonts to the ®nal stage of oogenesis in ticks, has been reported (Smallridge and Paperna 2000). Oocyst division yields motile progeny ± the sporokinetes (Petit et al 1990).…”