The Inhabitants of the Aquarium 291 



low-bordered Water Beetle. It prefers 

 hunting near the bottom and between the 

 plants and the stones, to swimming in the 

 open water. While a slow swimmer, it is 

 an excellent flyer and can be found far away 

 from its usual haunts. It is rather scarce 

 in comparison with other varieties. Like 

 the others, the Black Water Beetle has to 

 come to the surface for its supply of air, 

 but in contrast to them it comes up head 

 first and uses its feelers or antennas to gather 

 the air and spread it over the lower side of 

 the body, where numerous very small hairs 

 hold it so that it envelops this part like a 

 layer of liquid silver. 



This beetle, on account of its slowness and 

 clumsiness, is not very dangerous to the 

 fauna of the aquarium, which can easily 

 escape from its attacks. Its prey consists 

 of smaller and slow-moving aquatic animals 

 and of fish eggs. If it happens to locate in 

 ponds devoted to the breeding of fancy fish, 

 it can do great damage, if not discovered 



