Lunar periodicity of planula release in the reef-building coral Stylophora pistillata

Self Cite

Over the last century, considerable research has been dedicated to investigating life history traits of coral planulae. However, despite the universality of coral propagules and their deduced ecological properties, there is no clear understanding of some basic biological issues such as ecological and evolutionary forces that determine sexual reproduction and larval behavior in hermatypic corals. To further evaluate ecological trajectories in sexual reproduction of the hermatypic coral Stylophora pistillata from Eilat, Red Sea, we collected 22 900 planulae from 313 S. pistillata colonies in situ during March to July (2004July ( to 2006. Variations in reproductive effort were observed between years, but during all reproductive seasons, the larvae tended to settle ex situ in aggregates of kin (61.71% to 82.4%; 2005 values). During a 6 mo survey, the spat grew at a rate of 3.4 to 5.4 polyps mo -1 . Peaks of planula shedding were documented for April to June, suggesting a shift in reproductive seasonality compared to the preceding 2 to 3 decades. Ex situ settlement of collected larvae revealed, for the first time, settlement polymorphism of early versus late larvae throughout the reproductive season; the March settlement rate was the highest (43.7%) and June was the lowest (26.2%). A reverse trend was documented for settlement rates on the first post-planulation night, with only 2.2% settlement in March versus 46.2% in July. Early season larvae of S. pistillata are therefore capable of dispersing farther than late season propagules. These results are diametrically opposed to the 'desperate larva hypothesis,' revealing different ecological traits of early versus late season larvae.

Section: Discussionsupporting

confidence: 92%

“…Each trap was made of a plastic container, connected to a 120 µm plankton net through a plastic funnel ( Fig. 1a; see also photograph in Zakai et al 2006). A 7 cm diameter hole in the container's lid was lined with nylon mesh to allow free water exchange in the field.…”

Section: Methodsmentioning

confidence: 99%

Coral planulae as dispersion vehicles: biological properties of larvae released early and late in the season

Amar¹,

Chadwick²,

Rinkevich³

2007

Self Cite

“…Lack of lunar periodicity in planula release has been observed in Stylophora pistillata in the Red Sea (Rinkevich & Loya 1979, Shlesinger & Loya 1985, but see Zakai et al 2006) and is indicated by the relative uniformity in lunar distribution of larval occurrence in coral fragments in the Great Barrier Reef (Tanner 1996). However, such reproductive behavior is not the case for populations in the north Pacific (Palau, Atoda 1947b;Taiwan, Fan et al 2002; Philippines, the present study).…”

Section: Discussioncontrasting

confidence: 42%

“…Upon collection, the colonies were transported a few kilometers from the reef to the hatchery facility of the Marine Science Institute's Bolinao Marine Laboratory for ex situ monitoring of planulation. Ex situ planulation monitoring has previously been shown to capture the same temporal pattern in planula release as that in the field (Jokiel et al 1985, Zakai et al 2006. Monitoring of planulation started at new moon (±1 d).…”

Section: Methodsmentioning

confidence: 87%

Timing of planulation by pocilloporid corals in the northwestern Philippines

Villanueva¹,

Yap²,

Montaño³

2008

We determined the lunar, seasonal, and diel timing of larval release in several species in the scleractinian family Pocilloporidae at Bolinao in the northwestern Philippines. All of the species exhibited remarkable lunar periodicity in planula release, with distinct timing in the lunar calendar. Despite confinement of peak larval release between the first quarter and full moons in 4 species (Pocillopora damicornis, P. verrucosa, Stylophora pistillata, and Seriatopora guttatus), only the 2 Pocillopora species experienced significant overlap in release times. Disparate lunar timing, on the other hand, was exhibited by the 3 Seriatopora species (new moon for S. caliendrum, last quarter moon for S. hystrix, and full moon for S. guttatus) during warm-dry months, although during seasons with low planulation rates the timing for the former 2 species seemed to overlap. Generally, lunar reproductive patterns in each species were seasonally consistent despite strong variations in larval output. The highest rates of planulation were recorded during the warm-dry months (March to May) and the lowest during the warm-wet months (June to October), except for P. damicornis, in which the lowest rate occurred during the cool-dry months (November to February). The timing of release in P. damicornis is mainly during the dark period of the diel cycle, with a peak at ca. 02:30 h. This report highlights the variation in timing of planulation among closely related coral species and compares temporal planulation data in the Philippines, which lies within the Indo-West Pacific center of coral diversity, to available data on brooding pocilloporid corals from other biogeographic regions.KEY WORDS: Pocillopora · Seriatopora · Stylophora · Reproduction · Planulae · Lunar periodicity · Seasonality · Bolinao · BrooderResale or republication not permitted without written consent of the publisher

“…Planulae and parental corals were sampled by SCUBA from 2 m and 20 m depth during the major reproductive season of the species, from February to May 2007, in front of the Interuniversity Institute for Marine Sciences at Eilat (IUI; 29°30.05' N, 34°55' E). Planula larvae were collected from parental colonies using plankton traps (120 µm mesh) placed over the colonies at sunset and removed early in the morning (Rinkevich & Loya 1979, Zakai et al 2006. Each gravid colony we sampled was measured, and a nubbin was taken for stable isotope analysis.…”

Section: Methodsmentioning

confidence: 99%

Trophic biology of Stylophora pistillata larvae: evidence from stable isotope analysis

Alamaru¹,

Yam²,

Shemesh³

et al. 2009

The successful recruitment of planktonic larvae to coral reefs is essential for the continued existence of these highly diverse ecosystems. Feeding strategies may affect recruitment success and potentially determine species distribution by controlling the dispersal range of the larvae. Our aim here was to ascertain the feeding strategies of planula larvae of the coral Stylophora pistillata by using stable isotopes. Planula larvae, fragments of parental colonies, and 3 potential food types were analyzed for carbon and nitrogen stable isotope compositions and C/N ratios. We found that planulae were depleted in 13 C when compared to parental tissues, whereas their C/N ratios were 2-fold higher. Following lipid extraction, there were no significant differences in δ 13 C values and C/N ratios between lipid-free planulae and parental colonies. This indicates that the differences in δ 13 C originate in the lipid content of the planulae and not from any isotopic fractionation that may occur during embryological development. Controlled feeding experiments were conducted using phytoplankton, zooplankton, and bacteria. Despite the presence of an oral opening, the planulae did not show any feeding behavior, and the stable isotope data corroborated the observations of no feeding. Moreover, following 2 wk of starvation in the dark, planulae started to utilize their lipid and protein reservoirs. These results stress the importance of the photosynthates translocated from the algal symbionts to these planulae as an energy source.