Biomineralization

“Biomineralization is the process by which mineral crystals are deposited in an organized fashion in the matrix (either cellular or extracellular) of living organisms” (Boskey, 1998).

The mineral requirements in fish appear to be very complicated since metabolism and nutrition of minerals are closely related not only to those present in the diet but also to those dissolved in the surrounding water. Recently, however, it has been reported that dietary minerals have enormous effects on growth, survival and malformation in carp, Chinook salmon, eel, channel catfish, red sea bream and yellow-tail. Addition of the salt-mixture at dietary levels of 4 to 5 % was found to be optimal for growth and prevention of deformity in both species when casein was used as the sole dietary protein.

With the exception of the organically bound elements hydrogen, carbon, nitrogen and oxygen, there are about 20 or so inorganic mineral elements which are considered to be essential to animal life, including fish. The essential mineral elements are usually classified into two main groups according to their concentration in the animal body; the microelements and the microelements as given below:

The essential mineral elements 1
Macroelements		Trace or microelements
Principal cations	Principal anions
Calcium (Ca)	Phosphorus (P)	Iron (Fe)	Fluorine (F)
Magnesium (Mg)	Chlorine (Cl)	Zinc (Zn)	Vanadium (V)
Sodium (Na)	Sulphur (S)	Manganese (Mn)	Chromium (Cr)
Potassium (K)		Copper (Cu)	Molybdenum (Mo)
		Iodine (I)	Selenium (Se)
		Cobalt (Co)	Tin (Sn)
		Nickel (Ni)	Silicon (Si)

¹ Underwood (1971); Reinhold (1975)
Minerals are required for the normal life processes, and all animals, including fish, need these inorganic elements. Fish may derive these minerals from the diet and also from ambient water. The minerals are responsible for skeletal formation, maintenance of colloidal systems, regulation of acid-base equilibrium and for biologically important compounds such as hormones and enzymes.

Mineral deficiencies can cause biochemical, structural and functional pathologies which depend on several factors, including the duration and degree of mineral deprivation.