Content of tahong shells

Answer 1

the major content comprising the shell of Perna viridis (the green lipped mussel or Asian green mussel) is no different than any other bivalve mollusk.

Most of it is built out of calcium carbonate. The outer layer, or periostracum is mostly protein, basically an organic skin over the top of the shell (which gives the shell colour, and lays down the calcium carbonate to keep the shell growing).

In addition to the calcium carbonate, there are trace minerals which are laid down in the shell. These trace minerals are gathered from the environment, and are rarely really intended to be in the shell, but are more or less impurities and contaminations in the content of the shell. Because these elements get laid down in the shell, the accumulation of them in the shell can be an indication of contamination in the environments that the bivalve was living in.

Minerals such as lead, cadmium and zinc, or organophosphate pesticides and petroleum byproducts are easily detected in the shells, and make critters like Perna viridis useful as biological monitors of the health of an ecosystem.

Testing the mineral content of their shells gives an indication not just of current conditions, but of the long term conditions and contaminations in a site. None of these minerals are major components of the shell - often being measured in the parts per billion - but are valuable for marine ecological studies.

Answer 2

Tahong shells are composed mainly of calcium carbonate, which makes up the hard outer shell. They also contain small amounts of protein, lipids, and other minerals. These shells are often discarded after the meat inside is consumed, but they can be ground into a powder and used in various applications such as as a calcium supplement or soil additive.