501 
Population connectivity among Dry Tortugas, 
Florida, and Caribbean populations 
of mutton snapper ( Lutjanus analis), 
inferred from multiple microsatellite loci 
Email address for contact author: kshulzitski@rsmas.miami.edu 
Present address: Marine Biology and Fisheries Division 
Rosenstiel School of Marine and Atmospheric Science 
University of Miami 
4600 Rickenbacker Causeway 
Miami, Florida 33149-1098 
Abstract — Determining patterns of 
population connectivity is critical to 
the evaluation of marine reserves as 
recruitment sources for harvested 
populations. Mutton snapper (Lutja- 
nus analis) is a good test case because 
the last known major spawning aggre- 
gation in U.S. waters was granted 
no-take status in the Tortugas South 
Ecological Reserve (TSER) in 2001. 
To evaluate the TSER population as 
a recruitment source, we genotyped 
mutton snapper from the Dry Tor- 
tugas, southeast Florida, and from 
three locations across the Caribbean 
at eight microsatellite loci. Both F- 
statistics and individual-based Bayes- 
ian analyses indicated that genetic 
substructure was absent across the 
five populations. Genetic homogeneity 
of mutton snapper populations is con- 
sistent with its pelagic larval duration 
of 27 to 37 days and adult behavior 
of annual migrations to large spawn- 
ing aggregations. Statistical power of 
future genetic assessments of mutton 
snapper population connectivity may 
benefit from more comprehensive geo- 
graphic sampling, and perhaps from 
the development of less polymorphic 
DNA microsatellite loci. Research 
where alternative methods are used, 
such as the transgenerational mark- 
ing of embryonic otoliths with barium 
stable isotopes, is also needed on this 
and other species with diverse life his- 
tory characteristics to further evalu- 
ate the TSER as a recruitment source 
and to define corridors of population 
connectivity across the Caribbean and 
Florida. 
Manuscript submitted 6 October 2008. 
Manuscript accepted 20 July 2009. 
Fish. Bull. 107:501-509 (2009). 
The views and opinions expressed 
or implied in this article are those 
of the author and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Kathryn Shulzitski (contact author ) 1 
Michael A. McCartney 1 
Michael L. Burton 2 
1 Department of Biological Sciences 
Center for Marine Science 
University of North Carolina Wilmington 
5600 Marvin Moss Fane 
Wilmington, North Carolina 28409 
2 National Marine Fisheries Service 
Southeast Fisheries Science Center 
101 Pivers Island Road 
Beaufort, North Carolina 28516 
The elucidation of patterns of popula- 
tion connectivity and the determina- 
tion of sources of recruiting larvae are 
central concerns among ecologists and 
are critical for the implementation of 
spatially explicit management strate- 
gies. The marine environment provides 
a particularly complex backdrop for 
studies of connectivity because abso- 
lute barriers to dispersal are rare and 
ocean currents can be temporally and 
spatially heterogeneous. In addition, 
the majority of marine organisms have 
a pelagic larval phase, and because of 
the small sizes and patchy distribu- 
tions of individuals at this stage, it is 
nearly impossible to directly observe 
dispersal events (Leis, 1991). Genetic 
markers have often been used to infer 
dispersal scale and connectivity (Hell- 
berg, 2007). One advantage of this 
approach is that it provides informa- 
tion about effective dispersal among 
populations (i.e., only migrants that 
go on to reproduce in their new popu- 
lation will contribute gene copies). A 
second advantage is that population 
genetic structure reflects an average, 
over many generations, of migration 
events that are likely to vary sub- 
stantially over time, and therefore it 
provides an estimate of population 
connectivity that is relevant over the 
long term. 
Studies with genetic markers have 
increased our understanding of popu- 
lation connectivity in the Caribbean 
region. Shulman and Bermingham 
(1995) found weak but significant 
population subdivision across the Ca- 
ribbean basin for three out of eight 
fish species using restriction endo- 
nuclease analyses of mitochondrial 
DNA (mtDNA). Taylor and Hellberg 
(2003) examined mtDNA haplotypes 
of the sharknose goby (Elacatinus ev- 
elynae) and demonstrated extremely 
restricted dispersal among popula- 
tions. Analyses of genotypes at multi- 
ple microsatellite loci in elkhorn coral 
(. Acropora palmata) indicated two dis- 
tinct genetic groups, corresponding to 
western and eastern Caribbean sam- 
pling locations (Baums et al., 2005). 
In a recent study, Purcell et al. (2006) 
found weak genetic structure and yet 
a significant pattern of isolation-by- 
distance using microsatellite markers 
for the French grunt (Haemulon fla- 
volineatum). In contrast, the bluehead 
