AQUARIUM OF MARINE LABORATORY, ABERDEEN 



23 



Figure 2. — Semipublic part of the aquarium. On the left are the large built-in display tanks illus- 

 trated in figure 1, Di to D^ ; De to D» can be seen through the door into the experimental aquar- 

 ium. Access to these aquariums is by a servicing platform behind the tanks. The center 

 tank is purely decorative. The small display tanks, di to ds, are on the right. 



within the limits normal for water in the 

 open sea. Incorporation of marble has 

 not resulted in any marked increase in the 

 calcium content of the sea water, which 

 is around 425 mg. per liter. 



Salinity has remained at around 34 

 parts per thousand and there has been no 

 occasion to compensate for evaporation. 



With few exceptions food is restricted 

 to squid cut to a suitable size and washed. 

 This food has the advantage of being firm, 

 and its use reduces to a minimum the wa- 

 ter-soluble and particulate matter which is 

 not taken up by the aquarium animals. 



Unvaried, it appears to afford a satisfac- 

 tory diet. 



Live material is transported in a carry- 

 ing tank designed to restrict violent move- 

 ments of water (fig. 3). Wlien the tank 

 is stocked for carrying, the domed cover 

 is secured in position, and water is added 

 to bring the surface level into the narrow 

 chimney. 



Each tank of the aquarium can be iso- 

 lated from circulation and in these cir- 

 cumstances is furnished with a small port- 

 able filter. Sea water is maintained in 

 circulation over this filter by means of an 

 air lift (see also Isolated Tanks, page 25). 



