FISHERY BULLETIN: VOL. 81, NO. 2 



FIGURES.— Angle horizontal sagittal view of head section of a 13 mm Odontaspis taurus embryo (IRC ZM 103179). (A) Pericardial and anterior 

 coelomic cavities: (cy) coelomic yolk; (yss) yolk-sac stalk; (ysy) yolk-sac yolk; (ysm) yolk-sac membrane. (B) Yolk stalk, yolk sac, and lower 

 coelomic cavity: (ypc) yolk in pericardial cavity; (cs) cardiac stomach; (cy) coelomic yolk; (vi) valvular intestine; (ga) gill arches. 



31.0 MM EMBRYO (IRCZM 103139, Fig. 10).— 

 This encapsulated embryo was the only one present 

 in the right uterus of a 249.5 cm female 0. taurus cap- 

 tured 9 June 1976. The 7.5 mm diameter yolk sac was 

 slightly larger than that of smaller embryos ex- 

 amined. All fin buds had developed further. External 

 gill filaments were present. 



49.0 MM EMBRYO (IRCZM 103102, Fig. 11).— 

 The 49.0 mm embryo was found free in the uterus of a 

 274.2 cm TL female O. taurus caught 8 July 1978. 

 The emaciated condition, numerous small puncture 

 wounds, and absence of large numbers of branchial 

 filaments on this embryo indicated that it had been 

 attacked by the larger 131 mm embryo also present 

 in the uterus. Although the 49 mm embryo is near the 

 size range of other recently hatched embryos (i.e., SI- 

 OS mm) from 0. taurus females caught during June, it 

 also could have been torn from its egg capsule by the 

 larger embryo. Apparently also damaged by attacks 

 from the larger embryo, the yolk sac of this embryo 



was only 4 mm in diameter. Erect wide triangular 

 teeth lacking basal denticles were clearly visible. The 

 stiff, sharp structure of these teeth indicated that 

 they were functional and could have enabled the em- 

 bryo to hatch from the egg capsule. Gill filaments ex- 

 tended from the gill arches, although many were 

 damaged and probably removed when the embryo 

 was attacked. 



57 MM EMBRYO (IRCZM 103145, Fig. 12). 

 — The 57 mm embryo was found free along with an 

 unhatched 4 1 mm embryo in the left uterus of a 258. 1 

 cm TL female O. taurus captured 5 June 1976. This 

 embryo revealed maximum development in external 

 branchial filaments. Numerous long filaments extend- 

 ed from both the gill openings and spiracle (Fig. 

 12 A). A single 3.7 mm filament extended from the 

 cornea at the dorsal edge of the iris (Fig. 12B). 

 Rudimentary claspers were evident on the inner 

 margin of the pelvic fins, indicating secondary sex 

 characteristics were developing. 



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