11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 11: From Molecules to Moonbeams: How is reproductive timing regulated in coral reef organisms?
11.395
How Depth, Polyp Position, And Colony Size Affect Fertility Among Regions
Andrea VANEGAS* 1 , Alberto ACOSTA 2 , Angelica BATISTA 3
1 Pontificia Universidad Javeriana, Bogotá, Colombia, 2 Biology, Pontificia Universidad
Javeriana, Bogotá, Colombia, 3 Universidad Nacional de Colombia, Bogotá, Colombia
Two important geographical regions are recognized in the Atlantic; the Caribbean, and
the South Western Atlantic, where the zoanthid Palythoa caribaeorum is present.
Populations inhabiting different regions are an ideal condition to test how some variables
may affect fertility. Is already documented, within the same region, for several colonial
species, that depth, polyp position, and colony size have an important effect on fertility
(percentage of polyps with gonads); however, a latitudinal or regional comparison using
the same species have not been tested. 165 colonies were randomly sampled at Praia
Portinho, S.P., Brazil (23°N), and at Punta de Betín, Colombia (11°S) during the peak of
sexual reproduction. Fertility was quantified and the results compared between
populations according to: 1. depth (shallow: 0.5-2m; deep: 2.5-4m); 2. polyp position
within the colony (marginal; middle; center); and 3. colony size (small: ≤900cm2; large:
≥4,901cm2). Populations exhibited similar reproductive colonies (61-62%). Fertility was
statistically different between populations for depth and polyp position; with higher
values for Brazil, particularly polyps located in the center and shallow water colonies.
Fertility could be related to: 1. colony size; when a threshold distance is achieved
between marginal and center polyps, within large Brazilian colonies; 2. biotic factors (i.e.
degree of fission, and inter-specific competition), which decrease fertility in marginal
polyps when compared to the center; 3. abiotic factors (i.e. sedimentation rates, SST),
which are more benign in shallow than deeper water. In contrast, fertility between
populations was not significantly affected by colony size. The results suggest that local
variables may affect fertility. To propose a reproductive effort pattern for any species will
imply to deal with multiple synergistic factors, which act differently between regions or
latitudes.
11.396
Reproductive Cycle Of montastraea Cavernosa Linnaeus, 1767 (Cnidaria,
Scleractinia) From Southern Bahia Reefs, Brazil
Joana SILVA* 1 , Débora PIRES 1
1 Departamento de Invertebrados, Museu Nacional/Universidade Federal do Rio de
Janeiro, Brazil, Rio de Janeiro, Brazil
The reproductive cycle of the coral Montastraea cavernosa was studied in colonies
collected from southern Bahia reefs (18ºS), the richest reef area of the South Atlantic. In
Brazil, it is distributed from Pernambuco (8ºS), to Espírito Santo (20ºS), also occurring in
oceanic areas as the Parcel do Manuel Luís, Fernando de Noronha archipel and Atol das
Rocas. Patterns of reproduction, mode of development, gametogenesis and seasonal
patterns of the reproductive cycle were assessed from histological sections. The results
showed that M. cavernosa is a gonochoric and broadcasting species, with an annual
reproductive cycle which lasts for approximately 11 months. The development of the
female and male gametes started at different moments. The oogenesis lasted about 11
months, starting on March and April. The spermatic cysts were first seen on preparations
of material collected on January and remained up to three months later. The maximum
oocyte diameter measured was 417 µm. The spawning of the species in many localities in
the Caribbean occur after the full moons of July, August, September and October, during
the end of summer in the northern hemisphere. In the southwestern Atlantic, spawning
also occurred at the end of summer, when water temperature is the highest, and, during
the first days after the full moons of February and March.
11.397
Development And Substrate Preference Of Planula Larvae Of Pocillopora Damicornis In
Thailand
Pataporn KUANUI* 1 , Suchana CHAVANICH 1 , Voranop VIYAKARN 1
1 Marine Science, Chulalongkorn university, Bangkok, Thailand
In this study, the releasing period and development of planula larvae of Pocillopora damicornis
in Thailand were investigated. In addition, the substrate preference for settlement of larvae was
conducted. Ten colonies of P. damicornis, approximately 15 cm in diameter, were tagged and
collected for observation every month. To observe the releasing period of larvae, each colony
was placed in a separated tank in a rearing system until it released the planula larvae. The
results showed that P. damicornis released planula larvae during the day and night between 1-
14 days after the new moon. However, the high numbers of planula larvae were released during
3-6 days after the new moon. The releasing rates were 0.18+0.05 planula larvae per polyp.
Moreover, some colony could release planula larvae monthly. The newly released planula
larvae were approximately 1 mm in length. The larvae started attaching on a substrate with in
0.5 hour, and depressed their body shape in 1.5 hours. The polyp, tentacle, and hard structure
were observed after 40 hours. After 4 days, a juvenile coral (one polyp) started budding and
expanding its size. At the 6th month, the colony shape started uplifting. In addition, the results
of the substrate preference for settlement of larvae showed that larvae preferred to settle on the
substrates (tile, dead coral slide and rock slide) that had coralline algae covering than ones
without coralline algae (p