Happy Holidays from The Right Blue

We wish all of our readers a happy, festive and safe holiday season. We're taking a break for the holidays, but we hope to see all of you again early in the new year. We have a few surprises in store for our readers in 2010. Meanwhile, stay well and enjoy yourselves.

Happy Holidays!

Bobbie & Jerry

Labyrinthine brain coral

What: Macro photo of the surface of a Labyrinthine brain coral (Diploria labyrinthiformis).

The polyps, which usually extend at night, live in the 'valleys' between the ridges.

These corals form hemispherical heads that can grow to four feet in diameter.

Where: I photographed this coral off the coast of Grand Cayman.  This species is found throughout the Caribbean and is also found around the Bahamas and south Florida.

Wreck diving: Beware of entanglement

by B. N. Sullivan

What:  This photo of Jerry ascending from a wreck dive is a reminder that the potential for entanglement is one of the hazards of diving on natural wrecks.  Wrecks that have been intentionally sunk as artificial reefs and diver playgrounds usually are prepared ahead of time to minimize hazards that could lead to diver entanglement or entrapment.   Doorways and portholes are removed or welded open, and cables, lines, and other sources of entanglement are taken off the vessel.  This is not the case with natural wrecks, i.e., vessels that have sunk as a result of an accident, or war.  Proper training in wreck diving will educate the diver about how to recognize and cope with the risks entailed in diving on natural wrecks.

Where:  I took this photo of Jerry at the site of the wreck of the Zenobia, a modern ship that sank in 1980 off the coast of Larnaca, Cyprus.  The Zenobia was a huge vessel, more than 172 meters (560 feet) in length, with a beam of about 23 meters (75 feet).  Click here to see a photo of the Zenobia, just before she sank.

We made a number of dives on the wreck of the Zenobia in the 1990s.  In case you missed our series of articles about those dives (with photos), here they are:

• Diving the Wreck of the Zenobia - Introduction
• The Wreck of the Zenobia - A Brief History
• First dives on the wreck of the Zenobia
• Bottom Time on the Wreck of the Zenobia
• Diving Inside the Zenobia's Parking Deck
• Final Dives on the Wreck of the Zenobia
• Photo: Our friend Joe photographs Jerry on the wreck
• Photo: Diving on the Wreck of the Zenobia

The Octopus: Nature's ultimate shape shifter

by B. N. Sullivan

We have encountered octopuses frequently wherever we have dived, and they are fascinating creatures to observe underwater. They can change their coloration and the texture of their skin readily to camouflage themselves.  Take a look at the above image of a Caribbean Reef Octopus (Octopus briareus), which I photographed in the Cayman Islands. It can change its skin color from a dark reddish shade to the almost iridescent green you see here.  The skin texture can change from smooth, to rough or prickly looking to mimic the surface texture of the rock or coral on which the octopus is resting.

Octopuses also can squeeze through incredibly small spaces, since they have no skeleton, either internally or externally.  We have seen these creatures slide their bodies between lobes of coral that were practically touching each other, and flatten themselves to pass through a crack in the wall of a cavelet. It's a most amazing sight -- almost magical.

I recently discovered the video below on YouTube.  It had no accompanying explanatory information other than its title -- "Octopus escaping through a one inch hole" -- but it appears to be an experiment to illustrate the shape shifting ability of the octopus. At the beginning of the video, the octopus is inside what looks like a clear lucite box.  In the course of the next 30 seconds, the octopus manages to extricate itself from the box by passing through the round hole in the side of the box -- and quite effortlessly at that.

Watch the video and you will  see why we think of the octopus as Nature's ultimate shape shifter!

If the video does not play or display properly above, click here to view it on YouTube.

Hat tip to YouTube user defosterr, who posted the video to YouTube three years ago.

Bet you can't eat the whole thing!

What: A Striped Pajama nudibranch (Chromodoris quadricolor) browsing on a brightly colored sponge (Negombata sp.), which is the favorite food of this nudibranch species.

Where: I photographed this nudibranch in the Red Sea, at Tiran Island.