about an inch a year. Adults of 16-inch length 

 are approximately 16 years of age, the males at- 

 taining somewhat greater lengths than females. 



After juvenile stages are past, molts average 

 about 2i times per year, occurring most fre- 

 quently from March to July and from December 

 to February, at least in the Florida area. Among 

 captive animals, molts without growth can occur. 

 About 12 days elapse from the first sign of molt- 

 ing until the new exoskeleton is hard enough to 

 resist denting, though hardening of the new shell 

 is not complete until the 28th day. Travis ( 195-1, 

 1955a, 1955b, 1957) gave an exhaustive study of 

 the molting process among spiny lobsters near the 

 age of sexual maturity. This work is beyond the 

 scope of the present summary, but her findings 

 show that molting among captive adolescent ani- 

 mals is largely confined to the warmer months at 

 Bermuda and is more frequent than among Flor- 

 ida specimens. Other evidence shows that growth 

 of the young is more rapid in Bermuda than in 

 Florida, and that sexual maturity is reached 

 sooner. 



The mating season in Florida is principally 

 from Mai'ch through July. Sexual maturity is 

 reached in females as small as 6 inches long, but 

 ovigerous females under 8 inches in length are 

 rare. Mating pairs are judged to be about the 

 same age, and mating usually occurs in the hard- 

 shelled stage. At the time of mating the male 

 places a waxy spermatophore on the thoracic 

 sternum of the female. Prior to spawning, the 

 female scratches the surface of this packet with 

 the chelate fifth legs. The actual egg laying is 

 accomplished in about one-half hour, during 

 which the female lies partially on her back form- 

 ing a trough of the underside of her abdomen 

 with the aid of the exopods of the pleopods. Eggs 

 extruded from the oviducts pass backward from 

 the bases of the third legs over the spermatophore 

 and become attached to the endopods of the last 

 three pairs of pleopods. After spawning, the 

 spermatophore appears eroded as if enzymatic 

 action had partially destroyed it. The egsrs hatch 

 in about 1 month. A second mating and egg lay- 

 ing may ocur about a week after the hatch of the 

 first batch and at this time the ovary is spent and 

 the spermatophore almost completely eroded 

 away. Molting of females during this season oc- 

 curs only after spawning. 



The spawning season in Florida is principally 

 from March through June, and mostly in April. 

 However, a few ovigerous females occur as late 

 as October (December in the Bahamas). In 

 Puerto Rico, the spawning season may be more 

 extended than in Florida, for 22 percent of fe- 

 males in the commercial catch in Puerto Rico are 

 ovigerous in September and 18 percent in Octo- 

 ber. 



Direct evidence from the studies in Bermuda 

 shows that females may lay eggs twice in a season. 

 The number of eggs laid depends on the size of 

 the individual, and the second brood is smaller 

 than the first. Estimates show that a 9-inch fe- 

 male can lay 500,000 eggs, a 12-inch female 1,118,- 

 656, a 15-inch female 2,566,916. A second laying 

 by a 13-inch female consisted of 1,008,788 eggs. 

 Thus, it is estimated that a 15-inch female might 

 lay 4 million eggs a season. 



In Bermuda and elsewhere, there is apparently 

 a movement of females from shallow to intermedi- 

 ate depths and from deeper water to these depths 

 for spawning. Aside from these movements, there 

 is evidence in Bermuda that the lobsters exhibit 

 considerable homing tendencies, often moving as 

 much as 5 miles against strong tides to return to 

 the place of original capture. Adults tagged in 

 Florida, on the other hand, have moved as much 

 as 100 miles in 100 days (Smith, 1954), but such 

 movement is probably exceptional. 



The larva of the spiny lobster is a flattened, 

 leaf-shaped, planktonic organism which, before its 

 identity was known, was given the name phyllo- 

 soma. Development of the phyllosoma larvae of 

 P. argus has been studied off Florida and at other 

 points in the Atlantic Ocean from the West In- 

 dies to the southeastern coast of the United States 

 and north of Bermuda. Bigelow and Sears (1939) 

 found phyllosoma larvae (P. argus?) off Chinco- 

 teague Bay in July, 1929. Eleven stages have been 

 described from plankton. In Florida, the bulk of 

 freshly hatched larvae appear between June and 

 August, the last stages being taken in December 

 and January. The first postlarval, or puerulus, 

 stages appear in inshore waters from January to 

 March. Thus, larval development is judged to 

 require 6 months, and during that time the larvae 

 may be swept hundreds of miles from the spawn- 

 ing place. (Feliciano (1956) described a prenau- 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



93 



