Hemolivia is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of the phylum

Phylum

In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....

 Apicomplexia.

History

This genus was described in 1990 by Petit et al.

The type specis is Hemolivia stellata.

Characteristics of the genus

The species in this genus are haemogregarines and infect exothermic vertebrates.

They have erythrocytic gamogony, both erythrocytic and extra-erythrocytic merogony and cystogony.

The definitive hosts are ixodid ticks.

Sporogony occurs in two phases. In the first phase conjugation

Conjugation

Conjugation or conjugate may refer to:* Conjugation , the modification of a verb from its basic form* Conjugate , used to rationalize the denominator of a fraction...

 and fertilization occur within the tick gut. This is followed by the formation of oocysts and the generation of sporokinetes. In the second phase the sporokinetes invade the body of the tick and give rise to sporocyst

Sporocyst

Sporocyst is a common name of a lifecycle stage in two unrelated groups of species:*Apicomplexa parasites: see Apicomplexa lifecycle stages*Trematode flatworms: see Trematode lifecycle stages...

s containing sporozoites infective to the vertebrate host.

Life cycle

The vertebrate

Vertebrate

Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...

 host

Host (biology)

In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...

 of this species is the cane toad (Bufo marinus). The invertebrate

Invertebrate

An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

 host is the tick Amblyomma rotondatum.

Toads become infected by ingesting infected ticks. The sporozoites are released from the sporocysts within the tick and penetrate the intestinal wall. Within the toad they replicate within the endothelial cells and erythrocytes. Liver cysts may form.

Circulating gamonts are then ingested by a tick. Within the tick gut the gamonts form pairs and penetrate the epithelial cells. Within these cells they associate in syzygy. Gametes are formed and fuse forming an oocyst. The oocysts are star shaped. The oocyst undergoes meiosis and then mitosis producing numerous sporozoites.

These sporozoites invade the body of the tick, undergo merogony and giving rise to many merozoites which are infective for the toad.

Host records

H. mariae - blue-tongued skink (Tiliqua rugosa)

H. mauritanica - Greek tortoise (Testudo graeca), marginated tortoise (Testudo marginata), Testudo mauritanica

H. stellata - teiid lizard (Ameiva ameiva), cane toad (Bufo marinus)

Vectors

H. mariae - Amblyomma limbatum

H. mauritanica - Hyalomma aegyptium

H. stellata - Amblyomma rotondatum.