Saturday, February 28, 2009

The Blue Fleet

When an email from Blair Witherington arrives with an attachment, you know it's going to be good. In Blair's words: Dawn and I went out late yesterday afternoon (Thursday) for only about 45 minutes before dusk, and we found six species (blue button, man-o-war, by-the-wind sailors, blue glaucus sea slugs, and two species of purple sea snails). The Glaucus are captivating animals. We put them in water with the by-the-winds, and in a matter of minutes the little blue slugs were munching on the tentacles of their aquarium mates. We also found several sargassum nudibranchs among their namesake golden algae. It takes a keen eye to spot those. There are also some ram’s horn squid shells drifting in. The wrack was not thick in Floridana Beach, but we did find one Mucuna and a starnut palm.
Blair sent along these two photos - the first is of the Glaucus atlanticus (blue glaucus sea slug), and the other is of the Janthina janthina (violet snail). Once I saw the photos, I knew why the subject of Blair's email was Blue Fleet is in!
We've spoken before of the beautiful blue glaucus sea slug in our December 16, 2008 post. The violet snail is also pretty cool - the foot of the snail secretes mucus that forms the raft of bubbles upon which the snail drifts in the ocean. Both feed on such yummy tidbits as by-the-wind sailors (jellyfish), known more formally as velella velella (sounds like a '70's song to me). When I was researching by-the-wind sailors, I found a link to friend David McRee's BeachHunter site, in which he describes numerous jellfish. In his entry about the by-the-winds, he includes the following quote from The Nature of Florida's Beaches, written by our late friend, Kathy Katz: "About half of them are 'left handed'...their sails are set opposite to the other half...so that during violent storms, half will be carried to shore to provide food for beach creatures while the other half will survive to continue drifting." Doesn't Nature have some glorious schemes?

In a follow-on email, Blair included this photo of two blue glaucus feeding on a by-the-wind, and this additional information: Search where the recent swash lines are pushed up. On the beach, Glaucus are puckered up like individual bright blue peas. All that we found (~10) were alive and unfolded gloriously when placed in seawater.

Our thanks to Blair for sharing his photos and his knowledge, and especially for his ability to describe a glaucus as a bright blue pea! As we've said many times before, Blair and Dawn's book, Florida's Living Beaches: A Guide for the Curious Beachcomber, is a must-have.

2 comments:

Cactus Jack Splash said...

What wonderful looking creatures! I always enjoy learning more about our aquatic friends

ChrisC and JonJ said...

The violet snail is beautiful!