RANDALL: SURVEY OF CIGUATERA AT MARSHALL ISLANDS 



Figure 18.— Epinephelus microdon, 282 mm SL, Enewetak, Marshall Islands. 



ocean and lagoon reefs. As mentioned in the ac- 

 count of E. fuscoguttatus above, it has been con- 

 fused with this species by Schultz and other 

 authors. 



Thirty-nine specimens from Enewetak were 

 tested for ciguatera toxin. These ranged from 310 

 to 470 mm SL and weighed 1.4-3.1 kg. Eight were 

 nontoxic, 3 were toxic at the 1 level, 8 were 2, 13 

 were 3, 5 were 4, and 2 were 5 (caused death of test 

 animals). 



Nine specimens from Bikini, 279-508 mm SL, 

 0.9-4.1 kg, were tested. Two (279 and 342 mm) 

 were nontoxic, one was poisonous at the 1 level, 

 four were 2, one was 3, and one was 5 (460 mm 

 SL). 



Randall and Brock (1960) reported on the food 

 habits of this species (as E. fuscoguttatus) from 33 

 specimens taken in the Society Islands and 

 Tuamotu Archipelago. Of 10 with food in their 

 stomachs, 5 had eaten crustaceans (mainly crabs) 

 and 5 of them fishes. The eight specimens recorded 

 by Hiatt and Strasburg (1960) as E. fuscoguttatus 

 were probably E. microdon. Three fish had empty 

 stomachs and the remaining five contained fishes 

 and crustaceans. 



Helfrich et al. ( 1968) examined the stomachs of 

 150 specimens from the Line Islands of which 81 

 contained food, mainly fishes and crustaceans. 

 The latter accounted for 64% of the total by volume 

 (portunid crabs and scyllarid lobsters were the 

 most frequently recorded). A few of the groupers 

 had eaten gastropods and cephalopods. 



For the present food-habit study 44 specimens 

 (210-610 mm SL) were examined, of which 28 were 

 from Enewetak. The remaining 15 were from 

 Palmyra, Tutuila, and Rapa (where the largest 

 specimen was taken). Thirty of the 44 groupers 

 had empty stomachs. Eight contained crabs 

 (mainly porcellanids and portunids; one had eaten 

 the xanthid Carpilius conuexus), three contained 

 fishes (one identified as Scarus), two had eaten 

 octopus, and one a spiny lobster, Panulirus. 



Epinephelus socialis (Giinther) (Figure 19): This 

 grouper has numerous small dark brown spots 

 which tend to coalesce to form irregular longitudi- 

 nal bands, especially posteriorly. The caudal fin 

 and soft portions of the dorsal and anal fins have 

 narrow pale margins and broad blackish submar- 

 ginal zones. It is found mainly on the outer reef fiat 

 of the atoll environment, sometimes in surpris- 

 ingly shallow and often turbulent water. Al- 

 though fishes living entirely in this habitat would 

 not be expected to be ciguatoxic, Halstead and 

 Schall (1958) reported one specimen of this species 

 as weakly toxic from Maiden Island. 



Two specimens, 354 and 360 mm SL, 1.1 and 1.6 

 kg, from Enewetak were tested. Both proved to be 

 nontoxic. 



The stomach contents of seven specimens from 

 Enewetak, 235-360 mm SL, and one from Ducie 

 Atoll, Pitcaim Group (420 mm SL, 2.3 kg) were 

 examined. Three had eaten crabs (grapsids in two, 



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