54 PRACTICAL CARP CULTURE. 



pond and over the water plants searching for food. They will make three 

 meals a day on fish eggs, if they can find them, and lunch frequently be- 

 tween meals on the same dainty. 



THE WATER FLEA (enlarged.) THE WATER ASELL (enlarged.) 



THE WATER FLEA. 



(Gamarus pulex.) 



Known as flea crab, buck crab, etc., is another voracious enemy of the 

 crustacean tribe. It is closely related to the shrimp found in the ocean 

 It has a curved back, as shown in the illustration, and lies on its side 

 while burrowing through the water. In all stages of its life it feeds upon 

 fish eggs. It makes some return, however, by becoming itself an excel- 

 lent morsel of food for young fish. 



THE COMMON POND SNAIL, 



(Lymnea fragilis.) 



Which consumes large numbers of them, and is too well known to need 

 any description. 



THE BOAT FLY, 



(Notonecta glanca.) 



Commonly known as the "Shoemaker" is a most voracious insect and 

 very destructive of young fish. The following description of it, together 

 with the descriptions of the dragon fly and its larVa; the yellow banded 

 water beetle and its larva and the black water beetle are all taken from 

 Hugo Murlertt's excellent work on Goldfish and its Culture. 



The body of the boat fly is long, contracted posteriorly, convex above 

 and flat below, having hair at the sides and extremeties, which, when 

 spread out, supports the insect upon the water. The head is large and 

 presents a large eye upon each side, giving the possessor the power of 

 vision in all directions. The color of the body is a greenish grey, the 

 wings are white, of the legs, the four nearest the head are short, but the 

 third pair are very long, different in shape from the others, very much 

 resembling boat oars. When in the water, the insect swims upon its back, 

 using the hind legs as oars for propulsion, while the front ones are instru- 

 mental in seizing its prey. Young fish, tad-poles, and other insects, all 

 contribute to supply it with food, to the former, especially, it is a very 



