LOBSTER, CRAB, AND SHRIMP 26T 



large as the period at the end of this sentence. No 

 one has yet counted the number of eggs in the 

 average sponge, as the egg mass of the female crab 

 is called, but the number has been variously esti- 

 mated as between 1,750,000 and 4,500,000. After 

 being attached to the fine hairs of the swimmerets 

 on the under side of the abdomen of the mother for 

 about two weeks, the little eggs hatch. The mortality 

 of the 3^oung crabs must be very high, for if all the 

 crabs hatched in one season grew to maturity, they 

 would crowd all of the water out of the Chesapeake 

 Bay. 



The life history of the crab resembles in many 

 respects that of the lobster. The growth proceeds in 

 stages, taking place immediately after each molt, 

 just as in the case of the lobster. The growth of the 

 crab, however, takes place much more rapidly than 

 that of the lobster. Immediately after the first molt, 

 the young crab increases in length more than two 

 hundred per cent. From then on its growth is some- 

 what less rapid, as its average increase in width from 

 one stage to another is only thirty-two per cent. At 

 the age of one year, when about fifteen moltings have 

 occurred, the crab reaches maturity and does not 

 molt again. By this time, the crab is about six inches 

 in width. Individual male specimens are found which 

 are somewhat larger than this, sometimes attaining 

 a width of eight and a half inches and a weight of 

 one and a quarter pounds. Females seldom exceed 

 seven inches in width. 



Young crabs also resemble lobsters and many other 

 crustaceans in possessing the power of regenerating 



