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



resembled the 100 mm embryo, except that all fins 

 but the pectorals were similar to those of the adult 

 and the gut was more distended with yolk. This em- 

 bryo had attacked the 49 mm (Fig. 11) and 45 mm 

 embryos present in the same uterus. 



227 AND 271 MM EMBRYOS (IRCZM 103101, 

 Fig. 15A, B).— The 227 mm female and larger 271 

 mm male embryo came from a 29 July 1977 sand 

 tiger shark. The snout was narrow and had lengthened, 

 resembling that of the adult as did other anatomical 

 features, including the fins. In both embryos the en- 

 tire digestive tract and abdominal wall were dis- 

 tended from the consumption of yolk. Many broken 

 egg capsules were also found within the uteri. 



334 MM EMBRYO (IRCZM 103135, Fig. 15C) .— 

 This was a female embryo from a 5 August 1976 sand 

 tiger shark. The stomach was distended with yolk. 

 Many "adultlike" features were apparent. This em- 

 bryo contained four smaller embryos (9-36 mm) in 

 its pharynx. 



Late Gestation, Postcannibalistic, 

 Oophagous, Preparturition Period 



(September-March; 334-1,000 mm) 



After fertilization of 0. taurus ova has ceased and all 

 other developing embryos have been consumed by 

 the surviving embryo, unfertilized ova become the 

 primary source of nutrition. This transitional period 

 begins in August-September when embryo lengths 

 reach 330-340 mm. 



Embryonic growth and development rates are rapid 

 during this period (Fig. 15C, Table 3). A 330 mm em- 

 bryo in September may attain 650-890 mm by late 

 October or early November and 830-970 mm by late 

 November. During this period the embryo consumes 

 large quantities of yolk and a length of 1.0 m may be 

 reached in December (Figs. 15D, 16). Embryos 

 reaching 1.0 m are near parturition which may take 

 place between December and March, after a gesta- 

 tion period of 9-12 mo. A maximum size of 1.2 m TL 

 may be reached before birth (Cadenat 1956). A 272 



FIGURE 15.— Four specimens of embryonic Odontaspis taurus showing progressive abdominal distention from consumed yolk: (A) A 227 mm 

 female embryo (IRCZM 103101) from the right uterus and (B) a 271 mm male embryo (IRCZM 103101) from the left uterus, of a female cap- 

 tured 29 July 1977; (C) a 334 mm female embryo (IRCZM 103135) taken from a female captured 5 August 1976; and (D) an 80-100 cm 

 embryo. 



217 



