BULLETIN OF THE UNITED STATES FISH COMMISSION. 27 



tensive lobster lisbery iu the world. Tliey appear to be much less com- 

 mon in Xewfoundlaud and Labrador, possibly because they bave been 

 less fishetl lor there. 



Lobsters are not known to migrate, excepting over very short dis- 

 tances, mainly in the spring and fall, when they change their grounds, 

 moving into deeper water on the approach of cold weather, and return- 

 ing nearer to the shore in the late spring. The fall migrations are 

 solely for the purpose of escaping the cold of winter, the shallower sum- 

 mer grounds probably furnishing a better supply of food. The extent 

 of the movements depends more or less upon the character of the coast, 

 for where the bottom slopes off very gradually they will need to go a 

 much greater distance to reach a suitable depth of water than where 

 deep holes occur near their summer grounds. The summer fishery is 

 mainly in depths of a very few to 15 or 20 fathoms, the winter fishery 

 in 25 to GO fathoms. On the coast of Maine the traps are sometimes 

 set iu such shallow water that they lie partly exposed at low tide. For- 

 merly some fishing was done along the shores by means of gaffs and 

 dip-nets, but lobsters rarely occur in such favorable localities now. 



It is supposed that lobsters do not travel much along the coast, though 

 they probably change their grounds from time to time in search of food. 

 On some portions of the coast the fishermen claim to have good evi- 

 dence of the schooling of lobsters, and state that the schools appear 

 and disappear suddenly, indicating the possession of certain migratory 

 habits, but there is no proof that their migrations extend far, and they 

 are very different in character from those of the true fishes. We have 

 no evidence to prove that any one region has been directly benefited by 

 large accessions from an adjoining region, and the extent to which some 

 districts have been depleted by overfishing without subsequent recovery 

 indicates that the supplies of one region are but little dependent upon 

 those of another, at least not for immediate relief. The Cape Cod lob- 

 ster fishery has been at a low standing for many years, and although 

 but few men have engaged in the fishery of that region for a long time, 

 there are, as yet, no signs of improvement. 



SPAWNING SEASON AND HABITS, DEVELOPMENT AND RATE OF 



GROWTH. 



Lobsters are found with spawn attached to the abdomen during the 

 entire year. This fact is recorded of both the American and the Euro- 

 pean species, but the length of time they are carried before hatching 

 and the limits of the hatching season are not precisely known. As re- 

 gards the European crayfish, a freshwater crustacean closely related 

 to the lobster Professor Huxley states: "The process of development 

 is very slow, as it occupies the whole winter. In late springtime or 

 early summer, the young burst the thin shell of the egg, and, when they 

 are hatched, present a general resemblance to their parents. This is 

 very unlike what takes place in crabs and lobsters, in which the young 



