EXPERIMENTAL EMBRYOLOGY OF FISH 



THE CARE AND FEEDING OF FISH 



"The water In a flah tank need never te changed if the conditions are perfectly 

 balanced." Follovring is a discussion of the environmental variahlea that must he taken 

 into consideration in the breeding of fish. 



SIZE OF TANK : 



This depends upon whether the fish are to be raised in colonies; whether they are 

 large or small, active or sluggish; whether they are sociable; and whether the adults eat 

 their eggs or their young. In general the shape should be rectangular, with the depth and 

 breadth the same and the length twice as great. The most satisfactory size is 85- x &|- x l6 

 inches (supplied in quantity by Metal Frame Aquaria Company, West Caldwell, N. J.). Such 

 a tank may be used for colonies of Oryzlas, Paradise, or Platys, which represent egg-layers, 

 bubble-next builders, and live-bearers. This size tank may also be partitioned off for a 

 Betta breeding tank. Larger tanks will be necessary for Hemlchromus or the large mouth- 

 breeders. The fast-moving Zebras require a long and narrow tank, measuring *+ x ^^ x 2'4- 

 lnches. 



STEUCTLTRE OF TSE TAMK : 



Except for the frame, the tank should have walls of glass and bottom of slate. None 

 of the frame should come in contact with the contained water. A glass cover should be 

 provided, which will keep out all dust. A comer of this glass plate may be removed in 

 order to facilitate the Introduction of the daily food ration. The edge of the glass 

 plate may be protected by adhesive tape. 



REPAIR OF THE TANK : 



When a leak occurs it will be necessary to remove the glass plate on that side, eo 

 least. Occasionally all the glass plates should be removed eind the entire frame cleaned. 

 This is a tedious performance but a little extra care will reduce the neceeslty for repe- 

 titions. 



Remove the glass plates in the proper order. When the bottom Is glass, it is the 

 first to be removed since it was the last to be put in place. Soften the cememt which 

 holds the glass in place by means of a cup of cleaning fluid (Dri-Kleen), and remove the 

 cement and wedge out the glass with a putty knife. Remember that the glass is brittle. 

 Thoroughly clean the frame and glass before replacing the parts, and cement with regular 

 aqueirium cement. 



It is virtually impossible to cover a leak with aquarium cement and to have it hold. 

 Even the slightest leak should be remedied by complete removal of the faulty plate. After 

 a repair Job, run water through- the tank for several days. 



CLEANING TEE TANK : 



Even a new tank should be treated with dilute KMNOj^ solution for at least 2k hours 

 before use, and an old tank may occasionally require a complete cleaning. In such cases 

 a thorough washing with soap and water, a soaking with dilute KMNOii, and a 2'+-hour rins- 

 ing are in order. 



Some fish are naturally dirtier than others (e.g., Hemlchromus, Tulapla) and it will 

 be necessary to siphon off the faecal material and unlngested food almost dally. If aera- 

 tors are used, they must be shut off and the debris allowed to settle for a time before 

 siphoning. If the aerators themselves become clogged with debris eind vegetation they 

 should be removed and cleaned by dipping them in acetic acid or vinegar, and rinsing. 



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