No. 634] UTILIZATION OF ECHINODERMS 419 



reducing the number of starfish in regions where shell-fish 

 live, as various forms of starfish feed on marketable shell- 

 fish. Lebour (1916) makes an interesting statement: 



important of these is the starfish, Asterias rubens, which constantly 

 preys upon them. A formerly flourishing bed near the Tyne has lately 

 been exterminated by this starfish and it is a bad enemy everywhere. 

 Purpura lapillus [a small gasteropod] devours the mussels on the scaup, 

 Holy Island, and here in parts the devastation caused by this small and 

 very destructive mollusk is great. It does not, however, appear to be a 

 scourge elsewhere. The only possible way of dealing with such foes 

 would be to destroy all starfish whenever found, and to collect the Pur- 

 pura lapillus systematically, and also its spawn, and destroy both. 



Kellogg (1910) records nothing favorable about the star- 

 fish. To him it is a pest. 



The removal of these pests has always been a very difficult matter, and 

 no entirely satisfactory method has been devised for accomplishing it. 



When the economic value of starfish is realized, depletion 

 of starfish may result from overfishing, and 1 i to destroy 

 all starfish whenever found" will be out of the question. 

 If it prove necessary to protect starfish, where only the 

 gonads are to be used, these may be removed on the 

 grounds, while fishing, and the starfish at once put back 

 into the water below low-tide level to avoid unnecessary 

 exposure. The operation of removing the gonads could 

 be carried out successfully without killing the animal, 

 since echinoderms possess great regenerative powers. 

 As male gonads may be unfit for caviar, it is worth noting 

 that they can be easily distinguished from the female 

 since the latter are of pinkish color while the former are 

 of light yellowish hue. The reproductive power, and 

 growth of starfish, are very great. According to Kellogg, 

 "A female starfish may, if large enough [depending on 

 amount of foodl begin to extrude eggs during its second 

 summer, and many by that time attain the required size." 



As echinoderms, on the north Pacific coast, can be more 

 easily caught than any other kind of sea food, the star- 

 fish and some of the sea cucumbers may simply be picked 



