RANDALL: SURVEY OF CIGUATERA AT MARSHALL ISLANDS 



Figure 39.— Camnx melampygus, 498 mm FL, 1.9 kg, Sanganeb Atoll, Red Sea. 



Sixty-one specimens, 298-722 mm FL, from the 

 Marshall Islands, Hawaiian Islands, Line Islands, 

 Marcus Island, Solomon Islands, and the Red Sea 

 were collected for stomach-content study. Seven- 

 teen stomachs were empty. All the others con- 

 tained the digested remains of fishes, though one 

 had, in addition, a squid pen. The following fishes 

 were identified from the stomach material: eel, 

 Anthias thompsoni ,Caranx sp. (90 mm FL in a 520 

 mm C. melampygus), Priacanthus cruentatus, 

 Cirrhitops fasciatus ,Caesio sp.,Parupeneus sp.,P. 

 trifasciatus,Pomacentrus pavo, Chromis caerulea, 

 labrid, Thalassoma purpureum, Ptereleotris mi- 

 crolepis, Caracanthus unipinnus , Acanthurus tri- 

 ostegus, acronurus stage of acanthurids (in two 

 stomachs), and a subadult acanthurid. 



Caranx sexfasciatus Quoy and Gaimard (Figure 

 40): This jack, which ranges from the Red Sea to 

 eastern Oceania, is closely related to C. hippos of 

 the Atlantic. It is usually seen in small schools, 

 but is not common in the Marshall Islands. It is 

 more elongate than the Caranx spp. discussed 

 above, and it has a larger eye. The lower-limb gill 

 raker count is 15-17. The scutes are blackish, there 

 is a small black spot at the upper end of the gill 

 opening, and the soft dorsal and anal fins are 

 tipped with white. The dark bars of the young are 

 the basis for the specific name. 



Only two specimens were caught at Enewetak, 

 496 and 700 mm FL, 2.3 and 4.6 kg. Both were 

 nontoxic. No specimens were obtained from 

 Bikini. 



Ommanney in Wheeler and Ommanney (1953) 

 reported on the stomach contents of specimens 

 caught during a survey of the Mauritius- 

 Seychelles region. Eight specimens contained fish 

 remains, one had squid remains, one had 

 megalops larvae, and nine were empty. A par- 

 rotfish and two eels were noted among the stomach 

 contents. 



The stomachs of six specimens of C. sexfasciatus, 

 385-700 mm FL, from Enewetak and Tahiti were 

 opened. Five were empty, and one contained 

 well-digested fish remains. (This jack was speared 

 at 11:30 a.m.) 



Bagnis et al. ( 1972) stated that C. sexfasciatus is 

 nocturnal. Wheeler and Ommanney (1953) on the 

 other hand, wrote, "It often takes a lure..."; pre- 

 sumably he meant one trolled by day. 



Scombridae (Tunas) 



Gymnosarda unicolor (Riippell) (Figure 41): The 

 dogtooth tuna is named for its large conical teeth; 

 it is also unique in having two patches of villiform 

 teeth on the tongue. It lacks dark stripes or spots 

 on the body; the second dorsal and anal fins are 



235 



