FISHERY BULLETIN: VOL. 85, NO. 3 



vae are more abundant in surface night sets ap- 

 pears unusual since Richards and Kendall (1973) 

 found that in winter larvae 8-17 mm were more 

 abundant in deep tows at night and surface tows 

 during the day. Avoidance behavior does not ap- 

 pear to develop until a size of greater than 10 mm 

 (Norcross et al. 1961; Potter and Lough in press). 

 Assuming the same for larvae in Fortune Bay, it 

 is not likely that yolk-sac larvae were avoiding 

 the gear during the day. Although it is not possi- 

 ble to make a definite conclusion on vertical mi- 

 gration with the relatively small number of lar- 

 vae, the data suggest that yolk-sac larvae in 

 February are also capable of vertical migration. 



Our analyses of sand lance larvae from Fortune 

 Bay have demonstrated for the first time the oc- 

 currence and probable spawning of the slender- 

 bodied A. da hi us in coastal waters in Newfound- 

 land. Previous studies by Winters (1970) have 

 indicated the occurrence of only the deep-bodied 

 form A. americanus in Newfoundland bays with 

 A. dubius being found exclusively on the offshore 

 banks. This finding is significant in light of the 

 current confusion as to the appropriate taxonomy 

 of the sand lance populations in the Northwest 

 Atlantic. Both A. americanus and A. dubius ap- 

 pear to resemble A. nutrinus which is currently 

 considered to occur only in European waters 

 iReay 1970), and the characteristics used to sepa- 

 rate the two Northwest Atlantic types from each 

 other and from A. marinus are sometimes tenu- 

 ous particularly in southern parts of the range. In 

 the Newfoundland area, however, A. americanus 

 and A. dubius maintain distinct meristic counts. 

 The occurrence and probable spawning of A. du- 

 bius in a coastal area, formerly considered to be 

 inhabited exclusively by A. americanus (Winters 

 1970), indicates sympatry. This provides evidence 

 that the two forms are reproductively isolated 

 and therefore separate species. This is substanti- 

 ated by the fact that the meristics described for A. 

 dubius larvae in Fortune Bay and those offshore 

 (Winters 1970) are identical. 



We have also demonstrated that the spawning 

 season of sand lance in Fortune Bay, Newfound- 

 land, is protracted and probably extends from De- 

 cember to May or June. This spawning period is 

 much longer than in southern areas of the North- 

 west Atlantic where the spawning season in in- 

 shore waters is from the period December to 

 February (Richards 1982). It is possible that this 

 extended spawning season is also a result of the 

 mixture of the two species in Fortune Bay; how- 

 ever, the polymodality in the length frequency of 



large A. dubius (>20 mm) larvae in Fortune Bay 

 suggests that an extended spawning season may 

 be characteristic of this species in coastal New- 

 foundland waters. 



ACKI^JOWLEDGMENTS 



The authors acknowledge the technical staff of 

 the Pelagic Section of Science Branch who partic- 

 ipated in the ichthyoplankton surveys in Fortune 

 Bay. In particular we wish to thank B. W. Slaney 

 for carrying out the laboratory procedures to 

 double-strain the larvae. We also thank S. A. 

 Akenhead, I-H. Ni and J. Carscadden for review- 

 ing a draft of the manuscript. 



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