NOTES ON THE BEHAVIOR OF SEA-ANEMONES. 1 



CHAS. W. HARGITT. 



During the summer of 1901 while keeping a few sea-anemones 

 in the aquarium for the purpose of studying their general habits, 

 particularly those of feeding, my attention was drawn to the 

 interesting phenomenon that certain species appeared more 

 alert during the night, closing up more or less during the 

 day. This was more noticeable in the large sand-anemone, 

 Eloactis proditcta, whose peculiar habit of burrowing in the sand, 

 enabled it to withdraw entirely when disturbed, or under other 

 unfavorable conditions. 



Having secured several specimens of this anemone they were 

 placed in an aquarium, the bottom of which had been covered with 

 sand to the depth of some six inches or more. The specimens, 

 true to their habit, soon burrowed deeply in the sand, and lining 

 the burrows with a slimy excretion they soon seemed quite at 

 home. During the day they would be found with only the whorl 

 of tentacles quietly protruding at the surface of the burrow, 

 where their colors so closely conformed to that of the sand that 

 the casual observer would hardly notice their presence. Going 

 into the laboratory at night I was interested to see the specimens 

 greatly extended, half of the body protruding beyond the bur- 

 rows and tentacles raised in an attitude to seize passing prey. 

 This was frequently observed afterward, and notes made of it at 

 the time were recorded in which it was remarked that " these 

 creatures are probably nocturnal in their habits." 



At the same time I had under observation another anemone, 

 Sagartia leucolena, a very common species about Woods Holl, 

 and it was seen to migrate at times into darker portions of the 

 aquarium, even creeping under bits of rock or other objects. 



No further observations were made on the subject till the cur- 

 rent summer. About a dozen specimens of Eloactis were col- 

 lected and placed in the aquarium as before, and with the same 



1 Contributions from the Zoological Laboratory, Syracuse University. 



274 



