Blood proteins in bipolar Priapulida

Molecular weights are provided for 44 blood serum proteins from four species of Priapulida: 21 peptides in Priapulus caudatus and P. tuberculatospinosus, 19 in Priapulopsis bicaudatus, and 24 in P. australis. One (exceptionally two) proteins predominate in the investigated sera. While electrophoretic patterns are variable within species, phenetic trees constructed on the basis of Czekanowski's distances of peptide pattern resemblance match the taxonomic hierarchy of priapulids. This shows that electrophoretic profiles of denatured serum peptides have a phylogenetic basis, in spite of considerable nongenetic diversity which limits phylogenetic interpretations of the present data set. One may tentatively conclude that molecular differentiation of bipolar priapulids is more extensive than morphological differences, at least in the genus Priapulus.