Journal Articles - UP - MSI
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- A unique reproductive strategy in the mushroom coral Fungia fungitesEyal-Shaham, Lee; Eyal, Gal; Ben-Zvi, Or; Sakai, Kazuhiko; Harii, Saki; Sinniger, Frederic; Hirose, Mamiko; Cabaitan, Patrick; Bronstein, Omri; Feldman, Bar; Shlesinger, Tom; Levy, Oren; Loya, Yossi (Springer Science and Business Media LLC, 2020-09-30)The vast majority of scleractinian corals are either simultaneous hermaphrodites or gonochoric. Exceptions to these are rare. Nevertheless, species belonging to the family Fungiidae are known to exhibit a wide variety of reproductive strategies. We examined the reproductive ecology of the mushroom coral Fungia fungites in Okinawa. Our study was conducted as part of a long-term, wide-ranging project (2009–2010 and 2013–2017) which explored the unique reproductive strategies of several species belonging to the family Fungiidae. Here we report the co-occurrence of males, females, and hermaphrodite individuals in a long-term monitored population of the reproductively atypical brooder coral F. fungites within the family Fungiidae. F. fungites status as a single-polyped solitary coral, was used to perform manipulative experiments to determine the degree of dependence of an individual coral on its conspecific neighbors for reproduction, and examined whether a constant sperm supply is obligatory for the continuous production of planulae. Isolated females of F. fungites exhibited a distinctive reproductive strategy, expressed in continuously releasing planulae also in the absence of males. Observations conducted on a daily basis for 2.5 months (throughout the reproductive season of 2015) revealed that some of these individuals released planulae continuously, often between tens and hundreds every day. In an effort to explain this phenomenon, three hypotheses are discussed: (1) Self-fertilization; (2) Asexual production of planulae (i.e., parthenogenetic larvae); and (3) Extended storage of sperm. Finally, we emphasize the importance of continuous and long-term monitoring of studies of coral reproduction; through further genetic studies of coral populations representing a broad range of species and their larval origin.
- Partial mortality in Porites corals: Variation among Philippine reefsWesseling, Ineke; Uychiaoco, Andre J.; Aliño, Porfirio M.; Vermaat, Jan E. (Wiley, 2001-01)Partial mortality or tissue necrosis was quantified in the massive scleractinian coral Porites at three sites in The Philippines (Bolinao, NW Luzon; Puerto Galera, Mindoro; and El Nido, N Palawan). Overall, 15 ± 1 (mean ± 1 standard error, 642 replicates) percent of colony area was dead, mean colony area was 1135 plusmn; 127 cm2, and lesion density was 1.7 ± 0.1 dm—2. Total live coral cover varied between 20 and 63% in belt transects, and Porites and Acropora cover were inversely correlated. ANOVA models incorporating effects of site, colony size, sedimentation rates, wave exposure and depth were highly significant but explained only a small proportion of the variation observed in lesion density and percent dead area (respectively 8 and 2%). Lesion density was found to vary significantly with site (contributed 29% to this explained variance), decrease with increasing colony area (33%), and increase with increasing sedimentation (23%) and wave exposure (14%). Colony size was significantly explained by the factor site (contributing 61% to the total 29% explained variance) and depth (34%), with the smallest colonies being observed in Bolinao and the largest in El Nido. Densities of lesions were highest in Bolinao, intermediate in Puerto Galera, and lowest in El Nido. This pattern is parallel to intensity of human reef exploitation and opposite to that in colony size, live coral cover and Acropora cover. Since only a small part of the observed variance in partial mortality estimators was explained by the ANOVAs, other factors not quantified here must have been more important (e.g. disease incidence, predation, human exploitation).
- Spatial and short-term temporal patterns of octocoral assemblages in the West Philippine SeaLalas, Jue Alef A.; Lim, Romina Therese S.; Cabasan, Joey P.; Segumalian, Christine S.; Luciano, Rhea Mae A.; Valino, Darryl Anthony M.; Jacinto, Melchor R.; Arceo, Hazel O.; Baria-Rodriguez, Maria Vanessa (Frontiers Media SA, 2022-01-06)Octocorals are relatively understudied than other coral reef organisms despite their ecological and economic values. The Philippines is known to have high marine biodiversity, but information on octocorals is lacking. This study investigated spatial and temporal variations in the assemblage of octocorals in selected reef sites in the West Philippine Sea (WPS)- the Kalayaan Island Group (i.e., Pag-asa, Sabina, Lawak, and Northeast Investigator) and Ulugan in 2017 and 2019. Results showed high octocoral taxonomic richness (at least 10 families) in the study sites. Mean percent octocoral cover in WPS was 5.35% SE ± 0.55, with Sabina having the highest octocoral cover in both years. Significant differences in octocoral cover were observed among sites in both years, but among-station differences were only observed in 2017. Octocoral assemblage also differed among sites in both years (ANOSIM: R > 0.5, p < 0.05), wherein different octocoral taxa dominated in different sites. In particular, variations were driven by high cover of holaxonians, nephtheids, and coelogorgiids in Sabina, and clavulariids, tubiporiids, and xeniids in Northeast Investigator in 2017. In 2019, significant variations were driven by high cover of helioporiids in Pag-asa, while Sabina had higher abundance of holaxonians, nephtheids, alcyoniids, and xeniids. Short-term temporal variation on octocoral cover in monitoring stations in Pag-asa was not observed (Kruskal-Wallis, p > 0.05), although the overall mean octocoral cover increased from 1.23% ± SE 0.47 in 2017 to 2.09% SE ± 0.37 in 2019. Further, there was no significant change in the octocoral assemblage in Pag-asa between years (ANOSIM, R = 0.11, p = 0.07). This study highlights high octocoral taxonomic richness in the WPS relative to other sites in the Indo-Pacific Region and provides baseline information on the octocoral assemblages, which can be useful for future ecological studies and marine biodiversity conservation efforts.We would like to thank the Department of Agriculture-Bureau of Fisheries and Aquatic Resources (DA-BFAR), Philippine Coast Guard (PCG), the Municipality of Kalayaan, and the Philippine Navy for their assistance and support during the research expeditions in the West Philippine Sea. We also thank Lovely Joy Heyres for assisting in the field collection and image analysis, and Kevin Yatco and Socorro Rodrigo for assisting in the satellite product processing. We also thank the valuable insights and suggestions given by the editor and reviewers of this journal that helped improve this manuscript.
- Survival and sexual maturity of sexually propagated Acropora verweyi corals 4 years after outplantationLigson, Charlon A.; Cabaitan, Patrick C. (Wiley, 2021-04-19)Most coral reef restoration efforts are carried out over 1–2 years, and few have assessed long-term (over 3 years) outcomes. Although studies of outplantation of sexually propagated corals have reported promising initial results, few studies have followed outplanted corals to maturity. Here, we monitored sexually propagated Acropora verweyi corals for 4 years post-outplantation to determine their survival and sexual maturity. These corals were outplanted when 4 months old in two size classes (small = 0.3–0.5 cm; large = 1.0–1.5 cm) at two sites in the northwestern Philippines. Four years after outplantation, the 240 colonies of A. verweyi exhibited 17.9% survival, with mean diameters ranging from 7.48–26.8 cm. Most of the surviving outplants were gravid (81.4% of the 43 colonies) with mean diameters of at least 11.8 cm. Higher survivorship was detected in the initial large size class outplants than in the small ones at the natal site, but not at the other site. However, 4 years after outplantation, there was no significant difference in terms of geometric mean diameter between the initial size classes or between the sites. Results show that 4-month-old outplants of sexually propagated corals can survive until sexual maturity and are already capable of contributing gametes for the potential recovery of degraded coral communities at age 4 years.The authors are grateful to Ronald de Guzman, Francis Kenith Adolfo,and Renato Adolfo for the field and hatchery assistance.This study was supported by a grant from the Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development of the Department of Science and Technology to PCC. The authors are also grateful to Prof. Peter Harrison for providing CAL a research assistantship opportunity and for additional logistical support through an Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development.
- Latitudinal variation in growth and survival of juvenile corals in the West and South PacificNozawa, Yoko; Villanueva, Ronald D.; Munasik, Munasik; Roeroe, Kakaskasen Andreas; Mezaki, Takuma; Kawai, Takashi; Guest, James; Arakaki, Seiji; Suzuki, Go; Tanangonan, Jean J. B.; Ang, Put O.; Edmunds, Peter J. (Springer, 2021-08-18)Reef-building corals are found across > 30° of latitude from tropical to temperate regions, where they occupy habitats greatly differing in seawater temperature and light regimes. It remains largely unknown, however, how the demography of corals differs across this gradient of environmental conditions. Variation in coral growth is especially important to coral populations, because aspects of coral demography are dependent on colony size, with both fecundity and survivorship increasing with larger colonies. Here we tested for latitudinal variation in annual growth rate and survival of juvenile corals, using 11 study locations extending from 17° S to 33° N in the West and South Pacific. Regression analyses revealed a significant decline in annual growth rates with increasing latitude, whereas no significant latitudinal pattern was detected in annual survival. Seawater temperature showed a significant and positive association with annual growth rates. Growth rates varied among the four common genera, allowing them to be ranked Acropora > Pocillopora > Porites > Dipsastraea. Acropora and Pocillopora showed more variation in growth rates across latitudes than Porites and Dipsastraea. Although the present data have limitations with regard to difference in depths, survey periods, and replication among locations, they provide evidence that a higher capacity for growth of individual colonies may facilitate population growth, and hence population recovery following disturbances, at lower latitudes. These trends are likely to be best developed in Acropora and Pocillopora, which have high rates of colony growth.We appreciate volunteers, students, and assistants for data collection. Y.N. especially thank H.-S. Hsieh and C.-H. Liu for data measurement, and V. Denis for his comments on the manuscript. Comments from two anonymous reviewers improve our manuscript greatly. The study was funded by the thematic research grant of Academia Sinica (23-2g) and an internal research grant of Biodiversity Research Center, Academia Sinica to Y.N. The Okinawa survey was partly supported by the Japan Society for the Promotion of Science through NEXT Program #GR083. Temperature data for the Okinawa site were provided by the coral reef survey of Monitoring Sites 1000 Project, operated by the Ministry of the Environment, Japan. Temperature data for Moorea were provided by the Moorea Coral Reef LTER, funded by the US National Science Foundation (OCE-0417412).
- Zooxanthellae diversity and coral-symbiont associations in the Philippine archipelago: specificity and adaptability across thermal gradientsTorres, Andrew F.; Valino, Darryl Anthony M.; Ravago-Gotanco, Rachel (Frontiers Media SA, 2021-10-20)Prolonged thermal stress and high levels of solar irradiance can disrupt the coral-algal symbiosis and cause bleaching and lowered overall fitness that lead to the likely death of the cnidarian host. Adaptive bleaching and acclimatization of corals, which posits bleaching as an opportunity for the coral host to switch its currently susceptible endosymbionts to more stress-tolerant taxa, offers hope for survival of reefs amid rapidly warming oceans. In this study, we explored the diversity and distribution of coral-zooxanthellae associations in the context of geospatial patterns of sea surface temperature (SST) and thermal anomalies across the Philippine archipelago. Thermal clusters based on annual sea surface temperature means and each site’s frequency of exposure to heat stress were described using three-decade (1985–2018) remotely sensed data. Haphazard sampling of 628 coral fragments was conducted in 14 reef sites over 3 years (2015–2018). Using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting and sequencing of the zooxanthellae ITS2 region, we characterized endosymbiont diversity within four reef-building coral families across archipelagic thermal regimes. Consistency in dominant Symbiodiniaceae taxon was observed in Acropora spp., Porites spp., and Heliopora coerulea. In contrast, the family Pocilloporidae (Pocillopora spp., Seriatopora spp., and Stylophora pistillata) exhibited biogeographic variability in zooxanthellae composition, concordant with inferred occurrences of sustained thermal stress. Multivariate analyses identify two broad Pocilloporidae clusters that correspond with mean SST ranges and frequency of exposure to bleaching-level thermal stress which are largely supported by ANOSIM. Differences in zooxanthellae assemblages may reflect host-specific responses to ecological or environmental gradients across biogeographic regions. Such patterns of variability provide insight and support for the adaptability and potential resilience of coral communities in geographically and oceanographically complex regions, especially amidst the increasing severity of global and local-scale stressors.This paper is dedicated to the late Ronald D. Villanueva whose contribution to the project during its inception has been invaluable. The authors thank Patrick R. Pata and the reviewers LE and RC-T for their helpful comments and suggestions, and acknowledge Hazel O. Arceo, Cesar L. Villanoy, and Maria Lourdes San Diego-McGlone for their support of this study. Eileen Peñaflor and Mariana Soppa shared key knowledge in processing satellite products. Mikhael Tañedo, Romer Albino, Emmeline Jamodiong, David Siquioco, Lovely Heyres, Rhea Luciano, Joey Cabasan, Frederico Sabban, Geminne Manzano, Clairecynth Yu, Joyce Velos, Joseph Garcia, Robert Casauay, Maryjune Cabiguin, Macy A onuevo-Arcega, Ariel Loja, Jerome Genilan, Amabelle Go, Jamie Dichaves, Elaine Saniel, and Miledel Quibilan assisted with field collections. Supporting hard coral data were provided by the DOST-PCAARRD NACRE Program and the DENR-BMB WPS and SECURE Philippine Rise Projects. This is MSI contribution number 486.
- Trends in growth and mortality of three coral species (Anthozoa: Scleractinia), including effects of transplantationYap, H. T.; Alino, P. M.; Gomez, E. D. (Inter-Research Science Center, 1992)Three ecologically dominant coral species in a northern Philippine reef were compared in terms of growth and mortality and responses to transplantation. The purpose of this study was to examine the feasibility of using the species concerned in establishing new coral populations through deliberate fragmentation. The species, Acropora hyacinthus, Pocillopora damicornis and Pavona frondifera, displayed distinct differences which could be related to their respective life-history strategies. A. hyacinthus showed tendencies towards an r-mode, with rapid linear growth but also high mortality rates. Response to transplantation was poor. Pocillopora damicornis had intermediate linear growth rates and relatively high mortality. Transplants fared poorly in the initial part of the experiment though they showed successful adaptation after a year. Mortality rates of both A. hyacinthus and P. damicornis were increased by high temperatures during certain times of the year. Pavona frondifera had the highest linear growth rates and no mortality, tending towards a K-mode of life history strategy. It showed the best response to transplantation This species is thus a suitable candidate for large-scale reef restoration.
- Sexual reproduction in the soft coral Lobophytum schoedei in Bolinao‐Anda Reef Complex, Pangasinan, northwestern PhilippinesBaran, Christine C.; Baria‐Rodriguez, Maria Vanessa (Wiley, 2021-04-02)The characterization of early life-history strategies of soft corals is important in understanding population maintenance, replenishment, and recovery in disturbed coral reefs. This study examined the sexual reproduction of the soft coral Lobophytum schoedei in the Bolinao-Anda Reef Complex (BARC), a degraded reef in northwestern Philippines. Reproductive strategies such as sexuality, sex ratio, fecundity, and reproductive timing were examined. Random colonies of L. schoedei were sampled a few weeks before the predicted time of spawning to assess fecundity (n = 73 colonies), and sexuality and sex ratio (n = 221 colonies). Monthly sampling of tagged colonies of L. schoedei (n = 20) was done over 13 months to determine the reproductive timing through polyp dissection. Peak of annual spawning was inferred based on the presence of large gametes and their absence in the next sampling period. Results showed that L. schoedei is a gonochoric broadcast spawner with 1:1.1 sex ratio. Although oogenesis and spermatogenesis exhibited overlapping cycles, both gametes matured and spawned in April, coinciding with increasing sea surface temperature. Prior to spawning, oocytes and spermaries ranged 300–633 µm and 150–337 µm in diameter, respectively. Mean female fecundity was 6.7 ± 3.9 oocytes per polyp and male fecundity was 39.2 ± 22.5 (±SD) spermaries per polyp. Some of these results, including the low number of oocytes produced by female polyps, may be caused by sexual reproduction in a degraded reef environment. Understanding these reproductive traits may be useful for predicting the resiliency of populations of L. schoedei in response to ongoing and future environmental change.
- Two hidden mtDNA-clades of crown-of-thorns starfish in the Pacific OceanYasuda, Nina; Inoue, Jun; Hall, Michael R.; Nair, Manoj R.; Adjeroud, Mehdi; Fortes, Miguel D.; Nishida, Mutsumi; Tuivavalagi, Nat; Ravago-Gotanco, Rachel; Forsman, Zac H.; Soliman, Taha; Koyanagi, Ryo; Hisata, Kanako; Motti, Cherie A.; Satoh, Noriyuki (Frontiers Media SA, 2022-04-27)Recurring outbreaks of crown-of-thorns starfish (COTS) severely damage healthy corals, especially in the Western Pacific Ocean. To obtain a better understanding of population genetics of COTS and historical colonization across the Pacific Ocean, complete mitochondrial genomes were sequenced from 243 individuals collected in 11 reef regions. Our results indicate that Pacific COTS (Acanthaster cf. solaris) comprise two major clades, an East-Central Pacific (ECP) clade and a Pan-Pacific (PP) clade, separation of which was supported by high bootstrap value. The ECP clade consists of COTS from French Polynesia, Fiji, Vanuatu and the Great Barrier Reef (GBR). The Hawaii population is unique within this clade, while California COTS are included in EPC clade. On the other hand, the PP clade comprises multiple lineages that contain COTS from Vietnam, the Philippines, Japan, Papua New Guinea, Micronesia, the Marshall Islands, GBR, Vanuatu, Fiji and French Polynesia. For example, a lineage of the PP clade, which has the largest geographic distribution, includes COTS from all of these locations. These results suggest two alternative histories of current geographic distributions of COTS in the Pacific Ocean, an ECP clade ancestry or Western Pacific clade ancestry. Although further questions remain to be explored, this discovery provides an evolutionary context for the interpretation of COTS population structure which will aid future coral reef research in the Pacific Ocean, and ultimately improve reef management of COTS.We thank the following people for their help with sample collection: Dr. Hugh Sweatman and the AIMS Bioresources Library for GBR samples, Dr. Molly Timmers for Hawaiian samples, Geoff Jones and Jeff Kinch for Papua New Guinean samples, Monal Lal for Fijian samples, Christina Shaw for Vanuatu samples, Hoang Dinh Chieu for Vietnamese samples, and Hiromitsu Ueno for Japanese samples. The DNA Sequencing Section and IT section of OIST are acknowledged for its expert help with genome sequencing and bioinfomatic analysis. Last, but not least, we acknowledge the traditional owners of the lands and sea country on which this research took place.
- Reproductive biology and early life history of the solitary coral Heliofungia actiniformis from Singapore and the PhilippinesSayco, Sherry Lyn G; Prasetia, Rian; Todd, Peter A.; Loya, Yossi; Valencia, Brian; Calle, Lala Grace; Cabaitan, Patrick C. (Springer, 2024-01-13)Reproduction and early life history are central to understanding the biology and ecology of organisms, however such information is limited for solitary corals. Here, we compared the reproductive traits of the solitary coral Heliofungia actiniformis from different latitudinal locations (Singapore, 1°N and the Philippines, 16°N) and examined their early life development, settlement competency, and juvenile growth and survival. A total of 32 corals from Pulau Hantu reefs in Singapore and 102 corals from Bolinao and Anda reefs in the Philippines were studied between 2019 and 2022. Heliofungia actiniformis broadcasts spawned gametes during several nights, generally between 22:00 and 01:00, before and after full moon, from February to May in Singapore and from March to June in the Philippines. Spawning within a month occurred for up to 16 nights in Singapore and 10 nights in the Philippines. Sex change in two individuals between years was observed in the Philippines. The average egg size was smaller in Singapore than that in the Philippines. We determined that eggs were fertilized within 2 h after sperm addition, and developed into swimming larvae within 64 h, which began to settle after 24 h. Larval survival after three mo of culture was 1.72 ± 1.0% and juvenile diameter ranged from 0.33 to 1.30 mm. Asexual buds were first observed in 15 mo old juveniles that were at least 8 mm in diameter. 24 mo old juveniles were observed to detach from their stalk and the empty stalk regenerated polyps. Our results highlight the latitudinal variability in the reproductive traits of solitary corals, serve as a baseline for their early life history, and advance our understanding of their population dynamics.