HAMMERHEAD SHARKS — GILBERT 



45 



limits of its range in the eastern Atlantic are uncertain, although it 

 has never been recorded from the British Isles. 



Sphyrna lewini is found in the western Pacific from southern 

 Australia north to southern Japan and Korea, and in the eastern 

 Pacific from northwestern South America to the Gulf of California. 

 The fact that it is the only species of hammerhead definitely recorded 

 from the Hawaiian Islands (Gosline and Brock, 1960, p. 91) may 

 indicate that it is a more pelagic species than Sphyrna mokarran, 

 which also logically might be expected to occur there. 



r I 



mS\ 



mii^-iriAxAiyjzj 



Map 3. — Distribution of Sphyrna lewini. 

 (The most westerly record from Africa is now known to represent S. couardi; solid = 

 mens examined; hollo w= confirmed literature references.) 



:speci- 



Sphyrna lewini apparently does not extensively penetrate cool 

 waters (i.e., in which the temperature does not rise above the low 

 70's F.) . Although its range overlaps that of S. zygaena to some extent, 

 there are relatively few records of the two species having been taken 

 together (Herald, 1961, p. 31, fig.). 



Sphyrna (Sphyrna) couardi Cadenat 



Plates 9a, 10a 



Sphyrna couardi Cadenat, 1951, pp. 98-99. (Original description; compared with 

 S. diplana and S. bigelowi; tips of pectoral fins described as wliite; type 

 locality: "off West Africa".) 



Specimens examined. — -Guinea: USNM uncataloged (1 head, 425 

 mm. in width), 12°06' N, 17°22' W. 



Discussion — Sphyrna couardi was described by Cadenat (1951, 

 pp. 98-99) from "off West Africa." The description was very brief 

 and there was no illustration, although the form was said to resemble 

 S. diplana ( = S. lewini), differing from that species (and from all other 

 members of the family Sphyrnidae) in having the inferior part of the 

 pectoral fin white and a longer and smaller head. WhUe I have not 

 seen a whole specimen of S. couardi, I have examined a large head 

 (USNM uncatalogued) collected by Dr. Bruce B. CoUette from off 

 West Africa. This head, which is 425 mm. wide, has been compared 

 with the head of a typical specimen of S. lewini, 445 mm. wide (USNM 



