|Abnormal forms in the brittle-star Amphipholis squamata: a field study|Dupont, S.; Mallefet, J. (2002). Abnormal forms in the brittle-star Amphipholis squamata: a field study. J. Mar. Biol. Ass. U.K. 82(3): 491-493. dx.doi.org/10.1017/S0025315402005763
In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Cambridge. ISSN 0025-3154, more
Deviation from pentamerism is a rare phenomenon in 5-armed echinoderm species. Qualitative and quantitative data front field observations of 14 populations around the world were used for a biogeographical study of this phenomenon, Four abnormal forms presenting deviation from the classical pentamerism of echinoderms were observed within the brittle-star species Amphipholis squamata (Echinodermata: Ophiuroidea). Although these forms were rare in global populations (0.29%), they call reach important frequencies in some locations. Our results suggest that habitat structure has all influence oil the occurence of abnormal forms. Moreover, deviations from pentamerism are not a heritable character but are a consequence of environmental perturbations oil the metamorphosis of larvae and/or abnormal regeneration of arms.