(No common name)

ORDER

Copelata

FAMILY

Oikopleuridae

TAXONOMY

Oikopleura dioica (Fol, 1872), Mediterranean Sea.

OTHER COMMON NAMES

None known.

PHYSICAL CHARACTERISTICS

Smallest of all appendicularians with a body length to 0.1 in (3 mm) (trunk, 0.04 in [1 mm]; tail, 0.08 in [2 mm]). House approximately 0.2 in (4 mm) long.

DISTRIBUTION

Cosmopolitan in tropical and temperate waters in epipelagic zone (less than 656 ft [200 m]). (Specific distribution map not available.)

HABITAT

Can be abundant in coastal surface waters and is one of the most common appendicularians worldwide.

BEHAVIOR

When the filters become clogged, the house is abandoned, and a new house is inflated. Studies have shown that on average a new house can be made every 4 hours.

FEEDING ECOLOGY AND DIET

Filters only the smallest particles out of the water (less than 0.0004 in [1 µm]). Some fish, such as the blacksmith Chromis bipunctata in California kelp forests, are known for feeding almost exclusively on Oikopleura dioica.

REPRODUCTIVE BIOLOGY

Separate male and female forms release their sperm and eggs into the surrounding water.

CONSERVATION STATUS

Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

None known.