Phylum Ctenophora (comb jellies)

Ctenophores (Greek meaning cten, “comb”; phero, “to bear”) are mostly planktonic and about 100 species have been described. For locomotion ctenophores use eight rows of cilia that are located on the sides of the animal that are controlled by a unique apical sense organ. They are radially symmetrical, diploblastic (or triploblastic) organism, which bears a resemblance to cnidarinan jellyfish. However, they are very different from jellyfish; for example their nervous system is a nerve net that is more specialized than that of cnidarians. Many ctenophores are bioluminescent.

References:

Brusca, R.C., and Brusca, G.J. (2003). Invertebrates. Library of Congress Cataloging-in-Publication-Data: USA.

Kozloff, Eugene N. (2000). Seashore Life of the Northern Pacific Coast. University of Washington Press: Seattle and London.