Brittle star immune and genomic studies

In 2015 we discovered the sea star(asterid) IGKappa gene and a sea star primitive antibody. 2 years later we discover an ophuirid IGKappa gene in OPHIOCOMINA NIGRA which is the first sister of the sea star: Asterias rubens . It's like a big-bang in the immuno-genomics of INVERTEBRATES.So 2 classes of Echinodermata out of five possess an IGKAPPA gene which induce a primitive antibody a Fab fragment gene and a Fc receptor gene. We recall that the class of echinid has no lymphocytes no IGkappa gene; the class of holothurid has no lymphocytes.Now we have a look on the last class: the crinoïd.