Tuesday, June 19, 2012

More Saipan Nudibranchs

Nudibranchs are related to marine snails.  Although they are related, they do not have shells as thy shed them before they become adults.  They are amazingly varied and colorful, and people around the world "collect" them in pictures.  The name "nudibranch" means naked branch because of their exposed gills.  People more commonly call them "sea slugs" which is not a very flattering name.  Interestingly, the Japanese call them umi ushi meaning "sea cow" because they have head tentacles that look like horns.  These are sensory organs called rhinopores.

You can find a few nudis in the shallow waters of Saipan's beaches.  You just have to look carefully since they are very small, and although quite colorful, they are camouflaged well in the marine environment.  This is the Elysia ornata I found a few weeks ago in Obyan Beach.   
I found a few more this weekend that I would like to share.  I do not have an underwater camera and couldn't get a picture of the Thuridilla gracilis that I saw in Obyan last week.  I did manage to find another one at Coral Ocean Point.
She was strikingly beautiful and only about 15 millimeters long. 
Can you tell how tiny she is from the size of the sand grains in the picture?  Tiny!
Another really common nudi is Plakobranchus ocellatus that has purple and lavender spots.  I guess that is why they named it after an ocelot.  I only had a camera phone with me, so sorry if the pictures aren't that great.
They are a lot bigger than the T. gracilis, at about 30mm long and 10mm wide.  I found a few of them in the shallow reef flat of Wing Beach.

I think they must be pretty common here since I always happen upon them at several shallow beaches.  You can check out more nudibranch information and look at beautiful pictures in Nudipixel where a few of my friends have contributed their finds from Guam and Saipan. 

I think these maybe are the more common shallow water nudibranchs around here but I will keep an eye out for others.  Thanks for talking stories again.

Ti napu.
The Beachcomber

Monday, June 18, 2012

Not So Extinct Sea Urchin

Some scientists believe that the collector sea urchin (Tripneustes gratilla) is extinct on Saipan due to over collection.  Imagine my surprise to find one after more than 7 years!  Well, it may very well be extinct now since I made this one into a yummy sea urchin sashimi or uni!  Yummy!  

Just kidding!  But all jokes aside, I was very happy to find that there is still a population of collector urchins  hanging on to existence in the CNMI. Someone told me that people used to collect them by the buckets in the 1980s through the 1990s.  These urchins have short spines and they have a habit of "collecting" bits of shells, sea grass and algae that camouflages them from predators.  I still don't have an underwater camera so I had to briefly bring this one above water for a picture.  I tasted another type of sea urchin a long time ago on Guam when my dad popped one open and squeezed some lemon in it.  I remember it tasting like lemony sand.

I also found a live tulip cone snail (Conus tulipa).  Out of all the cone snails, this one resembles the deadly geography cone (C. geographus) the most, so there is speculation that it is just as deadly.  Cone snails use a harpoon-like tooth to inject their prey with venom and handling them can prove to be deadly.  So my advice: Hands off!  Check out this link that my friend Doug wrote that has video of a geography cone snail.

Thanks for talking stories with me again.  Take care, friends.

Ti napu.
The Beachcomber

Sunday, June 10, 2012

Obyan Nudibranch

I went beachcombing at Obyan Beach with the BFF this weekend.  The day was hot and sunny and the tide was really low.  In the shallow water, I saw two nudibranchs (sea slugs) but only managed to get a picture of one (sorry, I only had my phone camera).  I think this is an Elysia ornata and it was laying down its egg mass.  The other one was probably a Thuridilla gracilis.  Nudibranchs are especially hard to identify and there are people who are really into "collecting" them in pictures.  Here is a picture of the bright yellow egg mass:
Beach time with the BFF are some of the best times.  Hopefully there will be more time in the water next weekend.
Ti napu.
The Beachcomber