11th ICRS Abstract book - Nova Southeastern University

Oral Mini-Symposium 11: From Molecules to Moonbeams: How is Reproductive Timing Regulated in Coral Reef Organisms?
11-25
Survival Of Brooding And Broadcasting Reef Corals Following Large-Scale
Disturbances: Is There Any Hope For Broadcasting Species During Global
Warming?
Peter GLYNN* 1 , Susan COLLEY 2
1 Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami,
FL, 2 PBS&J, Ft. Lauderdale, FL
This study examines the reproductive ecology of extant equatorial eastern Pacific (EEP)
zooxanthellate scleractinian corals relative to projected global warming conditions.
Reproductive characteristics (e.g. sexuality, fecundity, timing of spawning, seasonality,
larval type, asexual propagation), colony morphology, growth, survivorship, and patterns
of abundance and distribution of 12 recently studied species in Costa Rica, Panamá, and
the Galápagos Islands are considered. All but one of these 12 EEP species are broadcast
spawners. The broadcasting species, which make up 44% of the known zooxanthellate
species occurring in the EEP (25 species), are numerically abundant, widely distributed,
and the principal reef builders in this region. Porites panamensis, which broods and
releases planulae, is a small nodular coral with a restricted distribution; it does not
contribute importantly to contemporary reef building. The majority of the broadcasting
species are highly fecund, active sexually during large parts of the year, with sexual
recruits that appear to disperse relatively far to a variety of habitats. Asexual
fragmentation is also common in broadcasting species compared with brooding species
in the EEP region. We hypothesize that diverse habitats and varying environmental
conditions (e.g., upwelling/nonupwelling centers, carbonate/basalt substrates, wet/dry
seasons, high/low turbidity, high/low productivity, El Nino/La Nina activity) would
increase the probability of survival of sexual recruits and the asexual fragments of
broadcasting species. Such refuge populations could serve as sources of larvae or
fragments to repopulate coral communities in disturbed areas. The EEP reef coral fauna,
consisting dominantly of broadcasting species, may appear to be poised to resist
extinction during global warming.
11-26
To Eat or Not To Eat? Trophic Biology of Stylophora pistillata Larvae - A Stable
Isotope Approach
Ada ALAMARU* 1,2 , Ruth YAM 3 , Aldo SHEMESH 3 , Yossi LOYA 4
1 Department of Zoology, George S. Wise Faculty of Life Sciences, Tel-Aviv University,
Eilat, Israel, 2 Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel,
3 Department of Environmental Sciences and Energy Research, Weizmann Institute of
Sciences, Rehovot, Israel, 4 Department of Zoology, George S. Wise Faculty of Life
Sciences, Tel-Aviv University, Tel-Aviv, Israel
Recruitment success of planktonic larvae to coral reefs is essential for the continued
survival of these highly diverse ecosystems. Feeding strategies may affect recruitment
success and potentially determine species distribution. The aim of this study was to
ascertain the feeding strategies of Stylophora pistillata larvae (planulae) using stable
isotopes, a powerful method utilized in dietary studies. Planulae and fragments of
parental colonies were collected from 2m and 20m depth at the coral reef of Eilat, Israel
(Gulf of Aqaba) during 2007. Carbon and Nitrogen stable isotope compositions and C/N
ratios of planulae were compared with those of parental colonies. Results showed that
δ13C of planulae was significantly lower than that of the parental colonies, but that C/N
ratio was two times higher regardless of depth. Following lipid extraction, we found no
significant difference in δ13C and in C/N values between planulae and parental colonies.
Therefore, the differences in δ13C originate in the lipid content of the planulae and not
from an isotopic fractionation during embryological development. In order to determine
if released planulae feed heterotrophically, I conducted controlled feeding experiments
using dissolved organic matter, phytoplankton and zooplankton comparing the isotopic
ratios of planulae and the food sources. To evaluate the contribution of photosynthates
translocated from the algal symbionts to the planulae, experiments were carried out under
light and dark conditions. Despite the presence of an oral opening, the planulae did not
feed. Moreover, following two weeks of “starvation” in the dark, planulae started
utilizing their lipid reservoirs, indicating the importance of photosynthesis to the
planulae. Our findings stress the importance of the physiological state of parental
colonies in producing viable planulae, capable of going through metamorphosis and
successful recruitment to coral reefs.
11-27
Sexual Reproduction And Early Life History Of Acropora Reef Corals At Moorea,
French Polynesia
Andrew CARROLL* 1,2 , Peter HARRISON 3,4 , Mehdi ADJEROUD 5,6
1 Coral Reef Research Centre, Southern Cross University, Lismore, Australia, Coffs Harbour,
Australia, 2 National Marine Science Centre, Coffs Harbour, Australia, Coffs Harbour, Australia,
Australia, 3 Coral Reef Research Centre, Southern Cross University, Lismore, Australia,
Lismore, Australia, 4 National Marine Science Centre, Coffs Harbour, Australia, Coffs Harbour,
Australia, 5 Ecole Pratique des Hautes Etudes, Perpignan, France, Perpignan, France, 6 Centres de
Recherches Insulaires et Observatoire de l’Environnement, Moorea, French Polynesia, Papetoai,
Moorea, French Polynesia, French Polynesia
This study provides the first detailed quantitative data on the sexual reproduction, larval
development and settlement competency periods of broadcast spawning Acropora reef corals at
Moorea, French Polynesia. From 2002 to 2004 the timing and mode of sexual reproduction for
Acropora reef corals was examined at four sites on the outer reef slope and reef lagoon. To
determine extent of spawning synchrony within and among species, colonies of Acropora spp.
were tagged and repeatedly sampled, or collected for spawning in flow through outdoor aquaria,
during September through November. Spawning was observed in aquaria and inferred in the
field from the disappearance of mature gametes for 13 species of Acropora, between 6-9 nights
after the full moon in September, October and November. Following spawning in November
2004, post fertilisation samples were taken from A. nasuta, A. striata and A. lutkeni to compare
the morphological stages of embryo and larval development from early cleavage to ciliated
planula larvae. Larval development and settlement competency periods were studied using A.
retusa and A. striata planulae. Larval attachment onto settlement tiles occurred within 3-4 DAS
(days after spawning) in both species. Peak periods of larval metamorphosis and permanent
settlement occurred between 4-10 DAS for A. retusa and 5-10 DAS for A. striata. The early
development and initial rapid attachment patterns of A. retusa and A. striata larvae indicate that
some planulae may be retained close to their natal reef. However, the extended settlement
competency periods observed in A. striata (31 DAS) and A. retusa (26 DAS) suggest that some
planulae also have the potential for dispersal away from their natal reef before settling. This
information is important for understanding and predicting the likely sources of larval supply to
Moorea, and examining the potential likelihood of reef interconnectivity via larval dispersal in
French Polynesia.
11-28
Reproductive Biology, Embryogenesis And Larval Development Of The Gorgonian
calicogorgia Granulosa (Gorgonacea: Plexauridae)
In-Young CHO* 1 , Jun-Im SONG 1
1 Division of EcoScience, Ewha Womans University, Seoul, Korea, Republic of
The sexual reproduction and larval development of the gorgonian, Calicogorgia granulosa were
examined in the southern most part of Korea Jejudo Island, Korea from August 2003 to March
2007. There are the unique soft coral communities with tropical and subtropical elements.
Calicogorgia granulosa is a dominant species in the communities.
The reproductive mode, gametogenic cycle, fecundity and spawning time of reproduction on the
species were assessed by using histological preparation and field surveys. Early developmental
processes from gametes, embryos to planulae have been observed under the light and stereo
microscopes.
Calicogorgia granulosa was found to be a gonochoric broadcaster. The ratio of females to
males was 1.5 : 1. Gametes were found all year round. Gametogenesis took place three times a
year and spawning of gametes occurred at new moon in March, August and November.
Spawned eggs ranging from 650 to 750 µm in diameter were spherical and dark blue. Fertilized
eggs developed into mature planulae over 4-6 days after spawning. The mature planulae were
settled on substrata on 25 days post-spawning. Especially, they preferred to settle on the lower
part of substrata. And the planulae developed into the primary polyps with 8 tentacles and oral
part within 5 days after settlement. The survival rate of planulae was recorded approximately
30% in the laboratory.
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