the rearing aprjarr.tus night he cleaned in the course of a quarter of 

 txn hotir for all floating particles - including old food and the 

 shells \vhich have been throvm off. 



The experience gained as to the iinportance of keeping the salt 

 water reservoir clean, and the ncthod vrorkcd cut for cleaning of the 

 apparatus are so valuable for the future vrork that they more than 

 compensate for the snail profit of one single year of experiments. 



In connectioa •■/ith the described :r/\ss occurrence of a "suctoric" 

 it may be nentior.ed that in the Ce nbra lblatt flir Bakteriologie, 

 Far as it enlcun de unji Infcld^on^la'£_iildieiter.i( Vol, T2, Jena"T9l4, there 

 is ail article by profl^ssor dr.* Reiner iMller about "Fischsterben bei 

 glcichzeitiger VorticellenvnAcherung auf den Daphnien des CTCTj-dssers''. 



In Septenber 1913 a mortality of fish occurred in t 6 hectares 

 large and 2,5 meters deep basin in Kiel. "Sting"-herrin£ and Bone 

 eels diede An invest ijj,at ion of the dead fish gave no inforrxition 

 about the cause of the death. ■'*t the sane tine a lot of snail 

 crrv;fish appeared in the Vv'ater, and these were quite over-grovm 

 Yri.th "vorticcller" (parasites?), up to 1000 on one individual. These 

 "vorticeller" are very similar to the "suctories"© The "vorticeller" 

 were not to be found en the dead fish - and the only explanation one 

 could give xrc.s that all the "vorticeller" had used the ox^'gen so 

 that the fish was stifled. 



It is, hoT/ever, impossible that the lack of oxygen should be 

 the cause of the death of the lobster* 



Danner>rigj Alf 



192Sb Hunneropdretningen 1927. Aarsberetning ved» Norges 



Fiskerier 1927 (1928), nr. 1, ppe 156-159 



The rearing cf lobs ters 1927 



In the .later years the results of the rearing of lobsters have 

 not been as good as one could wish, and as mentioned before, I have 

 had reason to believe thr.t this is due to lack of adequate food. 

 The earlier successful experiments were all made v;it]i crabs - but it 

 has been impossible to procvu'e these for several years. 



Yifhen the rearing experiments sttirted July 7 this year it v;as 

 therefore necessarj'- to try ot?ier and different food, and fortmiately 

 olready the "first experiment v;as successful. It appeared that fresh 

 ox liver \ms eaten with great appetite; it had .the adequate consis- 

 tency and vms easily distributed in the water without sinlcing. Fresh 

 ox liver could be bought all the tiiiie, and if kept in the refrigera- 

 tor it stayed fresh for more days. 



59 



