36 



THE AQUAEIUM, APEIL, 1896. 



able hue. The female is smaller in 

 size, and not quite so brilliantly colored. 



The entire body of the paradise fish, 

 from the mouth to the beginning of the 

 caudal fin, is covered with small round 

 scales. 



Their mode of living, when compared 

 to American fishes, resembles that of 

 the little dog fish (Umbra Crameri) and 

 the rainbow-darter (Poecilichthys coe- 

 ruleus). Like the former, they come 

 to. the surface of the water for atmos- 

 pheric air, and owing to this faculty 

 Avill live and thrive in a remarkably 

 small quantity of water. They are also 

 fully as inquisitive as the dog fish, and 

 like to stay near the glass side of the 

 aquarium, and observe what is going on 

 outside of the water. Like the rain- 

 bow-darter, they are fond of resting on 

 rocks, or on the branches of water 

 plants. In fact, we have frequently 

 seen them lie down as a person would on 

 a lounge, their head upright and their 

 body resting sideways on the bottom. 

 They are graceful swimmers and peace- 

 able, agreeing well with other fishes, 

 except during their breeding season, 

 when they must be kept by themselves. 

 Their food is the same as that used for 

 goldfish, but it should be given to them 

 oftener. Being tropical fish, they are 

 rather sensitive to cold, and the water 

 in which they are kept should never be 

 below 55° F, while 70° to 90° is their 

 favorite temperature. 



We were the first to imj^ort these in- 

 teresting fish to this country, and, 

 breeding them in the parlor aquarium 

 are enabled to add to the above descrip- 

 tion of the fish our observations regard- 

 ing their mode of reproduction. 



The paradise fish is a nest builder, to 

 a certain extent. Its nest is not as 

 complicated as that of the stickleback, 

 nevertheless it is a receptacle on which 



it places the eggs to be hatched. As 

 soon as the warm weather approaches 

 the males commence fighting with each 

 other for the possession of the females. 

 The victor leads off his female to a 

 suitable corner in the aquarium, and 

 here their family life begins. The nest 

 is constructed by the male. In building- 

 it he takes a position about an inch be- _^ 

 low the surface of the water, and fre- 

 quently takes air into his mouth, which 

 he ejects in the shape of little bubbles. 

 These bubbles seem to be covered with 

 some viscid substance, which makes 

 them last for several hours. He keeps 

 this up until a little floating island is 

 formed of about six inches in circumfer- 

 ence and one-fourth of an inch in thick- 

 ness. When the nest has reached the 

 sufficient size, the female approaches 

 and swims around him several times 

 until he notices her. He follows her 

 now around in a circle, immediately 

 under the bubble island, and all at 

 once, with a very graceful motion, he 

 seizes her by folding his entire body 

 and fins around her, at the same time 

 turning himself, with her, over in the 

 middle of the water, so that the ventral 

 parts point towards the nest. Now he 

 presses against her and causes the eggs 

 to flow, which in passing him become 

 fertilized and rise to the surface. This 

 act being over, the male's attention is 

 occupied by gathering the eggs with 

 his mouth and placing them on top of 

 the bubble-island. Should one acci- 

 dentally fall to the bottom, he carries it 

 up again immediately. When all the 

 eggs are cared foi-, the female makes 

 her appearance again, and repeats the 

 operation until about a hundred eggs 

 are laid. The eggs are of the size of 

 a period used in ordinary type, and of 

 creamy-yellow color. Thirty-six hours 

 after the eggs are laid, the young fish 



