202 
Age and growth of the scaled herring, 
Harengula jaguana, from Florida waters, 
as indicated by microstructure of the sagittae 
Daryl J. Pierce 
Behzad Mahmoudi 
Florida Fish and Wildlife Conservation Commission 
Florida Marine Research Institute 
100 Eighth Avenue S. E. 
St. Petersburg, Florida 33701-5095 
Present address (for D J Pierce): RR1 71 Hack Road 
Dalton, Pennsylvania 18414 
E-mail address (for D. J. Pierce): daryljp@aol.com 
Raymond R. Wilson Jr. 
College of Marine Science 
University of South Florida 
140 7th Avenue South 
St. Petersburg, Florida 33071-5095 
Scaled herrings, Harengula jaguana 
(Clupeidae), inhabit nearshore (40-m 
isobath, rarely 500-m) warm temper- 
ate and tropical waters of the western 
Atlantic Ocean from coastal New Jersey 
to off southern Brazil, including the 
waters of Bermuda, the Gulf of Mexico, 
and the Caribbean Sea (Whitehead, 
1985). They are an important link in 
the nearshore neritic food web as pred- 
ators of zooplankton and as common 
prey for many species of piscivorous 
fishes, sea birds, and marine mam- 
mals (Odum and Heald, 1972; Carr 
and Adams, 1973; Reintjes 1 ). Although 
H. jaguana is popular live bait for 
anglers throughout Florida, it has rela- 
tively minor commercial importance as 
bycatch in regional purse-seine fisher- 
ies. However, Houde (1977) estimated 
a potential yield of 41-92 million kg 
per year for this species from a survey 
of H. jaguana eggs and larvae in the 
eastern Gulf of Mexico. 
Limited age and growth information 
exists for H. jaguana. Martinez and 
Houde (1975) reported ages of up to 
three years determined from scale cir- 
culi of fish collected from Biscayne Bay, 
Florida. Hubold and Mazzetti (1982) 
identified three age groups of H. ja- 
guana from Guanabara Bay, Brazil, 
with length-frequency analysis. How- 
ever, daily growth increments of oto- 
liths provide a better means of aging 
short-lived species (Pannella, 1974; 
Brothers et al., 1976) and are typical- 
ly better for age determination than 
are scales (Jones, 1992). The objective 
of our study was therefore to deter- 
mine ages from validated periodicities 
of otolith (sagittal daily rings and to 
use the ages and lengths to compare 
growth rates of H. jaguana from the 
Atlantic coast with those from the Gulf 
coast of Florida. 
Materials and methods 
Adult H. jaguana were sampled monthly 
from commercial purse-seine catches 
from nearshore waters adjacent to West 
Palm Beach and Tampa Bay, Florida, 
between February 1992 and December 
1993. By using cast nets, juvenile and 
adult fish were collected monthly in 
Tampa Bay and in alternate months 
near West Palm Beach. From each 
sample (purse-seine and cast net) 
the sex of approximately 100 fish 
was determined, and these fish were 
measured to the nearest 1.0 mm 
(standard, fork, and total lengths) 
and weighed to 0.1 g. Length-length 
and sex-specific weight-length relation- 
ships were computed for each coast. 
Weight-length regressions from log 10 - 
transformed data were described by 
least-squares linear regression and 
tested for differences between sexes 
within each coast and between coasts 
by analysis of covariance (ANCOVA). 
A total of 4210 (30 to 174 mm FL) H. 
jaguana were collected from off West 
Palm Beach and 29,994 (30 to 179 mm 
FL) fish were collected from Tampa 
Bay. 
Each month, sagittae were removed 
from four fish randomly selected from 
within each 10-mm-FL (fork length) 
size class, sex, and coast. Otoliths were 
cleaned and stored dry in labeled con- 
tainers. Sagittae were then processed, 
sectioned (transverse), and aged as in 
Secor et al. (1991) using an Olympus 
BH-2 compound microscope with trans- 
mitted light at 500x. Sagittae were 
read three separate times by the same 
reader in random sequence with a 
two-week interval between counts. In- 
crement counting began at the first 
identifiable increment around the core 
(presumed to be day one) and contin- 
ued along the medial plane of the sul- 
cal ventral lip. Age was taken as the 
arithmetic mean of the three counts of 
the daily rings and accepted for analy- 
sis if the range of the three did not vary 
more than 10% from the mean. All re- 
jected sagittae were counted a fourth 
time to replace the most extreme count, 
but were removed from further analy- 
sis if rejected a second time. The sex- 
specific relationship of otolith radius 
(core to medial edge of the sagitta) to 
fish length (FL) was linearly regressed 
for aged fish from each coast to ex- 
amine the relationship between otolith 
growth and somatic fish growth. 
During fall 1995 , H. jaguana (50-80 
mm FL) were marked with tetracycline 
and held in indoor tanks (568-L Nal- 
gene tanks with a subgravel filtration 
system) to validate daily increment for- 
mation. Aquariums were kept at water 
1 Reintjes, J. W. 1979. Coastal herrings 
and associated species: a profile of species 
or groups of species, their biology, ecology, 
current exploitation with economic and 
social information. Submitted to the Gulf 
of Mexico Fish. Manage. Council SEFC/ 
NMFS NOAA, Beaufort, NC 28516, 170 p. 
Manuscript accepted 13 September 2000. 
Fish. Bull. 99:202-209 (2001). 
