of Rhode Island cooperated intensely vjlth the staijion at Yfickford. 



Vifith these results bofore us I believe that v;e T.-ny in full 

 confidence continue in tht direction v/e have taken. 



Hnrlingen, February 1921 



Advisor of Fisheries 

 Bo Havingn 



Havinga, B» 



1929 Krebse und Weichtiere. In Handbuch der Seefischerei 



':;.■ Nordeuropas, Gtuttgart, Br^nd 3, Heffc 2, 147 p., illus. 



.Crustacea and iiiollusca 



(p. 29) 



Lob ster 



r 



The larval habits -of life. The Ipbster larvae have, as riany 

 plankton organisms, considerably strong self loconotionj they use 

 this hoT/ever not for the attainment of a definite objective, but 

 .ajj-e activated by other stinuli as light, temperature, Y/ater, 

 ,; currents, etc* Thp ■ loconotion method is the sane in all three 

 :■:; -larval- stages; a similar rowing motion by means of the swimming 

 t IdiJibs -Q-f the thoracic feet and the last naxilliped appendages, 

 'vdaich, ^-re beset v/ith long feathery hairs. Besides, the larva can, 

 ftsxthe gra\'m lobster, m.ake quick baclr.Tardly directed motion 

 through- quick sr-"ps of the rear of the body. The rear of the body 

 •x'of the 2d and 3d stages plays a minor roll for sivitiming» The for- 

 ■ .\7ard motion is merely sIoy/, that to the rear consi'tlerrbly rapid, 

 but not to compare with the velocity which many other Crustacea 

 attain. For every pursuer, the larvae are easy prey; one can catch 

 , them easily v;ith the handj a fear instinct has not , developed. The 

 young 4th stage lobsters have an entirely other locomotion; they 

 can sv^-in an'-'' Viralk* Thev hold the bodj'' extended straight- for swim- 

 ming, also the claws are siturted in a straight line vrith the body 

 so they row themselves forvrard v/ith the rear bod.y feet. If they 

 ■^hen come in contact wit?i any object by means of the outstretched 

 claws, 'then they strike back quickly. >• 



The position and orientation ^f the larvae in -the water. The 

 larvae r£ the first three stages swim with bent bodies, the head 

 bends by a sloping angle dovmvrcrds r.nd the cephalothorax forms 

 vxith the rear of the body an angle of about .9.0 degrees. This posi- 

 tion they however not alv/ays : maintain, occasionally t?iey turn 

 thei:iselves around head foremost. Triey have no definite direction 

 when they are irritated. The circulation of the larvae in the vj-ater 

 is caused probr^bly for the great prjrt by the stinula^tion of light, 

 especially if they are held in pools. Information on their behavior 



143 



