5 2 Memoir Sears Foundation for Marine Research 



Developmental Stages. The Guitarfishes are ovoviviparous,^^ and it has long been 

 known that the inner walls of the uterus in gravid females are thrown into a series of 

 thin longitudinal folds. 



Habits. They swim slowly near the bottom, or they lie half buried in the sand 

 or mud. We read that in Australian waters "they can be easily approached and picked 

 up by the tail."^" When swimming, the muscular tail is used as the organ of propul- 

 sion, the pectoral fins to raise or lower the body or to turn and bank. Their food seems 

 to consist mainly of small fishes or of crustaceans, shellfish, and other ground-living 

 animals, which they crush with their small rounded teeth. Some of the Indian Guitar- 

 fishes are said to live in large schools and to do great damage to the pearl oyster beds 

 of Ceylon and elsewhere. ^^ 



Relation to Man. In Peru, Guitarfishes are eaten extensively by the poorer people, 

 mostly dried or salted, but they are regarded as mediocre in quality. ^^ A few are also 

 exposed for sale in tropical fish markets in other parts of the world, some are taken 

 to rendering plants in California, while in India the fins of a few are prepared for export 

 to China, where they are used for soup, as Shark fins are. They are not of interest to 

 anglers and are entirely harmless to bathers. 



Range. Tropical and warm temperate coastal waters of all oceans, running up into 

 fresh water locally and even breeding there. ^^ Eastern Atlantic northward to Portugal 

 and the Mediterranean; southward along northwestern and tropical western Africa, 

 at least to southern Benguela (recorded from Mossamedes, about Lat. i6° S).^* Western 

 Atlantic from North Carolina to Uruguay and northern Argentina.^^ Pacific Coast of 

 the Americas from middle California (San Francisco) to Peru. Western Pacific from 

 mid-China (Shanghai), Japan, and Korea to Queensland, Australia, in about Lat. 23— 

 24° S; Philippines; Malayan region as a whole; south along West Australia to about 

 Lat. 25° S (Sharks Bay); coasts of the Indian Ocean from Bay of Bengal, Arabian Sea, 

 Gulf of Oman, Red Sea, and along the coast of Africa to Natal and to the Cape of Good 

 Hope (Table Bay). 



Species. Twenty-six species oi Rhinobatos are recognized in the most recent synopsis 

 of the genus^^ and four more have been described subsequently as new.'' But the 



29. See Southwell and Prashad (Rec. Indian Mus., j6, 1919: pi- 18, figs. 1-4) for illustrations of early embryos prior 

 to the fusion of the anterior parts of the pectorals with the head; see Ranzi (Publ. Staz. Zool. Napoli, jj, 1934: 

 365) for a recent account, with photograph, of the uterine wall. 



30. Whitley, Fish. Aust., 7, 1940: 169. 



31. Norman and Fraser, Giant Fishes, 1937: 59—60. 



32. Fiedler, Jarvis, and Lobell, Pesca y Industr. Pesqu. Peru, Lima, 1943: 285; Hildebrand, Bull. U.S. nat. Mus., 

 189, 1946: 51. 



33. Ogilby (Mem. Qd. Mus., 5, 1916: 95, ftn.) describes Guitarfishes in Australia as "freely entering and even perma- 

 nently residing and breeding in fresh water." 



34. We find no record of Rhinobatos from the West African Coast between about Lat. 16° S and Table Bay- 



35. Reported to Lat. 40° S (Pozzi and Bordale, An. Soc. cient. argent., 120, 1935: 153). 



36. Norman, Proc- zool. Soc. Lond., 1926: 945. 



37. Rhinobalus banksii McCulloch (Biol. Result. Fish. F. I. S. 'Endeavour', 5, 1926; 157), Australia; Rhinobatos congo- 

 lensis Giltay (Ann. Soc. Zool. Belg., sg, 1928: 21), tropical West Africa; Rhinobatos petiti Chabanaud (Bull. Mus. 

 Hist. nat. Paris, [2] i, 1929: 365), Madagascar; and Rhinobatos batillum Whitley (Aust. Zool., 9, 1939: 254), Australia. 

 Two other recently named species, R. albomaculatus Norman (Ann. Mag. nat. Hist., [10] 6, 1930: 226) and R. ir- 



