110 GOLDFISH VARIETIES AND 
MARINE AQUARIA 
The maintenance of a marine aquarium is really much simpler than 
is generally supposed. If aquarium lovers realized the great charm and 
the unlimited possibilities of a marine tank, there can be no doubt many 
more would interest themselves in this particular form of the hobby. It 
is safe to say that not a score of persons in America at this time have 
saltwater aquaria, although when once established they are as easily kept 
as the freshwater kinds. Then, too, there is the fascination of collecting 
from a field of inexhaustible variety, giving the student always something 
new to work on, with the ever-present possibility of discovering some fact 
of value to science or to his fellow aquarist. To those living within easy 
journey to the shore is the added attraction of the trip to the seaside, the 
pleasures of which are doubled by the pursuit of such a delightful and 
absorbing study. 
Aeration. There are just a few points of radical difference between 
the fresh and saltwater aquaria. We have carefully pointed out the oxy- 
genating value of aquatic plants, and shown how their work is necessary 
to a “balanced,” or reciprocating aquarium. This factor must be left out 
of consideration in the saltwater aquarium, for marine plants perform 
this function to so small a degree as to become unimportant. The Ulva, 
or Sea Lettuce is the most satisfactory of the easily obtained plants. It 
has been known to do well for quite long periods. A few bits of cork 
placed beneath will cause it to float to the top, where it looks and does 
best, at the same time shading the water. The beautiful Actiniz, or Sea 
Anemonies, which are flower-formed animals, present a bewildering array 
of form and color far surpassing any freshwater plants. These were 
once supposed to form a connecting link between the animal and vegetable 
worlds, but this is an error, the beautiful creatures belonging purely to the 
animal kingdom. Other attached animals also make up for the lack of 
vegetable life as far as appearance is concerned. 
For the lack of oxygen from plants we have either to depend upon 
mechanical processes, or to substantially reduce our number of aquarium 
inmates. The surface of the water takes up enough oxygen to maintain 
a few animals, but if our ideas are more ambitious it will be best to install 
an air pump such as described on page 10. This will more than com- 
pensate for any plant deficiency, especially if the air is liberated in very 
small bubbles. In the case of large maine aquaria where the water is 
constantly pumped out, filtered and returned, the oxygenating is accom- 
