FISHERY BULLETIN: VOL. 74, NO. 1 



area contained 231 daily increments, the mar- 

 ginal area contained 120, and there were 94 

 thinner marks in the middle zone. Working back- 

 wards from the 2 July collection date, this indi- 

 cated the slow growth zone occurred in December, 

 January, and February. These figures correspond 

 well with the known life cycle (Scofield 1931) 

 which suggests a fast growth period in spring, 

 summer, and fall (230 days, ~ 8 mo), a short 

 winter of slow growth (~ 3 mo), and a spring and 

 early summer (~ 4 mo) of faster growth prior to 

 capture. 



Otoliths of postlarvae of the gobies Clevelandia 

 ios, Ilypnus gilherti, and Quietula y-cauda were 

 also examined. The fish were collected in Mission 

 Bay, San Diego. The 2-mo larval period indicated 

 in the otoliths agree with several independent 

 estimates of the length of time between hatching 

 and settlement (Brothers 1975). 



Otoliths of two species of hake obtained from 

 the Gulf of California were studied. Mathews 

 ( 1975) has shown that annual marks (annuli) may 

 be detected by means of the usual discrimination 

 of hyaline and opaque zones in Merluccius an- 

 gustimanus while in Merluccius sp. (Mathews in 

 press) the same techniques have also been applied 

 successfully. The ages of hake determined by 

 means of annuli may be compared with age 

 determined from counting the number of daily 

 increments; these are identified by analogy with 

 the structures shown to be daily in their incidence 

 in anchovy, grunion, striped bass, and other fish 

 and which appear to be the same as those shown 

 by Pannella (1971) to be daily in M. bilinearis 

 (Figures 5, 6). In most cases, direct total counts 

 were not possible because increments were not 

 equally visible over a complete nucleus to margin 

 radius. For these otoliths measurements of incre- 



^ 



50jjm 



I I 



^ 



O 



I 



Figure 5. — a) Nucleus of an otolith from aMer- 

 luccius sp., 7 yr old; b) daily growth increments 

 shown from near the center of the otolith. 



