Behaviour

Like other thoracican barnacles, Capitulum mitella is a suspension feeder.

It filters zooplankton from the water passing through the cirral net that is formed from the posterior five pairs of biramous thoracic legs (cirri) and extended into the water current.

It uses the remaining smaller anterior first pair of thoracic appendages to pass captured food to the mouthparts for ingestion.

Associations

In Hong Kong, the nemertean worm Nemertopsis quadripunctatus is a common associate of C. mitella and is found in the mantle cavity of the barnacle.

The worm can reach 8cm in length but is only 1mm wide.

It feeds on the brooded eggs of the barnacle which are housed in the mantle cavity, and may also feed on material filtered by the barnacle.

Glossary
Hermaphrodite

An animal that has reproductive organs of both males and females of the species, and can act as ‘male’ or ‘female’ in the reproductive process.

Nauplius

First stage larvae of crustaceans.

Phytoplankton

Tiny water dwelling plants.

Lower eulittoral zone

An area of shoreline that ranges from the high water mark to areas that are permanently submerged.

Sessile

Permanently attached and not free to move.