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Fishery Bulletin 109(2) 
or ledges; 2) natural habitat of flat hard bottom with 
low-relief (<0.5 m), typically limestone outcroppings and 
shallow potholes; or 3) artificial habitat, which was pri- 
marily shipwrecks but also included other non-natural 
structures (e.g., bridge pilings, building debris). Other 
habitats (seagrass, plain sand, or mud bottom) were 
uncommon and were grouped together. 
Three to nine research trips were conducted monthly 
through all seasons: winter ( January-March), spring 
(April- June), summer (July-September), and fall (Oc- 
tober-December). Sampling effort was focused on ru- 
gose hard bottom as recommended by veteran divers 
with knowledge of hogfish distribution in the study 
area, and as indicated in published reports regarding 
hogfish ecology (Davis, 1976; Colin, 1982). Remaining 
habitats were systematically surveyed less often, mainly 
to confirm the expectations that hogfish occurred there 
less frequently or in lower abundance. Attempts were 
made to visit sites representative of each combination 
of habitat type and depth category at least quarterly. 
Research dives 
Hogfish are in general unwary of divers (Davis, 1976; 
Colin, 1982) and typically remain in an area when 
divers are present (senior author, personal observ.) — a 
characteristic that makes this species a good candidate 
for visual survey techniques (Jennings et ah, 2001). 
Underwater observations using scuba were performed 
to record the presence, density, size distribution, and 
sex ratio of hogfish. 
During each dive, a single observer (A. Collins) swam 
the length of a straight line 50-m transect three con- 
secutive times. Transects were placed at the observer’s 
discretion to maximize the length of the transect over 
the targeted habitat type (typically rugose hard bottom, 
where transects were laid in a straight line on top of 
the ledge). The observer waited at least one minute 
between setting the transect line and beginning the 
survey. Additionally, the observer waited one minute be- 
tween the end of one replicate and the beginning of the 
next. During each replicate, the total number, size, and 
sex of hogfish observed within 3 m of the line were re- 
corded (survey band=6x50 m, or 300 m 2 ). The greatest 
number of fish recorded during a single replicate was 
used to calculate hogfish density in the transect area. 
Hogfish are dichromatic and dimorphic (McBride and 
Johnson, 2007). This attribute typically allowed visual 
identification of the sex of each fish. Fish were catego- 
rized as male, female, or, if sex was not obvious, sex un- 
known. Sex ratio (number of males divided by number 
of females) was calculated for each transect. The four 
cases in which a fish was designated as unknown were 
not included in the calculation of sex ratio. Maximum, 
minimum, and mean sizes of hogfish observed during 
each site visit were based on visual survey data (esti- 
mated FL, cm) as well as on harvested hogfish (mea- 
sured FL, mm). Hogfish harvested from the survey area 
were identified during the survey and were measured 
only once. 
Horizontal visibility was assessed by the observer 
during the survey. If visibility was less than 3 m, or 
if the site was too deep (>45 m) to allow for transect 
replicates, only data on fish presence were considered 
in further analyses (i.e., sex ratio and density were not 
calculated for these dives). 
The binary relationship between hogfish presence (vs. 
absence) and habitat, depth, and season were investi- 
gated by using a general linear mixed model (GLIM- 
MIX, SAS, vers. 9.1, SAS Inst., Cary, NC), and presence 
was modeled by using a binary distribution. General 
linear models (GLM and GLIMMIX) were also used to 
test for the effects of habitat, depth, and season upon 
each of the following variables: hogfish density, size, 
and sex ratio. Density was modeled with a Poisson 
distribution. 
Life history 
Hogfish were typically harvested from dive sites in 
accordance with fishing regulations; therefore most 
speared fish were greater than 305 mm FL. However, 
an effort was made to sample a number of small, suble- 
gal-size fish during each season of the year. Harvested 
fish were otherwise randomly chosen throughout the 
dive. Length (FL, mm) and whole body weight (BW, to 
the nearest 0.25 kg) were measured for all harvested 
fish. Gonads were excised immediately after the diver 
surfaced, were wrapped in plastic, and stored on ice 
until they could be returned to the laboratory. Within 
24 hours, gonads were weighed to the nearest 0.01 g, 
and a section of tissue approximately 1 cm long was 
removed from the middle of each gonad and placed 
in formalin. Histological processing followed the pro- 
cedures described in McBride and Johnson (2007). 
Slides were examined (100-200x magnification) at 
least twice by an individual reader to identify repro- 
ductive class. 
Reproductive class was assigned according to the 
method of McBride and Johnson (2007). Briefly, the 
most advanced oocyte stage or evidence of previous 
spawning (i.e., atretic advanced stage oocytes) were 
used to designate females as immature, mature rest- 
ing, mature active, or postspawning (classes 1-4, re- 
spectively). Transitional-stage fish (class 5) were iden- 
tified by the presence of seminiferous crypts along the 
boundary of the tunica. Males were classified by the 
dominant stage of spermatogenesis, the nature of the 
germinal epithelium, and the connection and size of 
sperm ducts and were designated as immature, mature 
inactive, ripening mature, ripe mature, or postspawn- 
ing (classes 6-10, respectively). 
Fish were aged by examining sectioned otoliths 
(sagittae). Age was independently assessed by two 
individual readers following the methods and cri- 
teria outlined in McBride and Richardson (2007). 
Growth was modeled with the von Bertalanffy growth 
equation: 
FL = LJ1 - *<>]>), 
