toxocystis toxocystis toxocystis is a genus of parasites of the phylum apicomplexia. toxocystis scientific classification domain: eukaryota (unranked): sar (unranked): alveolata phylum: apicomplexa class: aconoidasida subclass: haemosporidiasina order: achromatorida genus: toxocystis species toxocystis homari only one species (toxocystis homari) is known in this genus. history this genus was described in 1910 by léger and duboscq. description this parasite is found in the caecum of the lobster homarus gammarus. host records european lobster (homarus gammarus)