Kinorhynchs: Kinorhyncha

Physical characteristics: The trunk of Echinoderes sensibilis kinorhynchs is 0.012 to 0.014 inch (320 to 350 micrometers) long and yellowish. The head has 91 spines arranged in seven circles. There are hairlike fibers on some trunk segments.

Geographic range: Echinoderes sensibilis (abbreviated as E. sensibilis) kinorhynchs live on the Pacific coast of Japan.

Habitat: E. sensibilis kinorhynchs live in saltwater pools in areas that are exposed at low tide.

Diet: E. sensibilis kinorhynchs eat diatoms.

Kinorhynchs move by contracting the muscles on the top and bottom of their body. This process plows the spines into the sand or mud and pushes the worm forward, at the same time forcing its head out of the trunk. When the worm relaxes its muscles, the head is pulled back into the trunk. (Illustration by Amanda Humphrey. Reproduced by permission.)

Behavior and reproduction: Scientists do not know how E. sensibilis kinorhynchs behave. The young shed six times as they grow into adults.

Echinoderes sensibilis and people: E. sensibilis kinorhynchs have no known importance to people.

Conservation status: E. sensibilis kinorhynchs are not considered threatened or endangered. ∎