Tara Oceans Expeditions - May 2011. l: Sophie Marinesque; r: Dr. Stéphane PESANT, specialist for plancton ecology, scientific coordinator on TARA; l: r: Dr. Stéphane PESANT, spécialiste de l'écologie du plancton, coordinateur scientifique sur TARA. Pyrosomes, or pyrosoma, are free-floating colonial tunicates that live usually in the upper layers of the open ocean in warm seas, although some may be found to great depth. Pyrosomes are cylindrical or conical shaped colonies made up of hundreds to thousands of individuals, known as zooids. Colonies range in size from less than one centimeter to several meters in length. Each zooid is only a few millimeters in size, but is embedded in a common gelatinous tunic that joins all of the individuals. Each zooid opens both to the inside and outside of the "tube", drawing in ocean water from the outside to its internal filtering mesh called the branchial basket, extracting the microscopic plant cells on which it feeds, and then expelling the filtered water to the inside of the cylinder of the colony. The colony is bumpy on the outside, each bump representing a single zooid, but nearly smooth, though perforated with holes for each zooid, on the inside. Pyrosomes are planktonic, which means that their movements are largely controlled by currents, tides and waves in the oceans. On a smaller scale, however, each colony can move itself slowly by the process of jet propulsion, created by the coordinated beating of cilia in the branchial baskets of all the zooids, which also create feeding currents. Pyrosomes are brightly bioluminescent, flashing a pale blue-green light that can be seen for many tens of meters. The name Pyrosoma comes from the Greek (pyro = "fire", soma = "body"). Pyrosomes are closely related to salps, and are sometimes called "fire salps." Sailors on the ocean are occasionally treated to calm seas containing many pyrosomes, all bioluminescencing on a dark night. Galapagos
©
Christoph Gerigk / Biosphoto
View author's portfolio
Rights Managed
JPEG bitmap image
Image size: 6048x4017 pixels (20.2"x13.4" @300dpi)
Shooting date : 2011-05-04
Your request has been registered.
To use this feature you must first register or login.
Log in
To organize photos in lightboxes you must first register or login. Registration is FREE! Lightboxes allow you to categorize your photos, to keep them when you sign in and send them by email.
Log in
A Biosphoto authorization has to be granted prior using this feature. We'll get in touch shortly, please check that your contact info is up to date. Feel free to contact us in case of no answer during office hours (Paris time).
Delete permanently this lightbox?
Delete permanently all items?
The lightbox has been duplicated
The lightbox has been copied in your personal account
Your request has been registered. You will receive an e-mail shortly in order to download your images.
Your album has been sent.
In case of modification, changes will be seen by your recipient.
If deleted, your album won't be avalaible for your recipient anymore.