232 
Abstract — Distribution and demo- 
graphics of the hogfish ( Laclinolai - 
mus maximus) were investigated by 
using a combined approach of in situ 
observations and life history analyses. 
Presence, density, size, age, and size 
and age at sex change all varied with 
depth in the eastern Gulf of Mexico. 
Hogfish (64-774 mm fork length and 
0-19 years old) were observed year- 
round and were most common over 
complex, natural hard bottom habi- 
tat. As depth increased, the presence 
and density of hogfish decreased, but 
mean size and age increased. Size 
at age was smaller nearshore (<30 
m). Length and age at sex change 
of nearshore hogfish were half those 
of offshore hogfish and were coinci- 
dent with the minimum legal size 
limit. Fishing pressure is presum- 
ably greater nearshore and presents 
a confounding source of increased 
mortality; however, a strong red tide 
occurred the year before this study 
began and likely also affected near- 
shore demographics. Nevertheless, 
these data indicate ontogenetic migra- 
tion and escapement of fast-growing 
fish to offshore habitat, both of which 
should reduce the likelihood of fish- 
ing-induced evolution. Data regarding 
the hogfish fishery are limited and 
regionally dependent, which has con- 
founded previous stock assessments; 
however, the spatially explicit vital 
rates reported herein can be applied 
to future monitoring efforts. 
Manuscript submitted 29 September 2010. 
Manuscript accepted 24 February 2011. 
Fish. Bull. 109:232-242. 
The views and opinions expressed 
or implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National Marine 
Fisheries Service, NOAA. 
Demographics by depth: spatially explicit 
life-history dynamics of a protogynous reef fish 
Angela B. Collins (contact author ) 1 
Richard S. McBride 2 
Email address for contact author: angela.collins@myfwc.com 
1 Florida Fish and Wildlife Conservation Commission 
Fish and Wildlife Research Institute 
100 8th Avenue SE 
Saint Petersburg, Florida 33701 
2 Northeast Fisheries Science Center 
National Marine Fisheries Service 
National Oceanic and Atmospheric Administration 
166 Water Street 
Woods Hole, Massachusetts 02543 
Protogynous species require special 
management considerations when fish- 
ing reduces the probability of survival 
to the male phase. Selective harvest- 
ing of males may skew the sex ratio 
and reduce the reproductive capacity 
of a population by increasing the prob- 
ability of sperm limitation (Hamilton 
et al., 2007). Also, selective removal 
of a particular sex or size class over 
many generations can have evolution- 
ary consequences, including slower 
growth rates, reduced size at matu- 
ration, and earlier sexual transfor- 
mation (Harris and McGovern, 1997; 
Adams et ah, 2000; Brule et al., 2003; 
Heppell et al., 2006). However, pro- 
togyny does not automatically imply 
elevated vulnerability to fishing if the 
population is able to compensate for 
reduced male survival (e.g., by earlier 
transition to the male phase). This 
ability to compensate is most likely to 
occur in species in which sex change is 
socially or environmentally mediated 
rather than constrained to a certain 
size or age (Alonzo and Mangel, 2005). 
Therefore, to predict stock dynam- 
ics and a species’ response to fishing 
pressure, it is important not only to 
establish whether sex change occurs, 
but also to quantify the mechanisms 
that influence sex change and charac- 
terize the related demographics. 
We synthesized data from in situ 
observations and life history collec- 
tions to evaluate factors that could 
potentially influence the presence, 
density, and demographics of a reef 
fish. The hogfish (Labridae: Lachno- 
lairnus maximus ), which occurs from 
temperate to tropical waters of the 
western North Atlantic Ocean, Gulf 
of Mexico, and Caribbean Sea, was 
chosen for this study for several rea- 
sons. It is an economically important 
reef fish (for a list of total U.S. fish- 
ery landings and their estimated val- 
ues see: www.st.nmfs.noaa.gov/stl/ 
commercial/index. html, accessed Feb- 
ruary 2011), and a better understand- 
ing of its ecology will assist manag- 
ers in evaluating regulatory options. 
The principal fishing method for this 
species is spearfishing (McBride and 
Richardson, 2007), which presents 
an opportunity to evaluate the effect 
of a single fishery sector with fewer 
confounding effects from other fish- 
ery sectors (e.g., hook-and-line). Hog- 
fish can exceed 800 mm fork length 
(FL), weigh more than 10 kg, and 
live as long as 23 years (McBride 
and Richardson, 2007). These life- 
history characteristics allow a wide 
latitude for measuring differences in 
size and age. Finally, they are mo- 
nandric, protogynous hermaphrodites 
(all fish begin life as female and can 
eventually change sex to male) (Mc- 
Bride and Johnson, 2007) that form 
harems, with a single male control- 
ling 2-15 females (Davis, 1976; Colin, 
1982; Claro et al., 1989). This mat- 
ing system allowed for investigation 
of the effects of fishing, habitat, and 
other environmental variables on sex 
change and social structure. 
