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Fishery Bulletin 94(3). 1996 



and YOY are present May-October ( Figs. 2-4 ). Most 

 adults, however, appear to leave the estuary by mid- 

 July (Rountree, personal observ. ). The rarity of adult 

 individuals in our samples results partly because 

 they avoid gear and partly because they do not ap- 

 pear to use the shallow creeks and thus were not 

 captured in weir sampling. However, adults were fre- 

 quently observed in the bay and are often caught by 

 local fishermen during late spring-early summer 

 (Rountree, personal observ.). The near absence of 

 subadults, however, in our collections may reflect a 

 true rarity in the estuary. 



The coincidental arrival of both mature adults and 

 newborn YOY to Mid-Atlantic Bight estuaries sug- 

 gests that adults use estuaries as a parturition 

 ground. However, we did not observe any evidence 

 of parturition within the estuary during our study, 

 other than the capture of YOY presumably only days 

 old (Rountree, personal observ. I. It is not known 

 whether parturition actually occurs in the estuaries 

 or in inshore marine waters (surf zone to inner shelf) 

 or in both. Uncertainty of the importance of estuar- 

 ies as parturition habitats is underscored by the fact 

 that the use of estuaries and coastal waters is char- 



acteristic only for the northern Atlantic population. 

 The same species may only inhabit deeper shelf wa- 

 ters in other areas (Bigelow and Schroeder, 1948; 

 Baughman and Springer, 1950; Hildebrand, 1953). 

 The size of smooth dogfish at birth has been widely 

 reported as 34-39 cm (Bigelow and Schroeder, 1948; 

 Hildebrand, 1953; Heemstra, 1973; Castro, 1983; 

 Compagno, 1984), despite the fact that Bigelow and 

 Schroeder (1953) later reported size at parturition 

 to be 29-37 cm TL (11.5-14.5 inches). Because we 

 collected post parturition individuals as small as 28 

 cm TL (Fig. 2), we suggest that a range of 28-39 cm 

 TL at parturition is more accurate. However, we know 

 of no published data on size at parturition, other than 

 anecdotal accounts (Field, 1907; Smith, 1907; Fowler, 

 1918; Baughman and Springer, 1950; Hildebrand, 

 1953; Graham, 1967). Until length-frequency data 

 of full-term embryos can be compared with length- 

 frequency data for post parturition YOY, our estimate 

 of 28-39 cm at birth should be used cautiously. As- 

 suming this estimate is correct, we conclude from 

 the size distribution of YOY that parturition of YOY 

 in New Jersey waters occurs from mid-May through 

 July (Figs. 2 and 5). Similar periods of parturition 



