electrical control equipment, and storage 

 cabinets . 



A smaller area in an enclosed platform 

 over the headbox (fig. 3) provides for 

 tanks and experimental apparatus to be set 

 up for work in convenient isolation. Elec- 

 trical outlets and water taps are located 

 along the rear wall. The enclosed platform 

 was also designed to serve as an observa- 

 tion platform with an overall view of the 

 main tcink (fig. 6), and for that reason the 

 side facing the tank has a 36- inch high 

 wall and has curtains handing from above. 



Flexibility is maintained in the same 

 manner as in the main tank; the wing room 

 and enclosed platform have no permanently 

 installed equipment, but each piece is set 

 in position when needed. Small pieces of 

 E^paratus which require a catch basin for 

 splash or a temperature-maintaining bath 

 can be set up in the large teink or one of 

 the smaller ones. 



Special equipment 



The varied nature of the research in 

 this laboratory requires special constructed 

 equipment as well as converted military sur- 



plus and staindard commercial apparatus. 



Tests investigating the responses of 

 fish to an electrical field (fig. 7) re- 

 quire an electric generator and electronic 

 pulse-control units. The generator and 

 one set of controls are located on the 

 machinery deck over the sump. A second 

 control unit is located in the wing room. 



Studies of fish behavior in the daurk 

 or in very low light intensities are aided 

 by military-type infrared viewers and 

 lamps. Infrared illumination (figs. 8 cind 

 9) permits observations without disturbing 

 the behavior of the fish (Duncan 1956). 



Experiments which require close con- 

 trol of water temperature are conducted in 

 the wing room where heat-exchange coils 

 can be set in the tanks. These coils are 

 a part of a custom-built heat-exchange 

 unit that provides heating or cooling as 

 desired with a regulation of ^ 0.1° C. 

 The unit will maintain any preselected 

 temperature from 0° to 25° C. , and it has 

 a heating rate of 2.1° C. per hour, a cool- 

 ing rate of 1.5° C. per hour as currently 

 used with the 300-gallon experimental 

 system shown in figure 10 (page 6). 



Figure 8. — Interior view of the enclosed platform over 

 headbox. Mounted on tripod are infrared lamp and 

 viewer used for observing fish in darkened tanks. 



