REPRODUCTION AND EMBRYONIC DEVELOPMENT OF 

 THE SAND TIGER SHARK, ODONTASPIS TAURUS (RAFINESQUE) 1 



R. Grant Gilmore 2 , Jon W. Dodrill\ and Patricia A. Linley 2 



ABSTRACT 



The capture of one ripe male, 191.5 cm TL, and 26 pregnant female, 236.6-274.3 cm TL, sand tiger sharks, 

 Odontaspis taurus, from the east-central coast of Florida from 1946 to 1980 has permitted examination of 

 early reproductive activity and embryonic development in this species. 



Variations in ovulation rates and oviducal gland activity produce six distinct egg capsule types at varying 

 times during gestation. Some egg capsules produced during early gestation contain only ovalbumin and/or 

 mucus while others contain several fertilized ova. As gestation proceeds, more capsules contain unfertilized 

 ova and ovulation rates increase. These latter capsules serve principally as food for the surviving 

 embryo. 



Sixty-two embryos, 13-1,060 mm TL, provided information on intrauterine development which allowed 

 classification of seven developmental periods based on gestation time, embryonic anatomy, posture, activity, 

 and source of nutrition. Initially, embryos 13-18.5 mmTL obtain nutrition from internal coelomicyolk sup- 

 plies during a period of early tissue differentiation. In embryos between 18.5 and 51 mmTL, consumption of 

 encapsulated yolk supplies occurs until hatching, between 49 and 63 mm TL. After hatching, the embryo ab- 

 sorbs yolk-sac nutritive supplies and may also consume uterine fluid. At about 100 mm TL, the embryo 

 begins to hunt and consume other intrauterine embryos. Seven to nine months into gestation, ova are no lon- 

 ger fertilized. In each uterus, the single remaining embryo, 334-1,060 mm TL, consumes enlarged yolk cap- 

 sules containing 7-23 unfertilized ova. Just prior to parturition the maternal ovary is greatly reduced in size, 

 few egg capsules are found within the uteri, and in each uterus the remaining embryo exhibits reduced yolk 

 consumption and an enlarged liver. Parturition observed in captivity typically takes place from December 

 through March, after 9-12 months of gestation. Newborn juveniles are about 100 cm long. 



The sand tiger shark, Odontaspis taurus (Rafinesque, 

 1810), is a cosmopolitan species distributed in sub- 

 tropical and temperate waters at depths < 60 m (Bass 

 et al. 1975). In the western Atlantic, adult sand tiger 

 sharks occur from the Gulf of Maine to Brazil 

 (Bigelow and Schroeder 1948). Although sand tiger 

 sharks have been captured on both coasts of Florida 

 (Springer 1938, 1948, 1963; Clark and von Schmidt 

 1965), captures have been more common along the 

 Florida east coast (Dodrill 4 ). 



Unlike the adults, free-swimming juvenile 0. taurus 

 in the western Atlantic are restricted only to tem- 

 perate (Bigelow and Schroeder 1953) and warm- 

 temperate waters, extending as far south as northern 

 Florida. Juveniles 109.3-157.7 cm in total length 

 (TL) have been recorded in neritic waters from the 



'Contribution No. 305, Harbor Branch Foundation, Inc., Fort 

 Pierce, Fla. 



2 Harbor Branch Foundation, Inc., R.R. 1, Box 196, Fort Pierce, 

 FL 33450. 



'District V Naturalist, Division of Recreation and Parks, Florida 

 Department of Natural Resources, Rt. 1, Box 107-AA, Clermont, 

 FL 32711. 



4 Dodrill, J. W. 1977. A hook and line survey of the sharks found 

 within five hundred meters off shore along Melbourne Beach, 

 Brevard County, Florida. Unpubl. M.S. Thesis, 304 p. Fla. Inst. 

 Technol., Melbourne, FL 32901. 



vicinity of Fernandina Beach (lat. 30°40'N, Nassau 

 County) on the Florida Atlantic coast, from Cedar 

 Key (lat. 29°15'N, Levy County) in the northeastern 

 Gulf of Mexico (Don Hoyt 5 ), and from the northern 

 Gulf of Mexico (Branstetter 1981). 



In the western Atlantic, females with near-term em- 

 bryos have been captured off eastern Florida and in 

 the northern Gulf of Mexico (Springer 1948; Hoyt 

 footnote 5; Robert Jenkins 6 ). At parturition, two 

 young are born (95-110 cm TL), one developing in 

 each uterus (Springer 1948; Cadenat 1956; Sadowsky 

 1970; Bassetal. 1975). 



Published observations on the early intrauterine 

 development of O. taurus are limited to the accounts 

 of Coles (1915), Springer (1948), Cadenat (1956), 

 andBassetal. (1975). Springer (1948) was the first to 

 observe embryonic oviphagy in O. taurus. He found 

 large quantities of yolk in the stomachs of embryos 

 dissected from females from the northern Gulf of 

 Mexico and east-central Florida. Bass et al. (1975) 

 described an intact 40 mm embryo found in the 



Manuscript accepted September 1982. 

 FISHERY BULLETIN: VOL. 81, NO. 2, 1983. 



5 Don Hoyt, Florida Shark Club, Inc., Jacksonville, FL 322 1 1 , pers. 

 commun. 1967-77. 



'Robert Jenkins, Marineland Inc., St. Augustine, FL 32084, pers. 

 commun. 1977. 



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