CRUSTACEANS 



Fig. 132. — A female crayfish, showing the eggs 

 attached to her swimmerets. 



prone, while a milky glue gathering upon her abdomen was 

 stirred and whipped up with her swimmerets (Fig. 132). 

 Then she tipped her tail forward and her eggs gradually 

 poured out from the openings in the bases of her third pair 

 of walking legs onto the ventral side of her body which formed 

 a glue-lined basket. At the same time she rolled slowly from 

 side to side until all of the four or five hundred eggs were 

 firmly stuck to her swimmerets (Fig. 132). 



The young hatch in seven or eight weeks, usually about the 

 middle of Alay, but instead of dropping off into the water 

 each one takes firm hold of a maternal swimmeret with its 

 nippers and rides about on it for six or seven days. 



Aquarium study. — Crayfish can be kept for long periods in 

 aquaria properly supplied with a little mud and plenty of 



Fig. 133. — Common eastern crayfish, Cambarus 

 bartoni, showing the smooth shell of the carapace. 



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