CRUSTACEA^ 

 STUDY OF LIVE CRAYFISH 



1. Collecting. 



(1) Day Field Trip. 



(a) Look along the edges of shallow ponds and streams. 



(b) Look under stones in the shallow rapids of small 



streams. 



(c) What means have the crayfish of evading or escap- 



ing you? 



(d) Where do you find the crayfish holes most numerous? 



(1) Note their depth. 



(2) Do the holes all have chimneys? 



(3) Did you ever find the chimney stopped up with 



mud? What kind of weather was it? 



(4) Do the crayfish live singly or in pairs? 



(2) Evening Field Trip. Try agpn at night, by placing 



a bright light where it will shine down into the 

 water. Crayfish will be attracted by the light and 

 may be captured with the net,^ which, for use in the 

 water, should be of strong, open-meshed goods like 

 seine cloth. 



(a) Do you find crayfish active in the daytime or at 

 night? 



(b) Are they solitary or gregarious? 



2. Aquarium. 



The habits and activities of crayfish may be advantageously 

 studied in a tank or any sort of an aquarium where the water 

 may be changed occasionally. 



(1) Do they seek the light or the sheltered places? 



(2) Find out, by trying various kinds of food, whether they 



are herbivorous, carnivorous, or omnivorous. 



(3) Watch them feed and describe their feeding habits. 



(4) Find out all their kinds of locomotion. 



(5) What means of concealment have they? 



1 The study of Insecta may precede that of Crustacea in order to obtain 

 live insects. 



2 See " Insect net." 



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