228 THE CRAYFISH 



/Molting. — During the first year of its life the lobster molts from 

 fourteen to seventeen times. During this period it attains a length 

 of from two to three inches. Molting is accomplished in the follow- 

 ing manner : The carapace is raised up from the posterior end and 

 the body then withdrawn through the opening between it and the 

 abdomen. The most wonderful part of the process is the with- 

 drawal of the flesh of the large claws through the very small openings 

 which connect the limbs with the body. The blood is first with- 

 drawn from the appendage ; this leaves the flesh in a flabby con- 

 dition (a state similar to the taproot which has lost water by osmosis) 

 so that the muscles can be drawn through without injury. The 

 lobster also molts a part of the lining of the digestive tract as far 

 as the posterior portion of the stomach. Immediately after molt- 

 ing the lobster is in a helpless condition, and is more or less at the 

 mercy of its enemies until the new shell, which is secreted by the 

 skin, has grown. 



^Economic Importance. — The lobster is highly esteemed as 

 food, and is rapidly disappearing from our coasts as the result of 

 overfishing. Between twenty million and thirty miUion are yearly 

 taken on the North Atlantic coast. This means a value at present 

 prices of about $15,000,000. Laws have been enacted in New York 

 and other states against overfishing. Egg-carrying lobsters must 

 be returned to the water ; all smaller than six to ten and one half 

 inches in length (the law varies in different states) must be put 

 back; other restrictions are placed upon the taking of the 

 animals, in hope of saving the race from extinction. Some states 

 now hatch and care for the young for a period of time; the 

 United States Bureau of Fisheries is also doing much good work, 

 in hope of restocking to some extent the now almost depleted 

 waters. 



Shrimps. — Several other common crustaceans are near relatives of 

 the crayfish. Among them are the shrimps and prawns, thin-shelled, 

 active crustaceans common along our eastern coast. In spite of the fact 

 that they form a large part of the food supply of many marine animals, 

 especially fishes, they do not appear to be decreasing in numbers. Be- 



a far better chance of becoming adults than those left to grow up without protec- 

 tion. Later in hfe they sink to the bottom, and because of their protectively colored 

 shell and the habit of liiding under rocks and in burrows, they are comparatively 

 safe from the attack of enemies. 



