IMIS

Class Myxozoa is a group of obligate parasites consisting of over 3015 species, representing about 15 % of the known cnidarian biodiversity (WoRMS Editorial Board, 2025). Myxozoans have complex life cycles that involve invertebrate and vertebrate hosts (Fiala et al., 2015; Okamura et al., 2015; Miller, 2024). Definitive hosts are annelids and bryozoans. Fishes represent the majority of intermediate hosts, although amphibians, reptiles, birds, monogeneans and mammals are also parasitized (Eszterbauer et al. 2015). In general, myxozoans infect a broad diversity of host species, but many individual species show high levels of host and organ specificity. Some species cause serious damage to their hosts, which may be important to humans when these hosts have economic and ecological value (Kent et al. 2001; Mackenzie & Kalavati, 2014).

The World list of Myxozoa was introduced in 2024 as a single source of myxozoan taxa and their synonyms. It is part of the World Register of Marine Species (WoRMS), a global initiative to provide an online register of scientific names of all marine organisms and their non-marine relatives. It is continuously updated.

Users can find the taxonomic classification of myxozoans, with valid and invalid names of families, genera and species. The List provides the original source in which they were published (if known) and additional references that detail geographic range and host diversity. It also reports on their environment, distinguishing between freshwater, marine, brackish, and terrestrial habitats.

Records are based on published references that are valid according to the International Code of Zoological Nomenclature. This implies that new taxa published in online-only articles should have the article registered in ZooBank to be considered valid.