The world's most prevalent animal is one of the least observed, but scrutiny by a University of Hawaii researcher may change the way scientists look at little insectlike ocean-dwelling invertebrates known as calanoid copepods. Copepods are members of the zooplankton, drifting animals of the seas.
Calanoid copepods are only three millimeters long and eat phytoplankton, or plant plankton.
They constitute the biggest source of protein in the ocean and form a critical link in the marine food chain between the phytoplankton on which they feed and the krill, fish and whales that in turn feed upon them. The researcher's work has implications for the study of evolution as well as the understanding of the biology of the oceans. Myelin is a white fatty sheath that coats parts of the vertebrate nervous system, including the long axons of nerve cells. Like insulation on an electric wire, myelin protects and speeds the electrical signal, providing a competitive advantage for organisms that must respond quickly to capture food or escape predators. Such an advantage is particularly important for large animals, in which nerve signals must travel long distances from sensory cells to brain and brain to muscles, and scientists had assumed myelin was a feature nearly exclusive to vertebrates.