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



FIGURE 5. — (A) Type V "short tail" gel capsules from Odontaspis taurus, containing ovalbumin and/or mucus; (B) Type IV "long tail" gel cap- 

 sules; (C) Type I blastodisc capsule, containing 16 ova; (D) Type II ovoid yolk capsules, containing 18 ova each. (Photo courtesy Marineland 

 Inc., St. Augustine, Fla.) 



29 July, respectively. The uterine fluid also increased 

 in relative cloudiness and contained numerous rup- 

 tured egg capsules and yolk fragments. 

 During early gestation the oviducal gland produced 

 at least six distinct types of egg capsules (Figs. 4, 

 5): 



Type I blastodisc capsules (Figs. 4A, 5C) — contain 7- 

 18 ova, 1-14 of which have visible blastodiscs. 

 This capsule type was more prevalent during early 

 gestation, as 83% of the intact capsules, examined 

 in a 16 May 1977 specimen, contained blas- 

 todiscs, 25% in a 28 May 1977 specimen, 22% in a 

 28 June 1976 specimen, and none in a 5 August 

 1976 specimen. The overall capsule number was 

 generally low, 15 or fewer per uterus. 



Type II ovoid yolk capsules (Fig. 5D) — consist of a 

 light amber shell membrane enclosing a rounded 

 bulbous head containing the ova and a flattened 

 transparent amber tail 40-58 mm long. We found 

 these capsules to contain a large yolk volume con- 



sisting of 7-18 ova (mean = 11), 10 mm in 

 diameter, with no sign of fertilization (i.e., no blas- 

 todisc). Springer (1948) found 16-23 ova (mean = 

 19) per capsule of this type in a female containing 

 260.4-266.7 mm embryos. Ovoid yolk capsules in- 

 creased in numbers as Type I blastodisc capsules 

 declined. Dimensions of Type II capsules ranged 

 from 2 1 to 29 X 78 to 1 18 mm and weight from 8.6 

 to 19.4 g. Ova in the egg mass during the first 2-3 

 mo of pregnancy comprised only 60-80% of the 

 capsule volume, while the remainder consisted of 

 ovalbumin and/or mucus adjacent to the tail. A 

 gelatinous ovalbumin/mucoid substance also 

 lined the inner walls of the egg capsule. 



Type III reduced yolk capsules — have the same 

 dimensions as Type LI ovoid yolk capsules but 

 contain only 1-3 ova. Type III capsules were ob- 

 served only during the first 3 mo of gestation. 



Type IV "long tail" gel capsules — contain amber, 

 green, or white gelatinous material, fluid, and no 

 ova. Although not determined, the variably 



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