a giant clam list - Hippopus and Tridacna

[rgulrich]

A post from one of our fellow reef keepers from the Middle East got me to thinking about an article I'd read a few years ago on the discovery, or re-discovery, of a giant clam in the Red Sea that had been thought to be extinct "“ the T. costata. That said, and a little bit of data mining later, I came across the following list of current (you'll see why I say "current" a bit later) giant clam species out there and thought it might be a good thing to post for everyone's enjoyment and reference.

If you have a few spare moments, it may be worth your while to do some online searches for these, both common and uncommon clams. This may help you identify that next clam purchase and determine its care requirements before you bring it home. It would be great to have a collection of research papers referenced on these as well.

Oh, and a search for images - while not always entirely accurate - does provide some interesting photos of some of the more rare species as well. Try Tridacna mbalavuana for a starter.

Here we go:

"¢ Hippopus (genus)
o Hippopus hippopus - Hippopus Clam, Horse's Hoof clam .
(H. hippopus also known as Bear Paw Clam and Strawberry Clam)
o Hippopus porcellanus - China Clam

"¢ Tridacna (genus)
o Tridacna crocea - Crocea Clam, Crocea
(T. crocea is also known as the Boring Clam, Boring Giant Clam, Crocus Clam, and Saffron-Colored Giant Clam)
o Tridacna derasa - Derasa Clam
o Tridacna gigas - Giant Clam
o Tridacna maxima - Maxima Clam, Maxima
o Tridacna squamosa - Squamosa Clam
o Tridacna mbalavuana Ladd - Tevoro Clam
(Syn: Tridacna tevoroa)
o Tridacna costata. This species of giant clam is very new discovery. It was first reported and described as a new living species in 2008 by Roa-Quiaoit, Kochzius, Jantzen, Zibdah, and Richter. This giant clam has a small population, is highly endangered, and not found in the aquarium industry. (search "œTridacna Costata AND may have fed early humans" for some interesting reading)

o A tenth species, Tridacna rosewateri, isn't being generally accepted because it was described only from shells found in an isolated region in the Indian Ocean

Oh, and if any of our fellow reef keepers visiting the Indian Ocean and may have happened across a living T. rosewateri and taken a photograph, it sure would be nice to see it here!

 

[kfisc]

Good post; T. costata and T. mbalavuana were especially edifying to learn about.

 

[rgulrich]

Some useful Tridacnid research/articles:

As the title indicates, the distribution of giant clams (and a wealth of other information).
THE DISTRIBUTION AND STATUS OF GIANT CLAMS (FAMILY TRIDACNIDAE) – A SHORT REVIEW
Othman, Goh and Todd
from THE RAFFLES BULLETIN OF ZOOLOGY, 2010, 58(1): 103–111, Date of Publication: 28 Feb.2010
© National University of Singapore
http://rmbr.nus.edu.sg/rbz/biblio/58/58rbz103-111.pdf

Analysis and classification of materials collected in 1895-98 and retained in the Mollusca collection of the Natural History Museum in Vienna as T. squamosina, and identical to T. costata.
Tridacna (Chametrachea) costata Roa-Quiaoit, Kochzius, Jantzen, Al-Zibdah & Richter from the Red Sea, a junior synonym of Tridacna squamosina Sturany, 1899 (Bivalvia, Tridacnidae)
from Ann. Naturhist. Mus. Wien, B, 112, 153-162, Wien, März 2011
Huber and Eschner
http://www.landesmuseum.at/pdf_frei_remote/ANNA_112B_0153-0162.pdf

Comparative analysis of T. squamosa spawning methods used in Makogai, Fiji.
Comparative Study of Available Spawning Methods of the Giant Clam Tridacna squamosa [Bivalvia: Tridacnidae] in Makogai, Fiji
Navneel and Azam
School of Marine Studies, The University of the South Pacific, Private Mail Bag, Laucala Campus, Suva, Fiji
from World Journal of Fish and Marine Sciences 5 (3): 353-357, 2013
ISSN 2078-4589
©IDOSI Publications, 2013
DOI: 10.5829/idosi.wjfms.2013.05.03.72164
http://www.idosi.org/wjfms/wjfms5(3)13/20.pdf

Status of Giant Clams in Singapore and relationship to conservation efforts. Interesting mention of use of substratum (…Tridacna maxima, as they partially burrow into coral heads for anchorage…). Some good color plates
CONSERVATION STATUS REASSESSMENT OF GIANT CLAMS (MOLLUSCA: BIVALVIA: TRIDACNINAE) IN SINGAPORE
Neo and Todd
Experimental Marine Ecology Laboratory, Department of Biological Sciences, National University of Singapore
14 Science Drive 4, Singapore 11757, Republic of Singapore
From NATURE IN SINGAPORE 2013 6: 125–133, Date of Publication: 25 June 2013
National University of Singapore
http://rmbr.nus.edu.sg/nis/bulletin2013/2013nis125-133.pdf

 

[maroun.c]

Thanks for the info Rgulrich.
Its a sad fact though that clams and other corals from the Red Sea are beeing taken out by reefers or lfs employees that have licensed (or sometimes not)access to pull things out from Specific areas. I'm guessing some rare clams could have been taken out and never were ID'd. I am in contact with many LFS owners and staff in countries on the Red Sea, will try to share the info with them. I'm hoping they will educate their staff to avoid having endangered species collected. Will try to gather as many Identification example to share with them as they usually snorkel and pull clams off so theyll need to be very familiar with the clams Id to know the rare ones in a quick dive...
We also setup a small forum for reefers in the middle east so i'll share the info there as well, hoping people will have knowledge about local clams offered for sale. We have some divers on the forum as well so I'll ask them to photograph any interesting clams in the area and share here.

 

[rgulrich]

That's great to hear, Maroun. I wish I could snorkel in the Red Sea and Arabian Gulf-there is a lot of very unique life in those two areas. Please keep us up to date on your information campaign in the region. I understand the difference in collection practices in the region, and think you have some work ahead of you to change some minds there.

If you need any more research drop me a note, and I'll see what I can dig up.