Evolution, origins and diversification of parasitic cnidarians
Okamura, B.; Gruhl, A. (2021). Evolution, origins and diversification of parasitic cnidarians, in: De Baets, K. The evolution and fossil record of parasitism. Topics in Geobiology, 49: pp. 109-152 In: Topics in Geobiology. Plenum: New York. ISSN 0275-0120, more |
| Keywords | Cnidaria [WoRMS]; Myxozoa [WoRMS]; Polypodium Ussow, 1885 [WoRMS]
Marine/Coastal | | Author keywords | Myxozoa; Polypodium; Adaptations to parasitism; Life-cycle evolution; Cnidarian origins; Fossil record; Host acquisition; Molecular clock analysis; Co-phylogenetic analysis; Unknown diversity |
| Abstract | Parasitism has evolved in cnidarians on multiple occasions but only one clade—the Myxozoa—has undergone substantial radiation. We briefly review minor parasitic clades that exploit pelagic hosts and then focus on the comparative biology and evolution of the highly speciose Myxozoa and its monotypic sister taxon, Polypodium hydriforme, which collectively form the Endocnidozoa. Cnidarian features that may have facilitated the evolution of endoparasitism are highlighted before considering endocnidozoan origins, life cycle evolution and potential early hosts. We review the fossil evidence and evaluate existing inferences based on molecular clock and cophylogenetic analyses. Finally, we consider patterns of adaptation and diversification and stress how poor sampling might preclude adequate understanding of endocnidozoan diversity. |
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