Creseis acicula
(Rang, 1828)
Order: THECOSOMATA
Suborder: EUTHECOSOMATA
Family: Cavoliniidae
PHOTO
Monterey Bay Aquarium 3, Monterey County, California, USA. 1996. Photos: Daniel Geiger. (left photo of preserved specimen labelled by Bill Rudman). Shell length approx 7mm.
Thecosome pteropods such as Creseis acicula are a group of planktonic sea slugs with either an external lightly calcified shell or a leathery pseudoconch. They are plankton feeders, catching their prey by producing mucous speherical webs or flattened nets, some of which can be up to 2 meters in diameter.
Creseis has a needle-shaped, lightly calcified external shell, and a pair of wing-like flaps which are used in swimming. It feeds by trapping other plankton in a transparent muccous wen which it suspends above it in the water. The web is drawn into the mouth at intervals and food particles, including both plant and animal plankton, ingested.
Reference:
• Lalli, C.M. & Gilmer, R.W. (1989) Pelagic Snails. The biology of holoplanktonic gastropod molluscs. Stanford University Press: Stanford, California.
Rudman, W.B., 2000 (July 4) Creseis acicula (Rang, 1828). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/cresacic
