311 
Abstract— We examined the age 
and growth of dusky grouper 
(. Epinephelus marginatus) at off- 
shore Carpinteiro Bank (32°16'S; 
52°47'W) in the southwestern 
Atlantic through the analysis of 
growth increments in otoliths. 
We also examined the hypoth- 
esis that this offshore habitat 
represents a superior site for 
fish growth compared with in- 
shore habitats. Samples con- 
sisted of 211 groupers captured 
by small-scale fisheries between 
2008 and 2011 and with total 
lengths ranging from 150 to 
1160 mm. Otolith growth incre- 
ments were deposited once per 
year, and opaque bands formed 
mostly during the summer, as 
determined through marginal 
increment analysis. Ages ranged 
from 1 to 40 years, and most fish 
were aged to be between 2 and 
8 years (global mean: 7.4 years, 
standard deviation 6.9). Von 
Bertalanffy growth parameters 
for pooled sexes were Loo=900.9 
mm, A!=0.129 and to= _ l-45. Fish 
from the offshore habitat were 
generally older and their mean 
sizes were significantly larger 
at ages 3, 4, 5, and 6 than those 
of fish from the inshore habi- 
tat. Our findings highlight the 
importance of Carpinteiro Bank 
as an important growth habitat 
for dusky groupers in the south- 
western Atlantic and indicate 
that fishery management mea- 
sures should be implemented to 
ensure the maintenance of this 
endangered species in this off- 
shore bank in the future. 
Manuscript submitted 18 June 2013. 
Manuscript accepted 22 August 2014. 
Fish. Bull. 112:311-321 (2014). 
doi:10.7755/FB.112.4.7 
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. 
Age and growth of dusky grouper ( Epinephelus 
marginatus ) (Perciformes: Epinephelidae) 
in the southwestern Atlantic, with a size 
comparison of offshore and littoral habitats 
Mario V. Condini (contact author ) 1 
Cristiano Q. Albuquerque 2 
Alexandre M. Garcia 1 
Email address for contact author: mvcondmi@gmail.com 
1 Instituto de Oceanografia 
Universidade Federal do Rio Grande 
Avenida Italia km 8, Carreiros 
96201-900, Rio Grande 
Rio Grande do Sul, Brazil 
2 Departamento de Oceanografia e Ecologia 
Universidade Federal do Espirito Santo 
29075-900, Vitoria 
Espirito Santo, Brazil 
The dusky grouper (Epinephelus 
marginatus) (Epinephelidae) inhab- 
its shelter-rich, hard substrata on the 
continental shelf along the eastern 
coast of South America from Brazil to 
Argentina (Figueiredo and Menezes, 
1980; Irigoyen et ah, 2005), through- 
out the Mediterranean Sea, and from 
the British Isles around the southern 
tip of Africa (Heemstra and Randall, 
1993) to southern Mozambique (Fen- 
nessy, 2006). Adults inhabit rocky 
bottoms, generally at depths up to 50 
m, and they can be found occasion- 
ally at depths up to 250 m (Brusle, 
1985; Heemstra and Randall, 1993), 
whereas juveniles are usually found 
in coastal tide pools (Azevedo et ah, 
1995). Like other epinephelids, the 
dusky grouper is a slow-growing pro- 
togynous hermaphrodite species with 
late sexual maturation and low nat- 
ural mortality rates (Manooch and 
Mason, 1987), and it is also a highly 
valuable commercial fish (Heemstra 
and Randall, 1993). These combined 
characteristics make the dusky grou- 
per highly vulnerable to overfishing. 
This species is classified as endan- 
gered by the International Union for 
Conservation of Nature (Cornish and 
Harmelin-Vivien, 2004), with a de- 
creasing global population trend. 
The dusky grouper is the only 
large epinephelid that is usually 
found along the extreme southern 
part of the Brazilian coast, where it 
is fished over inshore rocky bottoms 
(depths <5 m) and offshore banks 
(depths >10 m) by small-scale fish- 
eries (Condini et ah, 2007). Offshore 
populations of dusky grouper occa- 
sionally are targeted opportunistical- 
ly by large-scale commercial fisheries 
that use hand lines, but the species 
is otherwise not a commercially tar- 
geted species. The most frequently 
visited site in the southwestern At- 
lantic for commercial offshore fishing 
of this species is Carpinteiro Bank. 
The role of dusky groupers in the 
coastal ecosystems of South America 
is not completely understood. Given 
the likely importance of this spe- 
cies as a predator (Rehones et ah, 
2002), it is imperative to understand 
the implications of any sort of com- 
mercial exploitation that may be 
involved. To prevent stock collapse, 
reef fishes should be fished carefully 
because slow-growing, late-maturing 
fish species are found frequently in 
coastal ecosystems and are vulner- 
