Why Do Clams Die in Aquariums?

Our beautiful new 222-page ebook, SAVING GIANTS: Cultivation and Conservation of Tridacnid Clams (by Gerald Heslinga, 2013) is now available for download http://store.blurb.com/ebooks/374835-... [or go to blurb.com and search for SAVING GIANTS]

References: https://docs.google.com/document/d/1n...

Why do Tridacnid clams sometimes die unexpectedly in aquariums? Much of the mortality of
giant clams in captivity relates to the size of the byssal gape on the underside of the clam.

The blue clams Tridacna maxima and T. crocea burrow into coral heads and attach tightly to the coral with strong byssal threads. When harvested in the wild, these clams have a large, unprotected byssal gape which can allow an entry point for predators and parasites. Because the byssal threads grow out of the foot of the clam, cutting the byssal threads at harvest may damage the foot. This internal injury will not be outwardly visible but it may lead to declining health and death of the clam weeks or months after its harvest.

The larger, non-blue clams including T. derasa and Hippopus hippopus live unattached on the substrate and have very narrow byssal gapes. They can close their shells tightly to keep out parasites and predators including snails, crabs and some types of dangerous fireworms. Moreover, there is a much lower probability of damage to the foot of these species when they are harvested.

Hippopus hippopus has a thick shell and zipper-like shell margins. It is the most predator- and parasite-resistant of the giant clams in mariculture operations and probably in aquariums as well.

Watch more videos in our giant clam educational series:
http://www.youtube.com/user/GeraldHes...

Read Joseph Rosewater's classic monograph on the family Tridacnidae in the Indo-Pacific:
https://docs.google.com/fileview?id=0...

Read the classic Aquaculture article on Cymatium snail predation on giant clams by Perron, Heslinga and Fagolimul:
https://docs.google.com/fileview?id=0...

Learn more about predatory fireworms:
   • Good Worms vs Bad Worms  

[Videography and narration by Gerald Heslinga of Indo-Pacific Sea Farms (www.ipsf.com). Thanks to Steve Lindsay for 3 Kosrae Tridacna sp. images in the credits segment. Song credit: Mark Knopfler, What it Is.]

Further reading:

https://docs.google.com/document/d/1n...