Friday, March 28, 2008

Live Shells On A Night Dive

One of my favorite things about night diving is that you see so many things that you hardly ever see during the day. Typically live shells like this Tritan's Trumpet are tucked way back into holes and between rocks during the day, but at night you will find them out crawling around hunting. They are one of only 2 known predators for the Crown of Thorns, Tritan's Trumpets and Napolean Wrasse are the only ones capable of taking on the poisonous Crown of Thorns and eating them. The big fleshy part that is attached to the ceiling is called the foot of the animal.In this shot you see the operculum, it is the door that the animal seals the opening of the shell with when it pulls itself back into the shell. It helps protect them from becoming a next meal for some of their predators. You can also see his antennae or feelers leading the way in front of him.
And in this shot you can see his eyes on the sides of the feelers, they are very tiny and are fixed to the antennae unlike some other shells, like a spider conch in which the eyes are on the end of long tubes that can come out of the shell and check things out before the animal comes out itself. These guys are just totally fascinating to me, and make for great photography subjects.
Then I came across this little cone shell hunting along one of the walls. I'm not sure of the correct identification for this one, so I'm going to have to go visit Doug and find out what it is. You can see the siphon tube sticking out the small end of the shell, the cone shells have little darts or harpoons that they shoot out through those tubes which contain neuro-toxins which paralyze their prey allowing them to envelop and consume them. Some of these small cone shells are so poisonous they have been known to kill people as well. Usually it will be because the toxins shut down the respiratory system of the victim and they drown.
In this shot you get a pretty good look at the foot on this cone as it cruises over the coral, and at the pink tip at the end of the shell. I'm still waiting to see one of these guys actually attack another shell and surround it. But I'm sure if I keep looking long enough, sooner or later I'll get my wish. I definitely need to do more night diving!

2 comments:

John Dax said...

Can I take a stab at the I.D., Harry? The mantle of the cone and the shape and pattern of the shell looks like it is a Geography cone. It may be a young specimen since you said it was small and looking more closely at your Smugmug pics, I see a small pink protoconch on the tip of the shell. Some young cones will still have a remnant of the first shell they developed during their larval stage. Awesome finds!

Wangbu said...

Though I can stand longer periods under water, I almost seem to try scuba diving by just looking at your pictures. I am Wangbu, from the Philippines and you have a very artistic blog.