Biodiversity & Conservation

By-the-wind-sailor - Velella velella - General information

Velella velella

Image Steve Trewhella - By-the-wind-sailor, Velella velella. Image width ca XX cm.
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Distribution map

Velella velella recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

Why do the maps differ?

Sightings Have you seen Velella velella?
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Velella velella is not listed under any importance categories.

General information

Key Icon Researched by: Olwen Ager Text page icon Refereed by:

Taxonomy icon Taxonomy

Phylum Cnidaria Sea anemones, corals, sea firs & jellyfish
Class Hydroidomedusa
Map icon Recorded distribution in Britain and Ireland Velella velella is an ocean dwelling species that is occasionally seen in the open sea and washed up around British and Irish coasts (see additional information below).
Habitat information icon Habitat information Velella velella is a pelagic species but is occasionally seen washed up around Britain and Ireland.
Text page icon Description Velella velella is a pelagic colonial hydroid. The float, which is an oval disc, is deep blue in colour and can be up to 10 cm in length. Short tentacles hang down into the water from the float. A thin semicircular fin is set diagonally along the float acting as a sail. This sail gives the animal both its scientific (i.e. from velum, a sail) and its common name, 'by-the-wind-sailor'. The direction of the sail along the float determines which way Velella velella will travel. If the sail runs north-west to south-east along the float it will drift left of the wind direction, if the sail runs south-west to north-east it will drift right of the wind direction. Velella velella feeds on pelagic organisms, including young fish, caught by stinging cells on its tentacles. The sea slug Fiona pinnata , sunfish Mola mola and violet snail Janthina janthina prey upon Velella velella.

This review can be cited as follows:

Olwen Ager 2008. Velella velella. By-the-wind-sailor. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 03/09/2010]. Available from: <http://www.marlin.ac.uk/speciesfullreview.php?speciesID=4560>