Bertram et al.: Growth and development during the early life stages of Pleuronectes americanus 
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Length at 30 d (mm) 
Figure 2 
(A) Age at metamorphosis versus length at 30 d. (B) 
The relationship between average larval growth rate 
and length at 30 d. 
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Length at 30 d (mm) 
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Age at maximum larval length (d) 
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Figure 3 
(A) Age at maximum larval length (untransformed) 
versus length at 30 d. (B) Latency period (untrans- 
formed) versus the age at maximum larval length. 
phosis (r= 0.22, rc=ll, P=0.52; Fig. 4A). Similarly, ju- 
venile growth rate showed no relationship to length 
at 30 d (r=— 0.001, n=10, P-0.99, Fig. 4B). For com- 
parative purposes, juvenile growth rate was also re- 
gressed against the measure of larval growth rate 
used by Bertram et al. (1993). The slope of the rela- 
tionship, -0.18 mm/d, although not significantly dif- 
ferent from 0, was identical to that reported by 
Bertram et al. (1993). 
Group-reared larvae 
Length at metamorphosis was independent of age at 
metamorphosis among members of family 3 (r=-0.09, 
rc=205, P=0.23) reared in groups as larvae and indi- 
vidually as juveniles. (Note that 175 of these larvae 
came from a single rearing aquarium and that the 
remainder were also from a single tank.) Length at 
metamorphosis ranged from 5.6 mm to 7.36 mm (6.6 
±0.3 mm). Age at metamorphosis ranged from 32 d 
to 59 d (42.6 [(±6.7] d). Individual growth rates dur- 
ing weeks 1-4 of the juvenile period were unrelated 
to age at metamorphosis (r=0.055, n- 52, P=0.71; Fig. 
5A). Juvenile growth rates were unrelated to larval 
growth rates (r=0.14, n= 52, P= 0.322; Fig 5B). Because 
juvenile growth rates were equivalent, we pooled co- 
horts that metamorphosed at different times on the 
basis of the number of days after metamorphosis. Co- 
efficients of variation for size-at-d postmetamorphosis 
were unrelated to postmetamorphic age (weeks 1-4) 
and never exceeded 0.08. 
Individual juveniles exhibited significantly faster 
growth rates during weeks 1-4 than during weeks 
5-7 (f=9.45, df=17, P<0.0001). 
