Bigelow: Age and growth of Onychoteuthis borealijaponica 



method. There was some evidence that males (stage 

 IV-V) and females (stage III— IV) in the western 

 North Pacific were younger than similar stage in- 

 dividuals from the central and eastern North Pacific. 



Discussion 



The data presented provide support for the one-in- 

 crement-deposited-per-day hypothesis within the 

 statoliths of Onychoteuthis borealijaponica although 

 further work is required to rigorously test the hy- 

 pothesis. Tetracycline was incorporated into the sta- 

 tolith, but the animals did not feed and survival was 

 not sufficiently long enough (2-3 days) to provide a 

 rigorous test on the rate of increment deposition. 

 Validation of the daily increment hypothesis has 

 come from tetracycline labeled statolith experiments 

 with several neritic squid species (Illex illecebrosus, 

 Dawe et al., 1985, Alloteuthis subulata, Lipinski, 

 1986, Todarodes pacificus, Nakamura and Sakurai, 

 1991). Future statolith validation experiments with 



