FISHERY BULLETIN: VOL, 69. NO. 3 



veloped and functional in all adult females ex- 

 amined, with small nidamental •glands almost 

 obsolete on the right side in some specimens; 

 both testes apparently functional, subequally de- 

 veloped in three males examined, with a single 

 epigonal organ attached to left testes. Semi- 

 lunar valves of conus arteriosus in two rows, 

 the anterior one with three valves, the posterior 

 with three much smaller valves located each on 

 the posterior base of an anterior valve. 



Color brownish or grayish above and lighter 

 below, with no conspicuous markings or abrupt 

 color changes from dorsal to ventral; expanded 

 chromatophores in the darkest specimen give a 

 peppered appearance; small areas of darker pig- 

 mentation present near tips of both dorsal and 

 caudal fins and in some specimens extending 

 along leading edges of fins; lining of buccal 

 cavity and peritoneum whitish. 



VARIATION 



The variation in morphometries among our 16 

 specimens is substantial, unusually so for a series 

 of adult sharks. Most of the difl'erences do not 

 follow sex, but it is apparent that the abdominal 

 section is longer in females than in males. Thus 

 the distance between pectoral and pelvic bases 

 ranges from 13.7 to 16.1% of total length in 

 seven males but is 16.8 to 20.0% in nine females. 

 This is similar to the situation reported for the 

 squaloid Euprotomicrus bispinatus by Hubbs, 

 Iwai, and Matsubara (1967) and in Carcharhhuis 

 leucas by Thorson, Watson, and Cowan (1966). 

 Large variations in tooth row and vertebral 

 counts were noted also. Despite the range of 

 variation between individuals and the sexual 

 dimorphism in our sample, we find nothing to 

 indicate that more than one species is repre- 

 sented or that the variation can be attributed 

 to known geographical or environmental influ- 

 ences. 



REPRODUCTION 



One 440-mm specimen in our series has par- 

 tially developed and uncalcified claspers but has 

 eggs with very early embryos in the oviducts. 



Thus the specimen is, at least functionally, a 

 female. Histological examination of the ovaries 

 was not made, but gross examination revealed 

 one ripe ovary of normal appearance but little 

 development of the other gonad. A similar in- 

 stance of the partial development of claspers by 

 a functional female Centrophoriis bisitanicus 

 was reported by Cadenat (1960). A more ex- 

 treme example, recorded by King (1966), was 

 of a hermaphroditic Scyliorhinus canicuhis with 

 a single immature clasper, a ripe ovotestis (with 

 ovarian follicles at all stages and seminiferous 

 tubules with mature sperm), and functional 

 nidamental glands, oviducts, vasa deferentia, and 

 seminal vesicles (with sperm). King also listed 

 another S. caniculus specimen with two imma- 

 ture claspers, a ripe ovotestis, and oviducts, but 

 no seminal vesicles and vasa deferentia. The 

 opposite condition was found in a field-dissected 

 specimen of Mustelus higmani by Dr. John 

 Thompson (Springer and Lowe, 1963) . This in- 

 dividual lacked claspers but had a pair of en- 

 larged testes. 



It may be significant that in the above cases 

 the size of each shark was within the range of 

 its functional sex at maturity regardless of ex- 

 ternal characters belonging to the opposite sex. 

 The lago and Centrophoriis females with clasp- 

 ers were larger than would be expected for ma- 

 ture males of the species, but the clasperless 

 male Mustelus was smaller than mature females 

 of its species. Both hermaphroditic Scyliorhinus 

 were the size of adult females of their species 

 despite the presence of claspers. 



Our smallest male, 224 mm long, is immature 

 with uncalcified claspers but six others from 

 295 to 363 mm are mature. We did not examine 

 internally a 358-mm female, the smallest of its 

 series, but eight others from 395 to 582 mm are 

 mature and have eggs in their oviducts. The 

 eggs are for the most part not large, having 

 yolks not more than 10 mm in diameter, and 

 in our specimens, embryos, when present, are 

 in a very early stage of development. In the 

 oviducts each egg is encased in a thin and soft 

 membranous shell which closely adheres to the 

 oviduct lining. The nidamental glands vary in 

 size from scarcely visible enlargements of the 

 anterior oviduct to about 10 mm in diameter, 



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