FISHERY BULLETIN: VOL. 81, NO. 2 



Drawings and Kodachrome transparencies were 

 made of various embryos, egg capsules, and re- 

 productive organs. 



OBSERVATIONS AND 

 DESCRIPTIONS 



Mating Activity 



(Mating Period, Location, and Spermatozoa) 



The occurrence of similar-size males or females in 

 unisexual groups has been documented on several 

 occasions (records of the Florida Shark Club show 

 107 0. taurus landings, Burton 1932 8 ; Sadowsky 

 1970; Bass et al. 1975; Hoyt 1976-77 see footnote 5; 

 Wood 1976-77 9 ). These observations show that 

 female groups of 0. taurus make coordinated 

 seasonal coastal movements possibly for breeding, 

 gestation, and eventually parturition (Fig. 1). 

 Females captured at the same time and location ten- 

 ded to have embryos in the same state of develop- 

 ment, suggesting coordinated breeding activity and 

 postbreeding migrations. Observations of many an- 

 nual cycles from 1947 to 1981 established winter- 

 spring as a breeding period off the Florida east coast 

 and provided comparisons of data on gestation (i.e., 

 embryonic development rates and seasonality). 



A 191.5 cm TL ripe male 0. taurus, captured 8 Feb- 

 ruary 1980 in shallow water (10 m depth) in the 

 vicinity of Fort Pierce Inlet, St. Lucie County, Fla. 

 (lat.27°25.7'N, long. 80° 12.5'W), showed evidence of 

 recent mating activity. His claspers were turgid and 

 hematose, with sperm and seminal fluid actively 

 flowing from the clasper tip. The testes were also en- 

 larged (22.5 X 3.5 cm, 0.68 kg). A larger 203 cm TL 

 male examined from Fort Macon, 1.5 km west of 

 Beaufort Inlet, N.C.(lat.34°40'N, 10 January 1978), 

 contained testes which were considerably smaller 

 (8.0 X 5.0 cm, 0.064 kg). Several scanning electron 

 micrographs were made of the sperm from the 8 Feb- 

 ruary 1980 male specimen. A single sperm had a typi- 

 cal chondrichthian helical head structure 3 1 ju.m long 

 and a tail 40.3 ju,m long (Fig. 2B). The entire length of 

 the sperm was 69-7 1.5 jLtm. Living sperm were obser- 

 ved to rotate about their long axes, propelled by the 

 circular motion of the extended tails. 



Mating scars resulting from copulatory activity 



8 E. M. Burton, The Charleston Museum, Charleston, S.C., pers. 

 commun. 24 Oct. 1932 to J. T. Nichols, American Museum of 

 Natural History, N.Y. (made available by Stewart Springer, Mote 

 Marine Lab., Sarasota, FL 33577). 



T. G. Wood, Marineland Inc., St. Augustine, FL 32084, pers. com- 

 mun. 1976-1977. 



have been commonly observed in female "galeoid" 

 sharks; however, it appears that courtship scars on 

 males are rare (Springer 1967; Stevens 1974; Pratt 

 1979). Springer (1960) had noted the presence of 

 fresh cuts on female Eulamia milberti (= Car- 

 charhinus plumgeus) in correlation with the presence 

 of early embryos. Springer (1963) found that most of 

 the 0. taurus taken in a shark fishery operating in the 

 Atlantic off east-central Florida were females with a 

 high incidence of courtship scars; but no dates were 

 given for these observations. Odontaspis taurus 

 females we captured on 9 June and 5 August 1976 

 (Table 1) had tooth puncture wounds between the 

 1st and 2d dorsal fins. The 191.5 cm male, taken on 8 

 February 1980 off Fort Pierce Inlet, had been recent- 

 ly raked by another shark along the upper left side of 

 the body behind and above the gill openings (Fig. 

 2 A). This wound consisted of eight incisions, created 

 by a narrow, long tooth rather than a flat, wide blade 

 tooth, typical of many carcharhinid sharks. As 0. 

 taurus has a long narrow tooth cusp, it is possible that 

 the wound was the result of either an attack by, or 

 copulation with, another sand tiger shark. These ob- 

 servations indicate that copulatory activity may take 

 place off the Florida east coast and therefore account 

 for the following observations of the earliest em- 

 bryonic development in specimens from this geo- 

 graphical region. 



Early Gonadal and 

 Embryonic Developmental Period 



(January-September; 0-60 mm TL) 



General Female Anatomy 



The female reproductive tract of 0. taurus may be 

 divided into the ovary, ostium, anterior oviduct, 

 oviducal gland, isthmus, uterus, and vagina, typical of 

 most galeoid sharks. Only the right ovary is 

 functional and enlarged. Above the ovary and at- 

 tached to it via membranous connective tissue 

 (mesovarium) is the ostium which collects ovulated 

 ova and distributes them to the oviducts. The two 

 oviducts (paired, right and left) bifurcate from the os- 

 tium. The anterior oviducts are about 9 mm in 

 diameter and 300 mm in length from ostium to ovidu- 

 cal glands in a 254 cm female. The heart-shaped 

 oviducal glands (53 X 93 mm in the same female) 

 function in egg capsule formation. Much larger than 

 the anterior oviduct, the portion of the oviduct 

 following the oviducal gland known as the isthmus is 

 20-34 mm in diameter, allowing for the passage of 

 multiple encapsulated ova. The isthmus opens into 



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