36 



ing though harmless tentacles. Dogfish readily attack the 

 soft crawfish, however, as has been observed in the tanks, and 

 is evident from the fact that the soft shells of crawfish have 

 been found in the stomachs of these fish. The octopus also 

 is not deceived by the apparently unchanged shell. Even a 

 very small octopus has been observed in the tanks to attack 

 a large soft crawfish and secure one of the large legs, of which 

 it made a meal. Small crawfish also have been observed to 

 attack and demolish large soft crawfish. 



Apparently, however, man is the most serious enemy of the 

 crawfish in its adult stage, and this would be sufficient to 

 account for the rapid diminution in the supply, experienced 

 as the result of the extensive operations of the factories. 

 These adults occur in enormous numbers, and it was at first 

 supposed that no fishing operations could dangerously affect 

 the industiy, but the explanation at once of their large numbers 

 and the effect of fishing is probably to be found in the fact 

 that they have comparatively few enemies in the adult stage. 

 Another fact tends to confirm this, namely, that formerly, 

 before this extensive fishing, very large old crawfish were 

 frequently found, and these no longer or seldom occur in the 

 nets of the fishermen, though still readily procurable in fishing 

 grounds somewhat remote from those of the usual fishing 

 operations as, for instance, at Dassen Island. 



The following figures supplied by one of the Crawfish fac- 

 tories of the percentage of small and middle sized fish during 

 four years, 1909-1911. afford more definite evidence pointing in 

 the same direction : 35 per cent., 40 per cent., 40 per cent., 50 

 per cent. 



There are, however, other stages previous to the early ground 

 stage and the adult stage, as will be seen in the account of the 

 life history of the crawfish. The egg stage, when carried about 

 by the female, is not immune from hostile attacks. The eggs 

 are very carefully guarded by the female, and they may be 

 quite covered up by the strong flexure of the tail, but, from 

 observation in captivity, it was seen that several small fish, such 

 as Klip-fish, but particularly small Dasjes, are very fond of 

 the eggs and take every opportunity of harassing the female ; 

 darting under the tail, they frequently secure two or three, 

 and their success leads to repeated attempts. 



In some of the townettings made in Table Bay there was 

 found a considerable number of unhatched but well-advanced 

 eggs of crawfish. Whether or not this indicates that in nature 

 the eggs may be prematurely detached or, what is more likely, 

 that the females have been attacked for the sake of their eggs, 

 which are thus scattered about, is not yet known. The fact 



