informed by the lobster buyers that they have a relative large quan- 

 tity of spawn lobsters in stock in the spring, and we go there to 

 pick them out, it usually appears that the lobsters have lost a great 

 deal of the spawn. If the water is warm, this may happen because the 

 spawn has been hatched comparatively early, but at all events the 

 hatching. ..does .not take place until the midsuirmer time© 



In" 1936. v/e started purchasing by liiy 28 and continued until July 

 8; we had .then got a total .number of 649 spavm lobsters with eggs 

 ready for hatching. But the amount of eggs was very small on each 

 lobster. In the- hatching boxes where each lobster is by itself in a 

 small room v-rith sufficient renevral of the water j the lobsters have 

 no opportunity to fight and to scratch the spawn off each others 

 Yeja the oxiiount of spavra still decreases. This nay be ;due to the fact 

 that the spavm is infected vri.th a parasite, a "suctorie", Epholota 

 . gemipaj-a, v;hich can barely be seen with the naked eye. If a great 

 number of these develop, the eggs 'die,"and the lobster scratches 

 off the dead eggs, or they loosen by themselves c This parasite is 

 to be found everywhere in the beach region. I have' found it on nev/ly 

 caught lobsters, on beach crabs and on clams (mussels). But I have 

 never noticed that it plays any part as a destroying factor in 

 nature. I dare not say anything certain about this,, hbvever, but in 

 the hatchery, v/here v/e notice it all the tiiae during the summer, it 

 has on certain occasions appeared in such great quantities that it 

 has been an impediment to oiar \7ork with the lobster b-atching. 



That it appears to be so numerous here, v/as hard for me to under- 

 stand at first. But the first time I noticed this, heavy developiaent 

 during the summer 1926, it appeared that we hrd a source of infection 

 in the salt water reservoir from which the water was led to the lob- 

 ster apparatus, ^^fhen this soiirce of infection, namely a colony of 

 clams, had been removed and the reservoir had been scrubbed and washed, 

 conditions improved. After that time we ha\^e not used the salt water 

 reservoir for any experiiaent which could possibly contaminate the 

 vrater, but still vre had a new heavy development of the parasite dur- 

 ing the s\xr:aaer 1936. The salt water basin vjr.s once ;nore emptied and 

 scrubbed an4 conditions improved somewhat. But the essential part of 

 the young which were ?intched early in the season, died on account of 

 the infection. YJhen we remeriber that during, the rearing of Uie lob- 

 ster 300 cubic meters of water. per hour pas.s through our salt water 

 reservoir, vrhich is capable of about 2,000 cu. mtrs of v/ater, then 

 it is hard to understand that an infection -from the sides and the 

 bottom of the reserv-.ir, -which is overgrovm with comiion salt water 

 animals and seavreed, "could be the cause of a mass development of 

 parasites. It is. also a big question whether this same parasite is 

 the essential., cause v/hy the lobster loses its.spavm-in the lobster 

 storerooms. .The conditions there are very favorable for the 

 development o .'■ 



This parasite, vrhich attaches itself to all possible solid things, 

 feeds on the nutritive substances v/hich follow the current of v;ater. 



101 



