Posts: 589
Threads: 20
Joined: May 2006
Any of you tidepool aficionados know what the following is? Today, I was down at Punalu'u Black Sand Beach and saw some mollusk-like critters clinging to the rocks at the water's edge. They were hemispherical in general shape, dark brown, had (hexagonal?) plates like on a turtle's carapace, and a skirt of longer plates around the edge, arranged like a hula skirt made of ti leaves. They appeared to be gobbling up the vegetation on the rocks as the areas they occupied had no vegetation and were pinkish. There were lots of them of several sizes, largest about the size of a half a tennis ball, down to the diameter of a large $1 coin.
Posts: 6,214
Threads: 354
Joined: Feb 2006
Les, it sounds sorta like a green chiton, Acanthochiton viridis, except the shirt really isn't plates. Check out this link to see if this is it:
http://www.marinelifephotography.com/mar...hitons.htm
Aloha, Carey
Posts: 589
Threads: 20
Joined: May 2006
Carey,
Nope, not that chiton. The critter I saw was round, not oblong, when viewed from above. And the skirt did appear to be composed of separate elongated plates. It wouldn't surprise me if these plates could be individually articulated.
I've been searching the web for images with little success. I think it's a mollusk and looks like a gastropod (stomach foot). It clings to the outer edge of the rock shelf exposed at low tide. As far as I could tell, it was a gastropod, hanging out where you'd expect to find opihi. I suspect that it might not be a native species and may be affecting the coastal habitat by denuding the rocks of vegetation. I don't know if the vegetation on these rocks are native. Some of it appears to be ogo and other edible seaweeds.
Posts: 6,214
Threads: 354
Joined: Feb 2006
Les, what about a shingle or helmet Urchin Colobocentrotus atratus
There are a bunch of urchins on this page, scroll down about 1/2 way for the Colobocentrotus:
http://www.marinelifephotography.com/mar...rchins.htm
ALoha, Carey
Posts: 589
Threads: 20
Joined: May 2006
Carey,
Bingo! That's it! I remember now that I thought it was reminiscent of an urchin. I've never seen an urchin like this in Island waters before. And I used to think that all urchins were "Wana" and spiny. It has an Hawaiian name, "Ha'uke'uke" and it appears to be a native urchin species. The intertidal areas that it occupied and fed appeared pinkish after it scraped off the algae.
How did you find it!? I couldn't think of what category to search beyond mollusks. Good sleuthing!
Posts: 6,214
Threads: 354
Joined: Feb 2006
It was one of the critters I had to know for a UH-Hilo Quest Marine Science class ( the clues of round & skirt of elongated plates & the fact that it was not a chiton, which has overlapping plates like the Hawksbill sea turtle) The fact that I had to look up the name tells you how well my memorization works! Only remebered there was an urchin with inter-tidal flatten spines & it had lobocentrus in the name, but had my class materials to fall back on!
Aloha, Carey
Posts: 1,516
Threads: 81
Joined: Dec 2005
LOL Carey...you are officially the Geek Queen! ROFLOL!!! Here's to our very own professional student! I know if I have a question about anything here, you are the perfect detective!
Carrie
"Outside of a dog, a book is man's best friend. Inside of a dog it's too dark to read." Groucho Marx
http://www.hellophoenix.com/art/dreamhawaii.Cfm
Posts: 735
Threads: 20
Joined: May 2006
That urchin makes great bait for catching Uhu or parrot fish. The center part can be cut out and several of these can be placed on a hook. The rest can be crushed and thrown in the water to attract the Uhu.
Posts: 42
Threads: 5
Joined: Jul 2006
Why would anyone want to catch a poor parrot fish, they are just colorful to be looked at and photographed and not eaten. Why not try for some deep water good eating fish instead.
Always do what evers next.
Posts: 735
Threads: 20
Joined: May 2006
Many locals consider Uhu to be a good eating fish. I myself don't like to eat it because as you say, it's too colorful.
http://www.elmerguzman.com/recipes.php?recipe=40
http://www.geocities.com/TheTropics/Shor...-fish.html
