NOTE Pierce et al.: Age and growth of Harenguta jaguana in Florida waters 
207 
A West Palm Beach 
o 
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CL, 
50 
40 h 
30 
20 
10 
0 
50 r- 
40 - 
30 
20 
10 
0 
50 
40 
30 
20 
10 
0 
50 
40 
30 
20 
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50 (- 
40 
30 
20 
10 
0 
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30 
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J l 
Feb 1992 
« = 471 
...1 .J -1-1. - I JL 
May 1992 
n = 188 
1 1 i 1 f 1 -1 
iJI »1 li I I 
Jun 1992 
n = 1298 
Aug 1992 
n = 253 
Oct 1992 
n = 93 
l-l-l-I I, 
1 
Nov 1992 
n = 196 
±... 1 I 1 I I I I 
_ at jan 1993 
_ 92 — I— « = 51 
— IM Jun -/Jul. 92 
Jm i i i 
i i i i i i 
oct. 92 Mar 1993 
n = 42 
LI 
-Lml— 1 I I I 1 1 I 
Sep 1992 
n = 61 
1 .1 1 J 
May 1993 
n = 142 
Nov. 92 
Sept 92 
.JL_J J 
Aug 1993 
Apr. 93 n = 901 
Mar. 93 
Jan. 93 . 
Oct 1993 
n = 379 
l-l I I I I 
40 60 80 100 120 140 160 40 60 80 100 120 140 160 
Fork length (mm) 
Figure 4 
Observed monthly fork length frequencies of H. jaguana collected from off West Palm 
Beach and in Tampa Bay, Florida. Cohort age was determined from the sagittal micro- 
structure and labeled with the estimated spawn date. (A) West Palm Beach 1992-93; 
(B I Tampa Bay 1993. 
that H. jaguana larvae <8.9-mm TL did not show any 
ossification and that maxillaries and dentaries in the 
head region were first to ossify at 14.0 mm TL; but these 
authors did not describe the formation of the otoliths 
(sagittae, lapilli, or asterisci) for laboratory hatched and 
reared larvae collected from south Florida. Therefore, the 
first identifiable increment about the core could form as 
early as 4-5 days (yolksac absorption) to 14 days (first 
ossification in the head region) after hatching but no later 
than transformation into juvenile (25 days after hatch- 
ing). Thus, growth from the daily counts could be underes- 
timated by 4-25 days. 
Hubold and Mazzetti ( 1982) calculated a von Bertalanffy 
growth curve for H. jaguana in Guanabara Bay, Brazil, 
based upon three values of length-at-age assigned from 
length-frequency analyses of fish caught in July 1979. 
They identified only two modal length-at-age groups — 105 
mm (age 2) and 140 mm FL (age 3) — estimating the mean 
length at age 1 to be 40 mm FL. Applying either Houde 
and Palko’s (1970) (0.7 mm TL/day growth rate for labora- 
