526 
Fishery Bulletin 95(3), 1997 
5 : 
4 
17 32 46 58 66 
l 
100 
4 
I 
i 
{ 
3 
E 
_c 
£ 
1 t i 
Week 1 
c 2 
§ 
Q) 
5 10 15 
20 25 30 
g 
« 5 
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17 32 46 58 66 
100 
4 
i\ 
3 
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i 1 
Week 2 
i t t i , i , T , , — i 
2 
0 5 10 15 
20 25 30 
Daily feeding rate (%body wt/day) 
Figure 3 
Relation between mean daily otolith increment width and 
daily feeding rate in juvenile weakfish, Cynoscion regalis, 
during week 1 and week 2. Error bars represent 95% Tukey’s 
multiple comparison intervals. Values along the top of each 
panel are treatment feeding levels expressed as a percentage 
of maximum daily ration. 
was found to be less than daily under low ration con- 
ditions (Siegfried and Weinstein, 1989). However, for 
the bloater ( Coregonus hoyi) there was a loss of con- 
trast between the hyaline and opaque bands and no 
effect on relative increment width (Rice et al., 1985). 
Maillet and Checkley (1990) found that starved At- 
lantic menhaden ( Brevoortia tyrannus ) larvae pro- 
duced narrower increments with IW, increasing dur- 
ing a 3-6 day recovery period. In contrast to these 
examples of rapid otolith response to ration, changes 
in IW in juvenile chum salmon ( Oncorhynchus 
tshawytscha) and the tropical glass fish ( Ambassis 
vachelli ) do not become discernible for three weeks 
and two weeks, respectively (Neilson and Geen, 1985; 
Molony and Choat, 1990). Recent experimental data 
suggest that the IW-growth relation may be more 
complex than originally thought (Reznick et al., 1989; 
Secor et al., 1989; Francis et al., 1993; Jenkins et al., 
1993). The result of these studies suggests that the 
IW response to feeding and growth is variable, may 
be of limited use in some species, and needs to be 
evaluated on a species by species basis. 
For species in which the relation of IW to growth 
has been established, otolith increment analysis can 
provide a means by which an investigator may re- 
late recent environmental conditions to recent growth 
history during the important early life stages. Thus, 
a more complete understanding of the role of the 
environmental conditions relating to feeding, growth, 
and ultimately survival may be obtained. 
