28 
Fishery Bulletin 1 13(1) 
ric tons of gray triggerfish annually during 1986-2011 
(Gloeckner 3 ). Landings are widely distributed along the 
East Coast of the United States, from North Carolina 
to southeast Florida. The Florida Keys account for very 
little in the way of gray triggerfish landings; headboat 
landings have averaged only 135 kg annually from 1986 
to 2011. In terms of rankings of the 2 fishery sectors, the 
recreational fishery ranks first, averaging 54.6% of the 
annual catch during 1986-2011, followed by the com- 
mercial sector (45.4%). 
Gray triggerfish are currently managed by the 
SAFMC with a minimum size limit of 305 mm (12 in) in 
total length (TL) in commercial and recreational fisher- 
ies off the eastern coast of Florida only and with a daily 
aggregate bag limit of 20 snappers or groupers per per- 
son for recreational fishermen (SAFMC 4 ). Commercial 
harvest of gray triggerfish closes once the annual catch 
limit has been reached and until the new fishing year 
begins (for example, this fishery re-opened on 1 January 
2014). 
Published studies on the aspects of life history of gray 
triggerfish from the eastern Atlantic include growth 
(Ofori-Danson, 1989; Aggrey-Fynn, 2009) and reproduc- 
tion (Ofori-Danson, 1990) studies from Ghana. Studies 
from the western Atlantic, in addition to the ones previ- 
ously mentioned, include an age and growth study from 
Brazilian waters (Bernardes, 2002), 3 unpublished col- 
lege theses in which the life history characteristics of 
populations off the SEUS coast or GOM were examined 
(Escorriola, 1991; Ingram, 2001; Moore, 2001), and a 
single published age and growth study from the Gulf of 
Mexico (Johnson and Saloman, 1984). 
We studied gray triggerfish from the SEUS because 
this species is an important resource for all reef fisheries 
in the SEUS; however, little new biological information 
has been provided in recent years. Furthermore, updat- 
ed information on the life history parameters of this fish 
is needed because NMFS is undertaking the first com- 
prehensive stock assessment of gray triggerfish collected 
from the Atlantic waters off the SEUS. This study pro- 
vides information on life history parameters of gray trig- 
gerfish collected from the commercial and recreational 
fisheries of the SEUS and provides a comparison of the 
new parameter estimates with those from previous life 
history studies conducted in the SEUS and other areas. 
Materials and methods 
Age determination 
Gray triggerfish were opportunistically sampled from 
fisheries landings along the SEUS coast from 1990 to 
3 Gloeckner, D. 2013. Unpubl. data. Southeast Fisheries 
Science Center, National Marine Fisheries Service, Miami, 
FL 33149. 
4 SAFMC (South Atlantic Fishery Management Council). 
2014. Fish ID and regs: gray triggerfish. http://www. 
safmc.net/fish-id-and-regs/gray-triggerfish, accessed 10 No- 
vember 2014. 
2012 by port agents employed by the SRHS and the 
SEFSC Trip Interview Program (TIP) to sample com- 
mercial fisheries landings. The majority of specimens 
from both fishery sectors were captured by convention- 
al vertical hook-and-line gear. A small number of fish 
(n= 5) were obtained from fishery-independent sampling 
that was conducted in Florida with traps used in the 
black sea bass fishery. Measurements of FL and TL of 
specimens were recorded in millimeters. Whole weight 
(Wj was recorded for fish landed in the headboat fish- 
ery. Fork lengths were measured for all specimens as 
standard protocol, but not all fish were weighed or 
measured for TL; therefore, weight-length relation- 
ships may have different sample sizes. Fish landed 
commercially were eviscerated at sea; therefore, whole 
weights were unavailable. Because of predetermined 
sampling protocols and time constraints imposed by 
their workload, samplers were unable to determine the 
sex of fishery-dependent specimens. 
First dorsal spines were removed from 6419 gray 
triggerfish and stored dry in coin envelopes. Spines 
were used as aging structures instead of otoliths be- 
cause gray triggerfish otoliths are small and difficult to 
extract. Spines were sectioned with a low-speed saw, ac- 
cording to the methods of Potts and Manooch (1995). A 
single 0.5-mm section was taken from the spine above 
the condyle. The sections were mounted on microscope 
slides with thermal cement and covered with mounting 
medium. Then, the sections were viewed under a dis- 
secting microscope at 12. 5x magnification with trans- 
mitted light. Each sample was assigned a ring count 
equal to the number of translucent zones. 
Three readers interpreted gray triggerfish spine sec- 
tions. Two readers (JCP and MLB) each read a sepa- 
rate portion (45%) of the sections, and a third reader 
(MC) read the other 10%. To ensure consistency among 
readers in the interpretation of growth structures, each 
individual read a calibration set of 100 spine sections, 
and the 2 primary readers each read an additional set 
of 98 spine sections, for the calculation of an index of 
average percent error (APE), by following the method 
of (Campana, 2001). 
Increment periodicity was assessed with edge anal- 
ysis. The edge type of the spine was noted: ^trans- 
lucent zone forming on the edge of the spine section; 
2=narrow opaque zone on the edge, generally <30% 
of the width of the previous opaque zone; 3=moderate 
opaque zone on the edge, generally 30-60% of the width 
of the previous opaque zone; 4=wide opaque zone on 
the edge, generally >60% of the width of the previous 
opaque zone. On the basis of edge frequency analysis, 
all samples were assigned a chronological, or calendar, 
age obtained by increasing the translucent zone count 
by one if the fish was caught before that increment was 
formed and had an edge with an opaque zone that was 
moderate to wide (type 3 or 4). All fish caught after 
translucent zone formation would have a chronological 
age equivalent to the translucent zone count. 
