Appell/f, Dr. A, '■'" 



1909 Untersuchungen Uber den hrumaer, Bergens Mus» Slcrifter, 

 Wy rc>.elcke, bd. 1, no« 1, 79 p«, illus. 



(page 39) , 



The grovrbh d u ring the f irst grovirbb ' periods I mentioned above 

 briefly, under th'e charr.oteristics of the various larval stages, 

 the groTirth rates. Already in these stages one notices individual 

 differences as much in relation to the duration of the. various 

 stages as also in the magnitude .of their grovrbh. In an earlier 

 publication (3) 1 indicated closer boundaries ^^ithin \Thich the 

 duration 'of the various stages fluctuates and these data can only 

 be completed by later experiments. During the rearing experiments 

 vdiich I made in the mid^dle of the nineties at the local Biological 

 Station, l' found in relation to the dui'ation of the various stages 

 the following fig\jrese The first stage lasted normally 6-7 days, 

 it could hovrever extend e^-en to 8-9 days; the, second normally 9-10 

 days, a minimian of 7 and a maxiravuii of 12 days; the third normally 

 10 days, yet probably also individual differences occijrred hereo 

 In regard to. the foijrth stage I could only vrorlc on tvj-o individuals 

 at that time. One of these spent 23, the other 28 days in this 

 stage. Yet, as vms mentioned earlier this last stage can no longer 

 be considered as belonging to the larval life but is to be regarded 

 as the first lobster stage. 



'• Already in 1892, hovrever, Dannevig (2) had made experiments at 



the'Pl/devigen fish hatchery which showed that grovrbh and casting 

 of the larvae were dependent to a high degree on the temperature of 

 the sea vmter, a fact that vras further clarified and confirmed later 

 by the experiments of other, workers* Dannevig proved that dijiring the 

 couTse of nine days at a temperature of 8-10° Co no casting occurs 

 among the larvae of the first stage at a temperature of 12 C, they 

 cast once, at 16-22° C, they had in this time also passed through 

 the second larval stage and entered into the third. Although those 

 experiments were made only with a smallvJlumil-^er of individuals and 

 consequently give no information concerning possible individual vari- 

 ations and their extent they are hov/evqr , of interest as they prove 

 ■ directly the influence that temperature, exerts on the metabolism of 

 the larvae and thus on their groviitho 



1 had occasion in my experiments at Kvittings/ that were made 

 in boxes v/hich floated on the surface to follOT" the Lioultings and 

 grovjth of a large number of ioi:stor young from the , first larval 

 stage to the end of the first groi-.th period. The shortest time 

 which I observed for the duration of the first larval stage vra,s 4-5 

 days, instead of the usual 6-7 clays. The, shortest period of tim.e I 

 observed at the end of July 1903 v;hen. the temperature on the surface 

 rose to 14° Ro (17.5° C.). It lasted .however only during the first 

 tv/o days of the development of the larvae and then sank to 11° R. 

 (13.8° C.)j a pair of very warn days are therefore sufficient to 

 accelerate the development. The shortest time for the second stage 



