Bolz and Burns: Age and growth of larval Clupea harengus 



395 



be expected to fill with air. Enlargement at this time 

 of the lapilli and, less dramatically, of the sagittae 

 and maculae would allow larvae to take greater ad- 

 vantage of the wave amplification conferred by a full 

 air bladder and bullae. In order to successfully avoid 

 predation and to control vertical migration, this 

 should occur at as early an age as possible. Analysis 

 of otolith growth is probably the only way to esti- 

 mate the timing of this developmental landmark in 

 field-caught larvae. Knowing when this occurs may 



permit a better understanding of population anoma- 

 lies. The necessary morphometric data are lacking 

 for the 1976-77 season; however, from the analysis 

 of recent seasons, the storm events in late Novem- 

 ber 1976 would be expected to have occurred while 

 many of the larvae were at this critical life stage. 

 This co-occurrence of storm events and critical life- 

 stage events would have caused additional mortal- 

 ity to an already stressed population. 



