2 9 6 BULLETIN OP THE BUREAU OF FISHERIES. 



upon which the external genital organs are located press against the posterior margin 

 of the sternum of the female, and the little brushes which are located on the anterior 

 sides of the external sexual organs of the male are in such a position that the backward 

 flow and escape of the seminal fluid would be prevented. It seems, therefore, that 

 the seminal vesicle is formed between the sterna and that its shape is determined by 

 the depressions. 



HABITS AND MOVEMENTS. 



HABITS. 



The spiny lobster is nocturnal in its habits and remains hidden during the day 

 under shelving rocks, large sponges, or other growths offering protection. Spiny 

 lobsters may be detected in such places by the protruding antenna: or forepart of the 

 body. Feeding evidently occurs at night while they are crawling about, and most of 

 those taken by the fishermen are caught at this time. 



Spiny lobsters are observed frequently crawling about in trains, the antennse of 

 one in contact with the body of the one in front. These trains probably constitute 

 the so-called schools reported at times. Several small individuals are seen usually 

 under the same sponge or rock, and numbers of them often crowd together in a small 

 space. They seem to be gregarious, it being well known among the fishermen that 

 where one spiny lobster is seen there may be several more close at hand. 



The spiny lobster in captivity tends to avoid the light, and the character of its 

 natural habitat is indicated by its habits. The best fishing grounds are found where 

 plenty of cover is available, such places being rocky bottoms, coral heads and reefs, 

 places where sponges are growing, or where artificial shelter has been provided acci- 

 dentally. There is no evidence that the spiny lobster burrows into muddy banks or 

 inhabits muddy bottoms. None was taken with traps set repeatedly in such places, 

 while better success .was attained with traps set on rocky bottoms or where sea fans 

 were plentiful. 



MOVEMENTS. 



It is generally believed that the spiny lobster is rather sluggish in its movements. 

 The usual method of locomotion is crawling slowly but nimbly about on the tips of the 

 claws, but movements can be made to either side or backward with considerable rapidity. 

 The most powerful movements are accomplished by flexures of the pleon or tail, but no 

 great distance is covered in this way between rests. Short distances are covered rapidly 

 sometimes by swimming on the side, or even on the back. Swimming is used principally 

 in escaping from enemies and is not often employed in going from place to place while 

 feeding. There is no reason to believe, however, that the range is restricted to a small 

 area. Considerable distances could be covered by crawling, and it does not seem 

 probable that the spiny lobster actually returns to the same shelter except by accident. 



HABITS IN CAPTIVITY. 



Spiny lobsters upon being impounded crawl about the inclosure and seek a sheltered 

 place away from the direct rays of the sun. The antennae are carried above the ground 

 while the spiny lobster is crawling about, and if there is sufficient room they are spread 

 out on either side. They are thrust forward or switched up and down when an enemy 

 approaches. The tail is flexed under the body usually while the animal crawls slowly 



