Cycliophorans are the most recently discovered animal phyla (Funch & Kristensen 1995). They are minute sessile organisms that live on the mouthparts of the Dublin Bay prawn or Norway lobster Nephrops norvegicus.
A lack of morphological data has made the true phylogenetic relationship of Cycliophora difficult to determine, however examination of its ribosomal RNA (Winnepenninckx et al. 1998) has revealed a close relationship with acanthocephalans and rotifers.The phylum is at present represented by one species which has been recorded from Denmark, Sweden, the Faeroes Islands and the Firth of Clyde, UK (O'Reilly 1997). It appears likely its distribution is related to that of its host.
- Funch, P. & Kristensen, R. M. 1995. Cycliophora is a new phylum with affinities to Entoprocta and Ectoprocta. Nature 378: 711-714.
- O'Reilly, M. G. 1997. Cycliophora. In: The species directory of the marine fauna and flora of the British Isles and surrounding seas, Howson, C. & Picton, B. E., (eds). Belfast and Ross-on-Wye, Ulster Museum and the Marine Conservation Society 508 pp.
- Winnepenninckx, B. M. H., Backeljau, T. & Kristensen, R. M. 1998. Relations of the new phylum Cycliophora. Nature 393: 636-637.