240 "PERFECT-MOUTHED" FISHES 



clothed with overlapping cycloid scales, sometimes very small and 

 completely embedded in the skin ; the fins are long and narrow or 

 leaf-shaped, and the fin rays are not bony, but consist of out- 

 growths of the skin ; the jaws are furnished with strong crushing 

 plates. 



The African Mud-fish (Protopterus annectans) frequents marshes 

 by the riverside in Central Africa. It is a large and peculiar-looking 

 creature, with a long, eel-like body, having small cycloid scales 

 embedded in the skin, and sometimes attains a length of 6 feet. 

 Its food consists chiefly of frogs, insects, worms, and crustaceans, 

 and it is said sometimes to attack and bite its own kind, particu- 

 larly if several are enclosed in the same aquarium. During the 

 day the mud-fish is sluggish ; at night it becomes more active 

 and moves about over the mud at the bottom of the shallow water 

 on its paired fins, which it uses after the manner of legs, or swims 

 rapidly by powerful strokes of its tail. It is said to be in the 

 habit of rising to the surface at short intervals to take in fresh 

 supplies of air; 



During the dry season, when the marshes become dried up, 

 the mud-fish buries itself in the mud and hibernates until the 

 return of the rain, forming a sort of nest or hollow chamber about 

 18 inches beneath the surface. It remains in a state of torpidity 

 for about six months, from August to December, and when the 

 marshes are once more flooded comes forth in a perfectly healthy 

 condition; 



The eggs of the mud-fish are deposited in a rough kind of nest, 

 which is merely a hole on the edge of the swamp in the midst of 

 long grass. The eggs rest on the mud, in the water, and the male 

 fish mounts guard and continuously lashes the water with his 

 tail to keep a well-aerated current passing over them. 



