306 
Fishery Bulletin 116(3-4) 
10 20 
Age (days) 
10 20 30 
SL (mm) 
Figure S 
Changes in otolith size with age and standard length (SL) of laboratory-reared 
larval northern pike (Esox lucius), presented separately for sagittae (n=125, cir¬ 
cles) and lapilli (n=125, diamonds). The data are described by best-fit regressions. 
Age from sagittae: y=0.264x 2 +6.234x+6Q.14, coefficient of multiple determination 
(i? 2 )=0.97, PcO.001. Age from lapilli: y=39.457x 0 - 52 , R 2 = 0.97, P<0.001. Standard 
length from sagittae: y=1.30 7x 1 - 76 , f? 2 =0.97, P<0.001. Standard length from lapilli: 
y=9.983x-31.96, i? 2 =0.95, P<0.001. Arrows indicate approximate age and SL at 
which the growth of sagittae accelerated in contrast with that of lapilli. 
sagittae and the lapilli, as has been reported before for 
many species (Isely and Noble, 1987; Bestgen and Bun¬ 
dy, 1998). Different results were obtained for northern 
pike by Wang and Eckmann (1992), who reported that 
increment formation in lapilli started 2-3 dah. Such a 
difference in first increment formation among differ¬ 
ent studies has been reported for other species. For 
example, increment formation starts at hatching in 
larval smallmouth bass (Micropterus dolomieu ) in con¬ 
stantly fluctuating diel water temperatures (Hill and 
Bestgen, 2014). This finding contradicted the results of 
a previous study for the same species by Graham and 
Orth (1987), who reported that increment formation 
starts 7-11 dah. Similarly, Fey et ah (2005) reported 
that the first increment appeared at hatching in lar¬ 
val spot (Leiostomus xanthurus ), whereas Peters et a!. 2 
identified it at five dah at first feeding. The reasons 
for such discrepancies could be related to the otolith 
preparation method or the lack of such preparation. 
The present study is based on unprepared otoliths, but 
the paper by Wang and Eckmann (1992) is based on 
increment counts from otoliths that were ground and 
polished. Although otolith preparation by grinding and 
polishing can reveal increments and facilitate correct 
2 Peters, D. S., J. C. DeVane Jr., M. T. Boyd, L. C. Clements, 
and A. B. Powell. 1978. Preliminary observations on feed¬ 
ing, growth, and energy budget of larval spot (Leiostomus 
xanthurus). In Ann. Rep. Southeast Fish. Cent., Beaufort 
Lab. to U.S. Dep. Energy, p. 377-397. Beaufort Lab., Natl. 
Mar. Fish. Serv., NOAA, Beaufort, NC. 
r 37 
32 
27 
22 
17 
12 
Figure 4 
Growth of laboratory-reared larval northern pike (Esox 
lucius ) in standard length (SL, n=125, triangles) and 
wet weight (n=125, circles) during the first .28 days of 
life. The data are described by best-fit regressions: SL, 
y=-0.G045x 2 +0.7X7x+8.61, coefficient of multiple deter¬ 
mination (P 2 )=Q.93, P<0.001; wet weight: y=4.5Q3e°' 107x , 
J? 2 =G.94, P<0.001. Arrows indicate the age when growth 
in wet weight (bottom arrow) and SL (top arrow) of sag¬ 
ittae accelerated in contrast with that of lapilli. 
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