194 Dwellers of the Sea and Shore 



one-lialf inches long and it has antenna? that equal 

 it in length. Its legs are remarkably slender and 

 fragile and seem almost too delicate to support even 

 so buoyant a body as the prawn's appears to be; the 

 animal is, nevertheless, a good crawler and gets its 

 food by this means, either on the bottom or on the 

 fronds of seaweeds. 



As a matter of fact, all prawns, though capable 

 swimmers and given to migration, are sedentary in 

 their habits, and the majority of species, like many 

 other sedentary animals, are protectively camouflaged. 

 They may be uniformly colored in sundry shades of 

 red, brown, or green, or they may be marked by various 

 patterns of color. These varicolored individuals are 

 usually found among seaweeds which they closely re- 

 semble : the blotched and the barred forms, for instance, 

 are frequenters of the larger and coarser weeds, and 

 the lined forms live among the finely branched and 

 feathery growths. There is evidence that these dif- 

 ferent color patterns may be acquired during the 

 growth of the animal; that is, a young prawn reared 

 among finely branched seaweeds will become lined, 

 while another kept in a tank containing coarse vege- 

 tation will in time acquire bars or blotches. Even adult 

 specimens have been observed to change their color 

 after a few days when placed among plants of a dif- 

 ferent hue, their pattern, however, remaining the 

 same. But here is something still more peculiar : if one 

 of these prawns be put into a white dish, or if kept in 

 the dark, it becomes nearly colorless, and it does so 

 within a very short time. This it accomplishes by a 

 contraction of its pigment cells, or chromatophores, the 



