GILMORE ET AL.: REPRODUCTION AND EMBRYO DEVELOPMENT OF SAND TIGER SHARKS 





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FIGURE 18.— Aquarium birth oWdontaspis taurus embryo, 15 February 1959, at Marineland Inc., St. Augustine, Fla. (A) Adult female with 

 distended abdomen; (B) initial emergence of embryo snout; (C, D) inverted emergence of head to gill openings prior to completing 

 birth. (Photos courtesy of Marineland Inc., St. Augustine, Fla.) 



about the second gill slit. For about 40 minutes 

 the pup came no farther, then it gradually moved 

 out to the origin of its pectorals. Five to 8 minutes 

 later the mother abruptly speeded up and banked 

 in the water with her belly outward. The pup 

 popped out at 1233, rose to the surface, then came 

 back to the bottom. 



"Both pups swam rapidly and rather erratically 

 until caught ... ." 



Other births observed by Wood (footnote 9) were 

 not so prolonged and were more difficult to analyze, 

 e.g., a birth occurred on 30 December 1958, within 7 

 min following a cloacal discharge. Complete emer- 

 gence of the embryo took 2-3 s. Regardless of the 

 length of birthing time, embryos have been consist- 

 ently observed to emerge headfirst. This is in con- 

 trast to recent observations of tail-first births of 

 carcharhinoids [e.g., Carcharhinus milberti (Wass 

 1973); Sphyrna mokarran (Mooney 1975); Galeocer- 

 do cuvieri (Bravo 1980)]. 



Increase in length and weight after birth in captivity 

 can be seen in Table 3. Newborn 0. taurus gain con- 

 siderable weight during the first few months. A 106 



cm, 6.2 kg pup born on 15 February 1959 was 137.5 

 cm and 19.1 kg by 29 December 1959. This same pup 

 survived in captivity until 17 March 1962. Notes 

 taken by Wood (footnote 9) point out that this 

 specimen, a male, appeared to be nearing sexual 

 maturation. At an age of 37 mo and length of 167.5 cm 

 (Table 3) the shark's claspers extended 75 mm past 

 the pelvic tips and the "general appearance" of the 

 testes indicated the shark was becoming sexually ma- 

 ture. Our observations indicate males are mature 

 when at least 191.5 cm (see Observations and De- 

 scriptions section). These data indicate that western 

 Atlantic 0. taurus may mature earlier than South Af- 

 rican specimens which were found to first mature at 

 lengths of 220 cm (Bass et al. 1975). South African 

 observations of captive 0. taurus indicate that 

 "maturity is attained after about 8 years in the 

 females . . . although the five year old male that we 

 have is not far from maturity" (van der Elst footnote 

 12). Our pregnant females from the east coast of 

 Florida ranged in size between 236.6 and 274.3 cm 

 TL. These sizes are within the range of 240-272 cm 

 for pregnant South African female 0. taurus (Bass et 

 al. 1975). 



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