RANDALL: SURVEY OF CIGUATERA AT MARSHALL ISLANDS 



Labridae (Wrasses) 



Cheilinus undulatus Riippell (Figure 42): The 

 giant humphead wrasse is one of the largest of 

 bony fishes. It has been recorded to a length of 2.29 

 m and a weight of 190.5 kg (Marshall 1964). The 

 hump on the forehead develops only on larger in- 

 dividuals. Two dark lines which extend pos- 

 teriorly from the eye are useful in identifying 

 juveniles and subadults of this species. It is usu- 

 ally found on outer reef slopes or in deep channels, 

 but also occurs in lagoons. It is difficult to ap- 

 proach underwater. According to Bagnis et al. 

 (1972) individual fish have a home cave to which 

 they retreat when threatened and to which they 

 retire at night. Randall (1958) reported this 

 species as capable of being moderately to strongly 

 toxic in Tahiti, where it is called "mara" (Randall 

 1972). It is one of nine species of fishes which are 

 banned from sale in the Papeete market (Bagnis 

 1968). 



Seven specimens, 515-995 mm SL, the largest 

 weighing 34.5 kg, were procured at Enewetak for 

 testing. The largest gave a reaction of 2 on feeding 

 to mongooses; the others were 0. 



Randall et al. (1978) reported on the food habits 

 of the giant humphead wrasse based on the 

 examination of 72 specimens from the Red Sea and 

 islands of Oceania. The diet is highly varied, the 

 dominant groups of food organisms being mol- 



lusks (gastropods a little more numerous than 

 pelecypods), crustaceans (especially crabs), 

 echinoids, and fishes. The hard parts of the inver- 

 tebrates are crushed to fragments by the powerful 

 pharyngeal dentition. 



Coris aygula Lacepede (Figure 43): This is one of 

 the two largest species oi Coris (the other an unde- 

 scribed endemic from Lord Howe Island). The 

 largest collected, from the Red Sea, measured 465 

 mm SL and 583 mm TL. Adult males develop a 

 gibbosity on the forehead similar to that of 

 Cheilinus undulatus, but these two wrasses could 

 hardly be confused; the Coris is more elongate 

 (depth about 3.2 in SL) and has small scales (60-65 

 lateral line scales for C. aygula, compared with 

 about 25 for Cheilinus undulatus); also, the lateral 

 line of Cheilinus is interrupted. 



Coris aygula has apparently not been reported 

 as causing ciguatera but because of its large size 

 and similar food habits it would seem to be at least 

 as suspect as C. gaimard which is known to be 

 poisonous at times. The latter is more colorful, 

 displaying bright blue spots and a yellow caudal 

 fin. 



Five adults of C. aygula, 329-377 mm SL (0.9-1.9 

 kg), were obtained from Enewetak for testing. One 

 of 368 mm SL ( 1 .4 kg) produced a toxic reaction of 1 

 when its liver and viscera were fed to a mongoose; 

 the others were nontoxic. 



Figure 42.— Cheilinus undulatus, 915 mm SL, 25.8 kg, Enewetak, Marshall Islands. 



237 



