of the Fishery Board for Scotland. 



65 



IL_A CONTRIBUTION TO THE LIFE -HISTORY OF THE 

 LOBSTER (HOMARUS VULGARIS). By H. Chas. 

 Williamson, M.A., D.Sc, Marine Laboratory, Aberdeen. 



(Plates I.-IV.) 



CONTENTS. 



PAGE. 



Experiments in Lobster-Culture, .... 65 



The Rearing of Lobsters, ..... 68 



The Larval Stages, ...... 73 



History of the Adult Lobsters after the Eggs had Hatched, 87 



Proportion of Berried Hens in the Catch of Lobsters, . 88 



The Casting of the Lobster, ..... 89 



The Rate of Growth, ..... 95 



The Behaviour of the Lobster, .... 95 



Examination of the Ovary, ..... 98 



Spawning, . . . . . . . 100 



Hatching, ....... 103 



Literature, ....... 104 



Description of Plates, ..... 106 



Experiments in Lobster-Culture. 



In the summer of 1902 the Fishery Board instructed me to carry out 

 some experiments in the culture of lobsters and crabs. It was intended 

 that the young lobsters hatched out at the Laboratory should be liberated 

 on the north coast of Aberdeenshire, in the neighbourhood of Fraser- 

 burgh. In order to obtain a supply of larvae a number of berried hen 

 lobsters were procured from Girvan and Dunbar in June and July. 

 Eight were sent from Girvan and ten from Dunbar ; one was captured in 

 the Bay of Nigg. One of the Dunbar lobsters arrived on August 2nd. 

 The lobsters were conveyed by rail, packed, in some cases, in straw, in 

 other cases in dripping seaweed. The latter method was much the 

 better, the lobsters, after their eight to twelve hours' confinement, being 

 unpacked in a fresh and lively condition. Some of those packed in straw 

 succumbed. In 1904 the stock of berried lobsters were all packed in wet 

 seaweed, and none died in transit. 



No special apparatus, with the exception of two tin boxes, was made 

 for the experiment. A temporary arrangement of the hatching apparatus 

 (Dannevig's), used for the eggs of the plaice, proved successful on the 

 whole. The eggs were already far advanced. 



An attempt was made to hatch the eggs detached from the parent 

 lobster in one or two cases where the latter had died during transport to 

 Aberdeen. A sheet-iron box, which fitted into one of the compartments 

 of the hatching apparatus, and which was arranged with a perforated 

 bottom through which the water entered, to escape by the top of the box 

 through a grating, was employed ; but a considerable death-rate ensued, 

 and the eggs were attacked by a fungus. None of the eggs hatched out. 

 It was decided to allow the eggs to remain attached to the parent until 

 they hatched. All that was necessary then was to keep the adults in a 

 suitable tank and to make arrangements whereby the larvae, as they 

 hatched out, could be captured and removed to suitable boxes where they 

 would be under control. 



