11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 11: From Molecules to Moonbeams: How is reproductive timing regulated in coral reef organisms?
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Molecular Cloning And Expression Analysis Of Yolk Proteins in The Hermatypic
Coral galaxea Fascicularis
Hideki HAYAKAWA 1 , Toshiki WATANABE* 2 , Tadashi ANDOH 3
1 Ocean Research Institite, The University of Tokyo, Tokyo, Japan, 2 Ocean Research
Institute, The University of Tokyo, Tokyo, Japan, 3 Hokkaido National Fisheries Research
Institute, Fisheries Research Agency, Kushiro, Japan
During oogenesis corals accumulate yolk, consisting of proteins, lipids and
polysaccharides, in the cytoplasm of developing oocytes. In corals, molecular
mechanisms by which vitellogenesis (yolk formation) is controlled remain totally
unknown. In the present study, cDNAs encoding yolk proteins were cloned in the
gonochoric coral Galaxea fascicularis and their expression was studied, with the purpose
of studying mechanisms of transcriptional regulation and identifying tissues synthesizing
those proteins. In eggs released by female colonies of G. fascicularis, four major soluble
proteins (named GfEP-1 – 4) were detected. GfEP-1 – 3 were not detected in pseudoeggs
(infertile eggs produced by male colonies), and GfEP-4 was present in pseudo-eggs
at a lower concentration than in eggs. cDNAs encoding these proteins were cloned and
sequenced. The results showed that a single mRNA encodes a long precursor protein
(named GfVg), which is subsequently processed to generate GfEP-1 – 3. The GfVg
sequence was homologous to vitellogenin, the yolk protein precursor in higher animals
including vertebrates. GfEP-4 is encoded by a separate mRNA, and its sequence did not
exhibit similarity to any known proteins. Preliminary analysis of egg extracts from four
other corals suggest that GfVg, but not GfEP-4, occurs ubiquitously among hermatypic
corals. Immuno-histochemical analysis showed that GfVg is synthesized in tissues
outside of the ovary and transported to oocytes. GfVg are synthesized in gastrodermal
cells covering the inner side of the body wall and transported to oocytes in the mesentery
via the mesoglea. A preliminary analysis has shown that the transcription of the GfVg
mRNA is activated in females, but not in males, in the presence of estradiol-17 at the
nominal concentration of 1 mg/L.
11.388
Higher Temperatures Drive Early Larval Release Of Brooding Reef Corals
Yu-Chieh HSIEH* 1 , Tung-Yung FAN 2 , Peter J. EDMUNDS 3 , Lee-Shing FANG 4
1 Institute of Marine Biodiversity and Evolution, National Dong Hwa University, Taiwan,
Pingtung, Taiwan, 2 National Museum of Marine Biology and Aquarium, Taiwan,
Pingtung, Taiwan, 3 Department of Biology, California State University, Northridge, CA,
USA, Northridge, CA, 4 Cheng Shiu University, Taiwan, Kaohsiung, Taiwan
The accurate timing and tight sychronization of reproductive events typically play a
critical role in reproductive success, and previous studies have shown that this is
particularly important for scleractinian corals. In this study, we described larval release of
two brooding reef corals, Pocillopora damicornis and Seriatopora hystrix in Southern
Taiwan, to demonstrate that the timing of larval release can be altered dramatically by
temperature. Corals were collected from shallow locations in Nanwan Bay and
maintained in outdoor, flow-through systems to quantify daily larval release over
multiple years. The mean lunar day representing the peak of larval release cycle was
analyzed by circular statistics. The two coral species released larvae throughout the year
with lunar cycles in both 2003 and 2005, and importantly, the lunar cycle of larval release
shown apparent seasonal variation in each year. The mean lunar day for larval release by
the two species was 3.4 to 12.2 in summer (April to October), but 8.3 to 21.9 in winter
(November to March). In 2007, however, the lunar cycle of larval release did not show
seasonal variation, the mean lunar day of larval release was similar in winter and summer
(6.2 to 12.5). Notably, the mean lunar day of larval release in February and March was
earlier in 2007 (8.6-9.6) than in previous years (11.5-19.3), and the mean monthly
seawater temperature in between November 2006 and February 2007 was 1.1-2.8 o C
warmer than that during the winters of 2003 and 2005 .The early larval release February
and March 2007 may be driven by the higher seawater temperature in winter 2006. These
results are important as they suggests that coral reproductive timing may be influenced by
rising temperatures associated with global warming.
11.389
Gametogenesis Of The Hermatypic Coral siderastrea Siderea in Broward County, Fl,
Usa And The Effect Of Bleaching On Fecundity
Adam T. ST.GELAIS* 1 , Alison L. MOULDING 1 , David S. GILLIAM 1 , Vladimir
KOSMYNIN 2 , Richard E. DODGE 1
1 National Coral Reef Institute, NSU Oceanographic Center, Dania Beach, FL, 2 Florida
Department of Environmental Protection, Tallahassee, FL
Massive Caribbean scleractinians are slow to replace themselves in the population due to long
life spans, low recruitment, and slow growth rates. Disruption of reproductive synchronicity or
reduced fecundity may adversely affect their ability to recover and repopulate degraded areas.
Reproductive information on Siderastrea siderea, an abundant Caribbean broadcast spawning
species, is particularly sparse. In order to track gametogenesis and identify the time of
spawning, tissue samples from S. siderea were collected from August 2007 on a weekly basis
until November, when a reduction in gametes, indicative of spawning, was observed. Estimated
spawning time was compared with lunar phase as well as water temperature data obtained from
permanent digital temperature recorders deployed throughout Broward County to determine if
either of these environmental cues affected spawning time. Information on colony condition and
presence of bleaching was obtained for each colony sampled. Tissue samples were processed
for histological analysis and examined for late stage gametes. Fecundity was estimated from
measurements of the volume of oocytes cm-2tissue and was compared between bleached and
unbleached colonies. Initial analysis suggests that S. siderea spawned between November 8
and 11, 2007 which coincided with the new moon on November 9th. Samples collected on the
8thcontained both ova and spermaries extruded from the mesenteries into the gastrovascular
cavity and un-spawned gametes absorbed by the gastrodermis. Further collections of S. siderea
in 2008 will be used to corroborate spawning correlation of S. siderea with lunar period.
11.390
Spawning Patterns Of Corals in North-Western Philippines
Kareen VICENTUAN* 1 , James GUEST 2 , Maria Vanessa BARIA 1 , Patrick CABAITAN 1 ,
Rommi DIZON 1 , Ronald VILLANUEVA 1 , Porfirio ALIÑO 1 , Alasdair EDWARDS 2 , Edgardo
GOMEZ 1 , Andrew HEYWARD 3
1 Marine Science Institute, University of the Philippines, Quezon City, Philippines, 2 School of
Biology, Newcastle University, Newcastle upon Tyne, United Kingdom, 3 Botany Biology
Building, Australian Institute of Marine Science, Crawley, Australia
The Philippines has more than 30,000 km2 of reef area and is host to some of the world’s most
diverse and endangered coral communities, however there is very little information on patterns
of coral reproduction. Sampling to determine the reproductive state of Acropora species and in
situ observations of coral spawning were conducted during March to June in 2006 and 2007 at
sites close to the Bolinao Marine Laboratory in north-western Luzon. Prior to the full moon in
March 2006, at least 22 Acropora species (96%) and 67% of colonies sampled (n = 208)
contained visible white or pigmented oocytes in branches that were fractured artificially in situ -
indicating a seasonal peak in reproductive activity. Night dives were carried out during the
week following the full moons of 15 March and 14 April 2006; and 2 April, 2 May and 1 June
2007. Multi-species coral spawning was observed during all of the months of observation
except in April 2007. A total of at least 36 scleractinian species belonging to 14 genera and 7
families (Acroporidae, Mussidae, Agariciidae, Faviidae, Oculinidae, Merulinidae and Poritidae)
were observed to broadcast spawn, with a maximum of 13 species observed to spawn on the
fifth night after the full moon in May 2007.
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