FIELD BOOK OF PONDS AND STREAMS 



Copepods — Copepoda 



There is scarcely a pond to be found without copepods. The 

 Httle water-hoppers of the genus Cyclops, the commonest of all 

 entomostracans, are in every pond and ditch which offers 

 them a semblance of habitation. To the naked eye Cyclops is 

 only a little white speck jerking through the water. It has a 

 pear-shaped body tapering into a forked tail, a pair of long an- 

 tennae, outspread like antlers and helping it to skip through 

 the water, a single eye in the middle of its head, and four pairs 

 of swimming-feet on the thorax. If it is a female Cyclops 

 the pair of egg-packets hanging from her sides will be visible 

 as far as the animal can be seen. The copepods are very uni- 

 form in their general shape and habits and Cyclops is typical 

 of them all (Fig. 126). 



Fig. 126. — A water-fiea, Cyclops; female carrying 

 a pair of egg packets. 



When they are mating the male Cyclops clasps the female 

 with his antenna and they swim about together for long 

 periods during which enough sperm cells to fertilize several 

 clutches of eggs are transferred to the body of the female. 

 Like other entomostracans, they produce two kinds of eggs — 

 summer ones which form in rapid succession and develop 



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