Genotype-based differences in extension, calcification, and bleaching resistance
among aquacultured staghorn coral Acropora cervicornis
Kathryn E. Lohr1 and Joshua T. Patterson1,2
1University
of Florida|IFAS, School of Forest Resources and Conservation, Gainesville, Florida
2The Florida Aquarium, Center for Conservation, Apollo Beach, Florida
• Twelve 5-cm non-branching apical tips were clipped from parent colonies of 10
known genotypes within an established offshore A. cervicornis nursery
• Total linear extension (TLE), number of branches, and colony condition were
recorded for each fragment at 45-day intervals for a period of 291 days
• Buoyant weight was determined for each fragment initially and on day 122
Results
Results
Calcification
Significant differences in weight were detected between
genotypes after 122 days (ANOVA, F=2.577, p=0.01).
Letters denote differences between genotypes.
10
Frequency of bleaching was lowest among U44 colonies and
genotype was found to have a significant effect on bleaching
frequency (Χ2=42.814, df=9, p<0.001). All U25 colonies were 100%
affected.
AB AB AB AB
AB AB AB
B
Day 38
TLE = 6 cm
B
6
4
Day 162
TLE = 31 cm
2
0
U41 U78 U25 U77 K3 U73 K1 K2 U47 U44
Genotype
Linear Extension
Significant differences in net growth (square-root transformed)
were detected between genotypes (ANOVA, F=7.892, p<0.001).
Letters denote differences between genotypes. Temperature data
for the first 251 days of the experiment is overlaid.
First observation of
bleaching
80
32
60
29
40
26
20
23
0
20
0
50
100 150 200
Time (Days)
250
300
Temperature (°C)
Bleaching Response
8
A
Mean Total Linear Extension
(cm)
Buoyant Weight (g)
Objective: Determine differences in
phenotype among 10 known genotypes of
A. cervicornis
Discussion
Methods
Methods
Introduction
Introduction
Staghorn coral (Acropora cervicornis) is
critically endangered throughout its range
and is therefore widely cultured for
restoration purposes using ocean-based
nurseries. Aquaculture of staghorn coral has
produced tens of thousands of new colonies
through vegetative fragmentation, and these
have been outplanted to restore degraded
reefs. However, most restoration programs
have failed to consider phenotypic
differences between unique coral genotypes
in guiding propagation and population
enhancement activities.
E-mail: [email protected]
U41 A
U73 AB
U47 AB
K3 AB
K2 AB
U78 AB
K1 B
U77 B
U44 BC
U25 C
Temp
• Final measurements will be collected
on day 348
• Growth is believed to be an indicator
of coral health, therefore fast-growing
genotypes may have higher success
following outplanting
• Bleaching-resistant genotypes could
also be prioritized for outplanting to
improve post-outplant survivorship
• Genotypes with higher calcification-toextension ratios may resist breakage,
making them ideal for outplanting at
shallow, high-energy sites
• We aim to directly test differences in
outplant performance among the same
10 genotypes
• Preliminary data also suggest that
differences may exist in fertilization
rate between gametes
of several of the 10
Day 291
genotypes; future
TLE = 73 cm
studies will
characterize these
differences
Acknowledgements
Thanks to K. Ripple, J. Levy, J. Binstein, A.
Clark, and all CRF interns!