These tiny crustaceans make a living by feeding on benthic marine detritus. Only nine species are known. The second pair of maxillae of cephalocarids closely resembles the appendages of the thorax. In this and other characteristics cephalocarids resemble what we imagine primitive crustaceans might have been like. Cephalocarids also lack abdominal appendages. They have small compound eyes that are buried in the exoskeleton, rather than being raised on stalks as in most other crustaceans. As in branchiopods and malacostracans, cephalocarids feed by generating currents with their thoracic appendages. These currents bring in food particles, which are trapped and and passed anteriorally along a ventral groove leading to the mouthparts.


Hickman, C.P. and L. S. Roberts. 1994. Animal Diversity. Wm. C. Brown, Dubuque, IA.

Brusca, R. C., and G. J. Brusca. Invertebrates. 1990. Sinauer Associates, Sunderland, MA.

Pearse, V., J. Pearse, M. Buchsbaum, and R. Buchsbaum. 1987. Living Invertebrates. Blackwell Scientific Publications, Palo Alto, Ca.


Phil Myers (author), Museum of Zoology, University of Michigan-Ann Arbor.


bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature