S.No. | Name of chemical | Purpose for which used | Remarks |
1 | Common salt (NaCl) | (a) | For dissolving sticky layer of cyprinid eggs | Clean kitchen salt is used for this purpose |
(b) | For bath treatment against external parasites | Industrial or coarse salt can be used |
2 | Carbamide [Urea: CO(NH2)2] | (a) | As main component of the solution for dissolving sticky layer of cyprinid eggs | Pure carbamide is used for this purpose |
(b) | For prolonging the viability of sperms and thus ensuring better rate of fertilization | Carbamide solution at a concentration of 3–4 g/litre |
(c) | As a fertilizer to increase plankton production in nursery and rearing tanks | |
3 | Tannin or Tannic acid | (a) | For dissolving the sticky layer of cyprinid eggs through denaturation of proteins | Extracted from the bark of certain trees |
(b) | As a bactericide and fungicide for fish eggs | This treatment causes the delaying of larval hatching considerably by hardening the egg shell |
(c) | For treatment of superficial wounds on brood fish, as a fungicide or disinfectant | Strong solution is required |
4 | Formalin (Formaldehyde) (CH2O) | (a) | For treatment against parasites, fungi, and bacteria | |
(b) | As disinfectant for cleaning hatchery tanks, equipment, and tools | |
5 | Malachite green | (a) | For treatment against external parasites, fungi, and bacteria | |
(b) | As disinfectant for cleaning hatchery tanks and tools | |
6 | Copper sulphate (CuSO4) | For treatment against all kinds of parasites and of branchial necrosis | Highly toxic. Should not exceed recommended concentrations |
7 | Copper oxychlorine (CuCl2 × CuO) | Used against unicellular parasites of small fish | Safe to use because of major difference between lethal doses for fish and parasites |
8 | Potassium permanganate (KMnO4) | (a) | Used against external parasites | |
(b) | As a disinfectant |
9 | Ethyl alcohol (C2H5OH) | As disinfectant for hypodermic syringes and injecting needles | |
10 | Absolute alcohol | For preserving pituitary glands | |
11 | Acetone (CH3 COCH3) | For preserving pituitary glands in dry condition (acetone-dried glands) | It dehydrates and defattens the glands |
12 | Quick lime or Calcium oxide (CaC) | For preventive treatment against harmful organisms | Usually used in the preparation of outdoor ponds for fry and fingerlings |
13 | Organic phosphoric acid esters | (a) | For use as “soft” insecticide against harmful aquatic insects and crustaceans | |
(b) | To promote the development of rotifers in fry nursing ponds | |
14 | Oxytetracycline (Terramycin) | (a) | For preventing and controlling bacterial diseases through bath treatment or by mixing in food | |
(b) | For preventing and controlling bacterial diseases in brood fish by injecting into body cavity | |
15 | Quinaldine or Chinaldin (2–4 methylchinolin) | (a) | As laboratory solvent | Toxic material; prolonged contact may kill the fish |
(b) | As tranquillizer |
16 | MS 222 | As tranquillizer | |
17 | Phenoxy ethanol | As tranquillizer | |
18 | Alkaline protease enzyme | For dissolving egg shells to facilitate hatching | |
19 | Fertilizers (Superphosphate, Ammonium nitrate, etc.) | For fertilizing nursery and rearing ponds | |