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Velella velella

Text by Vicki Osis, marine education specialist, Sea Grant Extension, Oregon State University.

© 2003 by Oregon State University. This publication may be photocopied or reprinted in its entirety for noncommercial purposes.

ORESU-G-03-004

Graphics omitted. A printable .pdf version with all graphics is also available.

Usually in spring, but occasionally in winter, great windrows of blue- to purple-bodied jellyfish line our beaches. The scientific name of the jellyfish is Velella velella.

A good common name is "by-the-wind sailors," or you might prefer the shorter "purple sailor." Some Northwest beachcombers call them "Portuguese man-of-war," but this is incorrect; the man-of-war lives only in warm waters.

Velella is an offshore resident. Winds blowing gently against its triangular, clear sail move the jellyfish. The sail is set diagonally to the long axis of the animal. On our side of the north Pacific Ocean, their sails are set in a northwest to southeast direction. On the other side of the north Pacific, the sails are set in a northeast to southwest direction. In the southern hemisphere, sails are reversed. As long as the winds blow gently, Velella tacks at about 45° away from a following wind. This keeps the animal offshore.

When winds are strong, Velella loses its tacking ability and begins spinning and more directly follows the wind. Strong westerlies, then, are what drive these animals onto our beaches.

All jellyfish have stinging cells in their tentacles. Most people are not bothered by touching one from our beaches with their hands. You should not rub your eyes or put a finger in your mouth after handling a jellyfish, however, because this could cause you pain--and maybe even more serious problems. You should also avoid walking barefoot through freshly beached jellyfish. Velella is not the only jellyfish you might find on your beach walks. The moon jelly, Aurelia, usually appears as a flat, clear blob. If enough of the moon jelly remains, you might see four horseshoe-shaped gonads, purple in males and yellow in females. West coast sea nettle (Chrysaora fuscenscens) is tan with reddish-orange hues and has very long tentacles. Its sting can be mildly harmful to humans, about as potent as a bee sting.

This publication was funded by the National Sea Grant College Program of the U.S. Department of CommerceÕs National Oceanic and Atmospheric Administration, under NOAA grant number NA16RG1039 (project number A/SGE-5), and by appropriations made by the Oregon State legislature. The views expressed herein do not necessarily reflect the views of any of those organizations.

Note: This is an accessible version of a document originally produced for the Web in .pdf format. While it contains all significant content of the original print document, it may omit layout and graphic elements which contribute to the look and feel of the original, and make the .pdf version more suitable for printing.