454 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
does not, in its range, overlap that of the true lobster, nor compete with the latter in 
any of our markets. On the Pacific coast the spiny lobster is coufined to the south- 
ward of Point Conception, which to some exteut marks the dividing line between a 
warmer and a colder fauna. The same influences (temperature mainly) which thus 
restrict the range of Panulirtis to the south of Point Conception would limit the dis- 
tribution of the true lobster to the north of the same point, providing its introduction on 
the Pacific coast was attended with success. There would be no more conflict between 
the two species than now occurs on the Atlantic side, but the same condition of affairs 
would be expected to exist. The comparison may perhaps be strengthened by imag- 
ining the extinction of the true lobster on the coasts of the Middle and New England 
States and the British Provinces. Its place could scarcely be filled by the Southern 
species. 
Admitting the expediency of stockiug the Pacific coast with lobsters, the ques- 
tion of their adaptability to that region next requires investigation. The North 
Atlantic aud North Pacific Oceans have much in common with respect both to their 
physical and their biological characteristics. Identical species of fishes and marine 
invertebrates inhabit the northern parts of both oceans, and the number of related 
forms in the two regions is very great. The natural resorts of lobsters on the eastern 
coast, rocky, gravelly, and sandy bottoms, covered in places with kelp and rock- weed, 
aud with an abundance of aquatic life suitable for food, occur throughout the North 
Pacific region from California to Alaska. Temperature, however, is probably to be 
regarded as the most important factor determining the fitness of the region for this 
new food product, and it is the only one which we can now pretend to measure 
although we have little data respecting it for the western coast. 
On the Atlantic coast the lobster ranges from Delaware to Labrador, being most 
abundant between the Cape Cod region of Massachusetts and the Gulf of St. Law- 
rence and Newfoundland. Its bathymetrical distribution is from the littoral zone (in 
some localities) to depths of probably 50 and 60 fathoms, but the fishery is chiefly car- 
ried on inside of a depth of 30 fathoms. It apparently does not migrate up and down 
the coast to an appreciable exteut, but moves off into deeper water with the approach 
of winter in order to escape the severe cold. 
The continuous temperature observations in the possession of the Fish Commission 
relate mainly to the surface waters, but in the shallow areas where they were taken 
there is generally not much difference in this respect between the surface and the bot- 
tom. Delaware Breakwater, practically the southern point in the range of the Amer- 
ican lobster, which occurs here only in small numbers, is located between the light- 
ships at Winter Quarter Shoal, Virginia, and Five Fathom Bank, New Jersey, the 
distance between these light ships being about 56 miles. At the former the annual 
range of water temperature is from 35° to 76° Fahr., at the latter 37° to 76°, there 
being practically no difference between the two.* Above Five Fathom Bank light- 
ship, on the New Jersey coast, lobsters become somewhat more abundant on several 
off-shore banks, the range of temperature at Sandy Hook light-ship, just to the north 
of these banks, being from 33° to 74° Fahr. In Long Island Sound, where several 
important fishing localities exist, the range, as determined at Bartlett’s Eeef and 
Stratford Shoal light ships, is from about 33° to 70° Fahr. The middle portion of Vine- 
*111 all of these records the observations for January, February, and the first part of March are 
omitted. 
