30 Marine Invertebrates 



table 4. Artificial seawater (according to McClendon) . 



(All solutions are of M/i concentrations unless otherwise stated.) 



NaCl 483.65 cc. NaoSiOa 0.0025 gm. 



KC1 10.23 cc. NaoSuOo 0.003 cc. 



MgS0 4 28.55 cc. H 3 P0 4 0.002 cc. 



MgClo 25.16 cc. H3BO3 100 cc. 



CaClo 1 1 .00 cc. AloCl,; 0.01 cc. 



NaBr 0.8 cc. NH 3 0.001 cc. 



NaHC0 3 2.5 cc. LiN0 3 0.002 cc. 



H 2 373-63 ". 



It is claimed that even most delicate marine algae will live in this solu- 

 tion for long periods. 



For marine forms Penn (1934) recommends the use of the following 

 medium which is based for anions on the analysis of the salt content of 

 the blood of certain organisms and for cations on the buffering properties 

 of salts. 



table 5. Perm's medium for marine forms. 



NaCl 0.1335 N 



CaClo 0.0112 N 



KC1 0.0084 N 



NaN0 3 °-°°55 N 



NaHC0 3 °°48 N 



MgS0 4 .' 0.0040 N 



KH2PO4 000 °5 N 



NaSi0 3 trace 



NH4NO3 (For green forms only) 0.0125 N 



FeCl 3 (For green forms only) trace 



Artificial seawater is regularly used by several marine aquaria in 

 Europe. For example, water in the Berlin aquarium consists primarily 

 of an artificially prepared solution mixed with a small amount of natural 

 seawater. For making up the large quantities of artificial seawater 

 needed for the operation of a public aquarium, a simple procedure must 

 be followed and no attempts made to add all the salts entering into 

 the composition of natural water or to use chemically pure ingredients. 



table 6. Von Flack's formula for making large quantities of 



artificial seawater. 



Sodium chloride (NaCl) 2815 gm 



Calcium sulphate (CaS0 4 2H2O) 172 gm 



Magnesium sulphate (MgS0 4 7H2O) 320 gm 



Magnesium chloride (MgCb 6H2O) 850 gm 



Potassium chloride (KC1) 80 gm 



Magnesium bromide (MgBr2) 10 gm 



Water 100 liters 



