308 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1947 



in a favorable place for throwing the spear the moment a big ray 

 was approached. Standing poised, a man cast the spear into the head 

 of a big fellow. The pole came oiit of the spear point, and was hauled 

 aboard by the attached line. The tiller rope unwound from the float- 

 ing drum as the ray soimded. Then, for nearly half an hour, the big 

 manta tired itself out on the floating buoy. Finally, it was killed by 

 rifle fire. 



This harmless ray measured 9 feet 8 inches across and took 8 men to 

 haul it up on the deck of the boat. It has at the front of its head, 

 on each side, a long fleshy cephalic lobe, used to direct a current of 

 water into its big, almost toothless mouth. This pair of lobes resembles 

 the wings of the trawl and served the same purpose. Within the 

 mouth, along the sides, are very fine-meshed gill rakers, serving to 

 strain the planktonic organisms from the sea water that passes in 

 the mouth and out the gill openings. The stomach of this big ray 

 contained a few quarts of larval crustaceans. 



Another group of fishes, the sharks, attracted attention. Although 

 several kinds were encountered, such as tiger, bullhead, and whaler 

 sharks, the most common were black-tipped, white-tipped (fins), and 

 the gray shark. The latter species, not exceeding 7 feet in length, 

 outnumbered all the others. 



One night in Boro Passage, a picket boat was anchored for the 

 purpose of catching sharks. Tuna fish caught that day by trolling 

 along the outer reef and through the passages were passed through 

 a small sausage grinder, and the chopped up meat and blood was 

 cast slowly into the channel waters that were flowing outward. Within 

 a short time, sharks were chummed to the boat by the presence of 

 blood in the water. Then chunks of tuna meat, the size of a man's 

 fist, were thrown into the water and others placed on big steel hooks. 



The gray sharks struck these baited hooks with greed and speed. 

 They jumped from the water. Several would rush the bait and each 

 other as they fed voraciously. At the end of a few hours, 29 sharks 

 measuring from 3 to 7 feet had been successfully landed on the boat. 



USE OF BOTENONE IN COLLECTING KEEF AND LAGOON FISHES 



Methods of collecting fishes at Bikini included baited hook and 

 line, trolling, spearing, dredgmg, attracting them to a surface light 

 at night, and the use of various nets. The most important was the 

 use of powdered plant roots to stupefy fishes, and since our methods 

 of using it on coral reefs are unpublished, they are herein described. 

 Powdered cub^ or derris root with 5 percent of rotenone content has 

 been used by various ichthyologists for nearly 40 years to collect fishes 

 for scientific purposes. Dr. Carl H. Eigenmann, during field work 

 in South America in 1908, probably was the first ichthyologist to 



