RANDALL: SURVEY OF CIGUATERA AT MARSHALL ISLANDS 



toxicity would seem to indicate that it is only mar- 

 ginally a cause of ciguatera. 



Of two specimens from Enewetak, 356 and 364 

 mm SL, 1.8 kg, one was nonpoisonous and the 

 other toxic at level 1. 



Hiatt and Strasburg ( 1960) found benthic algae 

 in the stomachs of three of four specimens 

 examined in the Marshall Islands. Hobson (1974) 

 reported algae in three stomachs from Hawaii; 

 however, K. cinerascens apparently does not 

 occur in the Hawaiian Islands (though two other 

 species are present). 



Three specimens, 330-364 mm SL, from 

 Enewetak were opened. The stomach of one was 

 empty, and the other two contained benthic algae. 



Q 



The algae of one were identified by Tsuda as the 

 reds Gelidium pusillum, Champia parvula, and 

 Leveillea jungermannoids (90%) and the brown 

 Sphacelaria tribuloides. 



Carangidae (Jacks) 



Caranx ignobilis (Forsskal) (Figure 37): This 

 steep-headed jack is the largest species of the 

 genus. Bagnis et al. (1972) stated that it can attain 

 a length of 2 m and a weight of 80 kg. It can be 

 differentiated from other Marshall Islands species 



*Roy T. Tsuda, Marine Laboratory, University of Guam, Box 

 EK, Agana, Guam 96910, pers. commun. 1972. 



by the absence of scales on the thorax except for a 

 small median patch. Like other large carangids, it 

 is a roving carnivore; it may be encountered any- 

 where in the atoll environment including water 

 surprisingly shallow for such a large fish. 



The author interviewed a man and wife in 

 Moorea who were poisoned from eating the liver of 

 a large individual of this species (estimated 1.5 m) 

 which overturned their canoe in the long struggle 

 to catch it. Both were very ill with ciguatera, the 

 man comatose for several hours. 



Five specimens, 573-920 mm FL, 3.6-16.3 kg, 

 were obtained at Enewetak for the testing of toxic- 

 ity . Three gave a reaction and two a reaction of 1 . 

 Two specimens from Bikini, 635 and 1,105 mm FL, 

 4.5 and 27.3 kg, were nontoxic. 



A total of 14 specimens were collected for food- 

 habit study from the Marshall Islands, Line Is- 

 lands, Hawaiian Islands, Pitcairn Group, and the 

 Marquesas. Seven stomachs were empty, and the 

 rest contained the digested remains of fishes, of 

 which only one could be identified to species, the 

 surgeonfish Zebrasoma flauescens. One 

 stomach-content fish was a scorpaenid, and 

 another (from a jack of 1,217 mm FL, 37.5 kg) a 

 scar id. 



Caranx lugubris Poey (Figure 38): The black 

 jack is a circumtropical species with a well-earned 

 reputation for causing ciguatera. Although the 



Figure 31 .—Camnx ignobilis, 378 mm FL, Fanning Island, Line Islands. 



233 



