OPHIOTHRIX SYNOECINA NEW SPECIES (ECHINODERMATA, OPHIUROIDEA) FROM THE CARIBBEAN COAST OF COLOMBIA

A new species, Ophiothrix synoecina, is described and figured. O. syno ecina differs from its Caribbean congeners in spination of disk and ar ms and in its color pattern. The disk of O. synoecina bears short, sto ut stumps, the arm spines are flattened and uniform denticulated. Some individuals are dark blue-grey, others have banded arms. O. synoecina is an obligate associate of the regular sea urchin Echinometra lucunt er (L.) in the area of Santa Marta on the Caribbean coast of Colombia. The rock-boring echinometrid E. lucunter inhabits heavily exposed are as of rocky shores. O. synoecina lives in the boreholes excavated by t he sea urchin, spending its life under the echinoid.