80 



Fishery Bulletin 101(1) 



described by other authors (e.g. Casey et 

 al., 1985; Branstetter, 1987b; Simpfendorfer, 

 1993). There were 239 young of the year R. 

 terraenovae collected during this study, 88 of 

 which contained no discernible birth mark. 

 All young of the year lacking a birth mark 

 were captured in June and July (Fig. 10), 

 whereas all young of the year captured from 

 August through April had a birth mark. Both 

 marked and unmarked centra were noted in 

 July and showed a readily apparent trend; 

 individuals with a birth mark were sig- 

 nificantly larger than those without a birth- 

 mark (/-test, df=96, ^=-7.138, P<0.0001). 



Back-calculated lengths-at-age were sim- 

 ilar to observed lengths-at-age in all cases, 

 although observed values were slightly 

 higher for all age classes (Table 1). There 

 was no evidence of Lee s phenomenon in the 

 older age classes. Back-calculated size at 

 the birth mark overestimated size at birth 

 as determined by observations of neonates 

 and full-term embryos. 



The VBGE estimates calculated by age 

 class, actual age, and back-calculated age 

 demonstrated little variation either within or among 

 data types (Table 2). The VBGE parameters from all 

 data types corresponded well with known life his- 

 tory parameters for size at birth and maximum size. 

 Unless otherwise noted, all comparisons throughout 

 the remainder of this study were based on VBGE es- 

 timates derived from the "actual age" data type. 



Discussion 



Reproduction 



Length-at-maturity estimates for male R. terraeno- 

 vae were similar among the three published studies. 

 Parsons ( 1983b) estimated male maturity at -610 to 

 653 mm PCL (lengths from other studies were con- 

 verted to PCL by using the formulae derived from the 

 current study) and Branstetter (1987a) estimated 

 the same at 600 mm PCL. We determined that males 

 reach full maturity at -600 to 615 mm PCL. The 

 three studies failed to agree on length at maturity 

 for female R. terraenovae. Branstetter (1987a) and 

 Parsons (1983b) approximated the size of females at 

 maturity at 660 mm PCL and from 650 to 690 mm 

 PCL, respectively. We found, however, that females 

 mature at a smaller size, from 590 to 610 mm PCL. 



The reproductive seasonality of R. terraenovae in our 

 study appeared to lack synchrony; males reached their 

 reproductive peak in April and females in May and June. 

 Mature males dissected in late May and June had vis- 

 ibly atrophied testes compared to those collected in April 

 and early May. However, their seminal vesicles were still 

 highly swollen and contained large amounts of semen. 

 This condition indicated that male R. terraenovae were 



still capable of mating during May and June, when female 

 MOD values were highest. Therefore, the mating season 

 of fl. terraenovae off the southeastern U.S. coast appeared 

 to last from mid May to early July. Simpfendorfer (1992) 

 noted a similar misalignment of peaks in reproductive 

 seasonality between the sexes in R. taylori. 



The largest litters noted in our study contained eight 

 pups (/?=4l. This increases the maximum litter size re- 

 ported for R terraenovae in the northwestern Atlantic 



