446 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



155 HAT€HINO LOBSTCRS IIV NORWAY.* 



By G. M. DAIVNEVIG. 



[Fiorn a letter to Prof. S. F. Baird.] 



If the question was as to whether it would pay to catch the lobsters 

 for hatching purposes, hatch the egg* artificially, and liberate the fry 

 immediately after hatching, I should answer that it would not pay, as 

 the lobsters themselves cau do the hatching much better than the best 

 of human inventions. If after the hatching we could rear them for at 

 least six weeks, then I think it would pay; for, although the losses in 

 the apparatus are heavy, I believe they would be still larger in nature. 

 But the immense number of eggs attached to the lobsters that are 

 brought to the market, which naturally would be destroyed, should be 

 hatched and the fry reared for a short time, if possible, as either hatch- 

 ing alone or hatching and raising is better than destruction. 



During the summer I have been experimenting here in hatching lob- 

 ster eggs. I began work in the latter part of Juue, and the first eggs 

 hatched on June 26. I have worked with only a small quantity of eggs, 

 as the question was rather to find the best methods for working on a 

 large scale next summer. By an accident to the supply-pipe only about 

 500 of the fry were left, but the possibility of the work was clearly 

 proved. The largest of the fry is now about nine weeks old ; they have 

 molted five times, and measure about 21 millimeters in length and 3 to 

 4 millimeters in breadth across the broadest part. They seem to be 

 healthy, and are very lively, and of greenish gray color. I still feed 

 them on the soft parts of crabs. 



I do not kill the lobsters, but simply get the spawn from the fisher- 

 men and exporters. I scrape it off with a small teaspoon, and very few 

 of the eggs are injured. They are rather heavy, and consequently I 

 give them a pretty strong current from underneath, just sufficient to 

 keep them slightly moving. I have used unfiltered water this summer, 

 but advise the use of filters, as the lobster eggs, being mostly in clusters, 

 are very apt to become covered by the impurities in the water. The 

 temperature in the water has been from 11° to 14° Beaumur, and the 

 specific gravity from 1.021 to 1.025. The time necessary for hatching 

 depends entirely on the state of the eggs when taken from the parent, 

 and the eggs from the same individual will not hatch at the same time, 

 but will differ as much as from three to four weeks. The apparatus used 

 is one invented by myself for the purpose, and is connected with the ap- 

 paratu -, used in hatching salt-water fishes. 



Flodevig, near Arendal, Norway, A ugust 26, 1885. 



For a previous letter on this subject see F. C. Bulletin, 1885, p. 280, 



