MARINE AQUARIA 



Freshwater aquaria are familiar household objects, but the Marine 

 aquarium is known to the general public only through the exhibitions at 

 World's fairs or those in some of the larger cities, as in Castle Garden, 

 Battery Park, New York; the Vivarium of the University of Pennsylvania, 

 at Philadelphia; and the Grotto of the Fish Commission Building, at 

 Washington, D. C. 



It is a general opinion that the marine aquarium is difficult to estab- 

 lish in the household, though it is really easier to maintain, when properly 

 installed, than those of freshwater, as ventilation, good light and sunshine 

 are not as important; they are even to some extent objectionable, as strong 

 light is likely to produce an excessive growth of algae, and oscillatoria, 

 which may cause turbidity in the water, and the marine fauna is more 

 comfortable without much light, as in the ocean they obtain comparatively 

 little. 



Aeration. The necessary aeration is not produced by the growth 

 of plants, as is the case in the freshwater aquarium. The marine flora 

 cannot be kept in fine growing condition under any circumstances, and 

 may be largely dispensed with, its purpose being more to enhance the 

 beauty and add to the natural appearance of the aquarium than to serve 

 as oxygenators. The all-important necessity is an efficient artificial aera- 

 tion, and some little experimentation is necessary that the introduced air 

 is evenly distributed at all times, and In sufficient quantity to satisfy the 

 requirements of the animals without excess and overstimulation. The 

 correct amount under varying conditions is soon learned. The air should 

 be admitted along the rear of the aquarium as a heavy fog, not in small 

 bubbles to burst on the surface. More air must be Introduced when the 

 water Is warm than when it Is cold, as at higher temperatures less Is ab- 

 sorbed by the water, while the animal requirements are greater, they 

 being then the most active. 



The simplest and most efficient aerating device is the cylinder and 

 pump described on page 178; and which should be kept In constant opera- 

 tion, though care should be taken not to over-aerate the water. 



Another simpler aerating device consists of a flowerpot or jardlnaire, 

 having the bottom hole plugged with a piece of sponge and suspended 

 over or supported on the frame of the aquarium. Into this some of the 

 water is filled and in perculating through the sponge Is both cleared and 

 aerated. It fully answers the purpose for shallow smaller tanks. 



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