The life cycle of a species of Hematodinium has only been described from in vitro cultures of the parasite from the Norway lobster (Appleton & Vickerman 1998). There may be differences in the life cycle of species from hosts that live in boreal habitats vs. those from temperate habitats. 

The in vitro life cycle of Hematodinium sp. from the Norway lobster (from Appleton & Vickerman 1998).

Excerpted from Stentiford & Shields (2005): "In culture, the macro- and microdinospores give rise to the filamentous trophont that develops into an assemblage of filamentous forms known as a “Gorgonlocks”. The vermiform filamentous trophont has been described from the hepatopancreas of the Norway lobster (Field & Appleton 1995, 1996) and appears to be identical to the motile vermiform plasmodium of Chatton and Poisson (1931) and Shields & Squyars (2000). The Gorgonlocks develops into either a “clump” colony that develops into more filamentous trophonts, or it develops into a bizarre web-like plasmodial mass known as an arachnoid trophont. This becomes an enlarged arachnoid sporont that undergoes sporogony to produce sporoblasts that then develop into the macro or micro form of the dinospore."

The life cycle of Hematodinium isolated from the blue crab, C. sapidus, appears to be different from that above. In the blue crab, the filamentous trophont undergoes budding to reproduce more plasmodia, or it undergoes an apparent schizogony analogous to the schizogonous segmentation of malarial parasites. The amoeboid trophonts separate during segmentation, and in turn undergo fission to produce additional trophonts. The amoeboid trophonts undergo a final fission to produce a rounded stage that may be a sporoblast, which  then undergoes sporogonal division to produce four dinospores.

This figure shows the life history of the parasite from the blue crab, Callinectes sapidus. This has further discussion in Stentiford & Shields (2005)