Belongs within: Siphonostomatoida.
The Cancerillidae are a family of marine copepods parasitic on echinoderms.
Characters (Sars 1915): Two or tree posterior trunk-segments imperfectly developed, without any epimeral plates. Tail short or moderately produced, with somewhat varying number of segments. Anterior antennae normal. Posterior antennae transformed into strong prehensile organs terminating in a powerful curved claw. Siphon imperfectly developed, in some cases obsolete. Mandibles short, mucroniform, extending straight inwards, palp absent. Maxillae likewise incurved, terminating in one or two setiferous lobes. Maxillipeds somewhat widely attached from median line. Some posterior pairs of legs imperfectly developed or quite absent, this imperfect development in some cases even extending to all legs (in female).
<==Cancerillidae [Cancerillinae]BO01
|--Ophiopsyllus reductusBO01
|--Parophiopsyllus ligatusBO01
|--Parartotrogus Scott & Scott 1893BO01
| |--*P. richardiS15
| `--P. arcticus [=P. richardi var. arctica]S15
`--Cancerilla Dalyell 1851 [incl. Caligidium]S15
|--C. durbanensisBK77
|--C. neozelanicaBK77
|--C. tubulata Dalyell 1851IFS01 [incl. Caligidium vagabundum Claus 1889BK77]
`--C. vulgarisD56
*Type species of generic name indicated
References
[BK77] Barel, C. D. N., & P. G. N. Kramers. 1977. A survey of the echinoderm associates of the north-east Atlantic area. Zoologische Verhandelingen 156: 1–159.
[BO01] Boxshall, G. A., & S. Ohtsuka. 2001. Two new families of copepods (Copepoda: Siphonostomatoida) parasitic on echinoderms. Journal of Crustacean Biology 21 (1): 96–105.
[D56] Dawes, B. 1956. The Trematoda with special reference to British and other European forms 2nd ed. University Press: Cambridge.
[IFS01] Ivanenko, V. N., F. D. Ferrari & A. V. Smurov. 2001. Nauplii and copepodids of Scottomyzon gibberum (Copepoda: Siphonostomatoida: Scottomyzontidae, a new family), a symbiont of Asterias rubens (Asteroidea). Proceedings of the Biological Society of Washington 114 (1): 237–261.
[S15] Sars, G. O. 1915. An Account of the Crustacea of Norway with short descriptions and figures of all the species vol. 6. Copepoda. Cyclopoida pts 9–10. Ascomyzontidae (concluded), Acontiophoridae, Myzopontiidae, Dyspontiidae, Artotrogidae, Cancerillidae. Bergen Museum: Bergen.