3.1 X farther north at Isla Las Animas (Klimley 

 1981; Klimley and Nelson 1981). Similar dispari- 

 ties in sex ratios were also observed in sandbar 

 sharks by Springer ( 1960). He felt that adult male 

 sandbar sharks live over a large geographical and 

 depth range, perhaps in deep cool oceanic waters 

 inaccessible to the fishermen's gear, while fe- 

 males occur in warmer inshore water where they 

 are more accessible to fishermen. He suggested 

 that the males move inshore only to mate. We had 

 insufficient data to test this suggestion in our 

 sample area. 



Castro (1983) reported that S. lewini from 

 North American waters probably mature at about 

 180 cm; he did not mention whether this length 

 referred to male, female, or both. Bass et al. 

 (1975) reported that male scalloped hammerhead 

 at Mozambique matured between 140 and 165 

 cm, reaching a maximum length of at least 295 

 cm; females matured at about 212 cm, reaching at 

 least 309 cm. Compagno (1984) reported "maxi- 

 mum" sizes ranging from 370 to 420 cm. Our 

 largest males were 305 cm TL, and the smallest 

 mature male was 198 cm TL. The largest female 

 observed was 324 cm, and the smallest mature 

 female was 210 cm. It seems that in our sample 

 area, males reached maturity at a somewhat 

 larger size than in the other studied areas while 

 females were about the same. 



The close relationship of growth pattern of 

 uterine embryos and ovarian eggs implies that 

 eggs are transferred into the uterus and fertilized 

 immediately after parturition. If the estimate of 

 10 month gestation period is correct, adult fe- 

 males give birth once each year. 



The length at birth of scalloped hammerheads 

 has been reported to be around 50 cm from Natal 

 and southern Mozambique coastal waters (Bass et 

 al. 1975), 43 cm from northeastern United States 

 to Chesapeake Bay waters (Casey 1964), 38-45 

 cm in North American waters (Castro 1983), and 

 42-55 cm combined from all oceans (Compagno 

 1984). Our largest uterine embryos measured 

 about 47 cm TL. 



Pupping season appears to be during the sum- 

 mer in Taiwan as well as in Mozambique (Bass et 

 al. 1975) and North America (Castro 1983). In 

 Hawaii, Clarke (1971) found newborn pups 

 throughout the year but with increased numbers 

 in summer. 



Fisheries Center, National Marine Fisheries Ser- 

 vice, NOAA, for reading the first draft of this 

 manuscript and offering useful comments. We 

 also thank Jin-Jehn Wu, Department of Fish- 

 eries, National Taiwan College of Marine Science 

 and Technology, for his help in collecting speci- 

 mens. Financial support was received from Na- 

 tional Science Council (contract: NSC 72-0409- 

 B019091 and NSC 73-0409-B019-02). 



Literature Cited 



Bass, A. J . J D. D' Aubrey, and N Kistnasamy. 



1975. Sharks of the east coast of southern Africa. III. The 

 families Carcharinidae and Sphymidae. Oceanogr. 

 Res. Inst., Durban, Invest. Rep. No. 38, 100 p. 

 Casey, J G 



1964. Angler's guide to sharks of the northeastern United 

 States, Maine to Chesapeake Bay. Bur. Sport Fish. 

 Wildl., Circ. No. 179, 32 p. 

 Castro, J I. 



1983. The sharks of North American waters. Texas 

 A&M Univ. Press, 180 p. 



Clarke, T A 



1971. The ecology of the scalloped hammerhead shark, 

 Sphyrna lewini, in Hawaii. Pac. Sci. 25:133-144. 

 Compagno, L J. V. 



1984. FAO species catalogue. Vol. 4. Sharks of the world. 

 An annotated and illustrated catalogue of shark species 

 known to date. Psirt 2. Carchariniformes. FAO Fish. 

 Synop. No. 125, 4(2):251-655. 



Klimley, A. P 



1981. Grouping behavior in the scalloped hammer- 

 head. Oceans 24(4):65-71. 

 Klimley. A P and D R. Nelson 



1981. Schooling of scalloped hammerhead shark, Sphyrna 

 lewini, in the Gulf of California. Fish. Bull., U.S. 

 79:356-360. 

 Schlermitzauer, D a , and P W. Gilbert. 



1966. Placentation and associated aspects of gestation in 

 bonnethead shark, Shyrna tiburo. J. Morph. 120:219- 

 231. 

 Springer, S. 



1960. Natural history of the sandbar shark, Eulamia mil- 

 berti. U.S. Fish. Wildl. Serv., Bull. 61:1-38. 

 Teshima, K. 



1981. Studies on the reproduction of Japanese smooth 

 dogfish, Mustelus manazo, and M. griseus. J. Shi- 

 monoseki Univ. Fish. 29:113-119. 



Che-Tsung Chen 



Tzyh-Chang Leu 



Shoou-Jeng Joung 



Graduate School of Fisheries 



National Taiwan College of Marine Science 



and Technology 

 Keelung, Taiwan 

 Republic of China 



Acknowledgments 



We sincerely thank Susumu Kato, Southwest 



393 



