THE SPINY LOBSTER OF SOUTHERN FLORIDA. 301 



INFLUENCE OF TIDES. 



The influence of tides is not noticeable except where there are definite currents, 

 such as occur between the keys and reefs. Traps set in such places have shown repeatedly 

 that more spiny lobsters are taken when the tide is flowing out during the night and early 

 morning, or when the moon is in perigee, than when the tide rises during the night and 

 early morning, or when the moon is in apogee. It is thus possible to predict the relative 

 sizes of catches in a given place with considerable accuracy. This is the reason, no 

 doubt, for the belief among the fishermen that the moon influences the movements and 

 abundance of spiny lobsters. 



Traps set on the sides of a channel usually take more spiny lobsters than traps set 

 in the middle, which indicates that the lobsters avoid strong currents. 



MOLTING AND REGENERATION. 



No sharply defined season during which spiny lobsters molt could be determined, 

 since individuals of all sizes showing signs of molting can be found throughout the 

 year. From observation of a small number held in captivity the young are known to 

 molt more frequently than the adults, and it is supposed that females molt more regu- 

 larly than the males because they carry spawn. The males, however, attain a larger 

 size than the females, which probably indicates that their rate of growth is more rapid 

 and perhaps that they molt more frequently than the females. The time of the molting 

 season apparently varies somewhat from year to year, the variation being due probably 

 to the temperature of the water and to the abundance of food, both of which seem to 

 affect the rate of growth. 



Numerous males of medium size which were caught during February, 1919, had 

 recently molted or were in the process of molting. Larger males and females of small 

 and medium size molt during April, May, and June. Females which have carried spawn 

 molted in the summer from June to September or after the eggs had hatched. Several 

 large females caught in 1918 were observed to molt as late as October, but several large 

 males molted in the pounds as late as December. Several large females were observed 

 to molt three or four days after the eggs had hatched. 



PREPARATIONS FOR MOLTING. 



Spiny lobsters preparing to molt can be distinguished from the others by the dull 

 appearance of the shell, which is usually covered with fine silt and growths of seaweeds 

 and stalked diatoms. It has been observed among spiny lobsters in captivity that such 

 individuals seek sheltered places and remain inactive unless disturbed. Very little, if 

 any, food is taken by them. The second pair of legs is used to rub the eyes and anterior 

 parts of the carapace, and the fifth pair of legs frequently is used to rub the posterior 

 parts of the body. 



Hairlike lines appear about 80 hours before the shell is cast, one extending along 

 the branchial region of the carapace and another downward between the first and 

 second pairs of legs. These lines mark the places where the carapace will break and are 

 apparent only when molting is about to occur, although their places are marked after 

 molting by the regular arrangement of the tubercles. The lime salts of the shell are 

 gradually dissolved away along these lines until the shell is broken, and molting usually 

 occurs three or four hours afterward. 



