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National Committee on Marine Sciences (NCMS)

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    A unique reproductive strategy in the mushroom coral Fungia fungites
    Eyal-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.
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    Reproductive phenology and morphology of Macrocystis pyrifera (Laminariales, Ochrophyta) from southern New Zealand in relation to wave exposure1
    Leal, Pablo P.; Roleda, Michael Y.; Fernández, Pamela A.; Nitschke, Udo; Hurd, Catriona L. (Wiley, 2021-07-23)
    Macrocystis pyrifera is a major habitat forming kelp in coastal ecosystems of temperate regions of the northern and southern hemispheres. We investigated the seasonal occurrence of adult sporophytes, morphological characteristics, and reproductive phenology at two sites within a wave-protected harbour and two wave-exposed sites in southern New Zealand every 3–4 months between 2012 and 2013. Seasonality in reproduction was assessed via the number of sporophylls, the occurrence of sori on sporophylls, and non-sporophyllous laminae (fertile pneumatocyst-bearing blades and fertile apical scimitars), meiospore release, and germination. We found that M. pyrifera was present and reproductive year-round in three of the four sites, and patterns were similar for the wave-exposure conditions. Sori were found on pneumatocyst-bearing blades and apical scimitars in addition to the sporophylls, and viable meiospores were released from all three types of laminae. Morphological variations between sites with different wave exposure indicate that sporophytes from wave-protected sites have bigger blades and holdfasts and are longer than those from wave-exposed sites. We discuss the implications of these biological variables for the ecology of M. pyrifera inhabiting different wave exposure environments in southern New Zealand.
    Pablo P. Leal was supported by a scholarship from BECAS CHILE-ANID and by Programa Integral de Desarrollo de Acuicultura de Algas para Pescadores Artesanales (Etapa 4), funded by the Subsecretarıa de Economıa y Empresas de Menor Tamano (Convenio 2016). Michael Y. Roleda acknowledges the Philippine’s Department of Science and Technology (DOST) Balik Scientist Program for the fellowship. Udo Nitschke gratefully acknowledges support by Skidmore College, 815 North Broadway, Saratoga Springs, NY 12866, USA. Pamela A. Fernandez was supported by the Chilean National Commission for Scientific and Technological Research (ANID/FONDECYT; Postdoctoral grant 3170225 and grant 1180647) and ANID/Programa Basal (CeBiB, FB-0001). We are grateful to Rocio Suarez for assisting in field sampling.
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    Reproductive biology and early life history of the solitary coral Heliofungia actiniformis from Singapore and the Philippines
    Sayco, 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.
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    Contrasting reproductive strategies between stress-tolerant and competitive coral taxa
    Bonilla, K. G.; Guest, J. R.; Baria-Rodriguez, M. V. (Springer, 2023-04-19)
    Reproductive traits such as fecundity (i.e., the number of gametes produced) and the size and age of coral colonies at reproductive onset can vary in predictable ways among life history strategies. However, most studies on the onset of reproductive maturity in corals only report the presence or absence of oocytes with little known about variation in fecundity across size and age classes. This study aimed to determine the colony size and fecundity at the onset of reproductive maturity across size classes of two scleractinian corals with contrasting life history strategies, Acropora millepora (competitive) and Favites colemani (stress-tolerant). Colonies at a site in northwestern Philippines were sampled to determine the smallest colony size class with mature oocytes and to estimate fecundity across size classes. Histological slides were also prepared to verify the presence of mature gametes. Colonies were able to produce mature oocytes when they had attained colony diameters of 4.7 cm for A. millepora and 1.5 cm for F. colemani. A. millepora had lower fecundity, but larger oocytes compared to F. colemani. Although small colonies can contribute to the larval pool, the proportion of mature colonies increased for larger size classes, suggesting that larger colonies make a disproportionately greater contribution to population reproductive output. These findings contribute to our understanding of coral population dynamics, particularly in parameterizing population and demographic models for different coral life histories.
    We are grateful to Christine Baran, Jue Alef Lalas, Jerry Arboleda, Gabriel de Guzman, the students and research assistants of Community and Ecology and Interactions of Marine Bionts and Benthic Ecosystems Laboratories for their valuable assistance during field and laboratory works, Darryl Valino for the site map, and Liam Lachs for the assistance on the statistical analyses. This research was supported by the University of the Philippines Marine Science Institute’s In-house project, Department of Science and Technology – ASTHRDP Thesis Grant, and University of the Philippines – Office of the Vice President for Academic Affairs’ Balik Ph.D. project (OVPAA-BPhD-2018-02).