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Orejas C, Antón-Sempere S, Terrón-Sigler A, Grau A. Reproductive characteristics and gametogenic cycle of the scleractinian coral Dendrophyllia ramea. PeerJ 2023; 11:e16079. [PMID: 37790618 PMCID: PMC10544315 DOI: 10.7717/peerj.16079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/21/2023] [Indexed: 10/05/2023] Open
Abstract
The present study marks a pioneering investigation into the reproductive cycle of the scleractinian coral Dendrophyllia ramea. This is one of the first reproduction studies conducted in the Mediterranean Sea for a colonial azooxanthellate coral. Coral samples were collected in 2017 (May and October) and 2018 (February and July) in the Alborán Sea (SW Mediterranean). This location was selected due to its rarity as one of the few sites where this species thrives at depths shallower than 40 m. These samples were used to study the sexual patterns, fertilization mechanisms and gametogenic cycles by means of histological techniques. To broaden the scope, Sea Surface Temperature (SST) and Chlorophyll-a (Chl-a) data from open access databases have been considered to explore the potential influence of these environmental factors as triggers for gamete development and spawning time. The findings cast D. ramea as a gonochoric species, since no hermaphroditic specimens were observed among the analysed samples. Additionally, the lack of larvae and embryos in any of the analysed polyps, suggest that this species is fertilised externally. Two oocyte cohorts have been detected simultaneously, hinting at a yearly reproductive cycle, characterised by a prolonged oocyte maturation and seasonal spawning period taking place between August and October. Nevertheless, D. ramea display a low fecundity compared to other scleractinians inhabiting deep waters. Lastly, the early stages of gametogenesis seem to be coupled with the highest Chl-a values (i.e., March and December), whereas spawning takes place throughout the warmest period of the year (August to October).
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Affiliation(s)
- Covadonga Orejas
- Centro Oceanográfico de Gijón, Spanish Institute of Oceanography (IEO-CSIC), Gijón, Asturias, Spain
| | - Silvia Antón-Sempere
- Centro Oceanográfico de Baleares, Spanish Institute of Oceanography (IEO-CSIC), Palma, Baleares, Spain
- Laboratorio de Investigaciones Marinas y Acuicultura (LIMIA, IRFAP), Gobierno de las Islas Baleares, Puerto de Andratx, Baleares, Spain
| | | | - Amalia Grau
- Laboratorio de Investigaciones Marinas y Acuicultura (LIMIA, IRFAP), Gobierno de las Islas Baleares, Puerto de Andratx, Baleares, Spain
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Sentoku A, Shimizu K, Naka T, Tokuda Y. Dimorphic life cycle through transverse division in burrowing hard coral Deltocyathoides orientalis. Sci Rep 2022; 12:9359. [PMID: 35672351 PMCID: PMC9174229 DOI: 10.1038/s41598-022-13347-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/23/2022] [Indexed: 11/21/2022] Open
Abstract
The azooxanthellate solitary scleractinian Deltocyathoides orientalis (family Turbinoliidae), which has bowl-shaped costate corallites, exhibits burrowing behavior on soft substrates and can adapt to an infaunal mode of life. Here, we describe previously unknown aspects of their life history and asexual mode of reproduction based on morphological and molecular phylogenetic analyses. The findings reveal that (1) D. orientalis exhibits asexual reproduction by transverse division; (2) smaller bowl-shaped costate anthocyathus derived from cylindrical to tympanoid anthocaulus were attached to hard substrates, including shell fragments and gravels on soft substrates; and (3) anthocyathus only reproduce sexually after division, and anthocaulus was found to regrow and repeatedly produce anthocyathi through transverse division. The bowl-shaped corallum morphology of the anthocyathus just after division might reduce the time required for skeletal formation to enable infaunal adaption after transverse division. Immediately after division, D. orientalis can smoothly shift to a burrowing lifestyle that efficiently utilizes soft-substrate environments, thus increasing its survival rate. The morphological formation of prospective anthocyathus in the anthocaulus stage is consequently thought to involve an increase in clonal individuals as well as adaptations for a burrowing free-living mode of life in the anthocyathus stage.
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Affiliation(s)
- Asuka Sentoku
- Department of Physics and Earth Sciences, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan.
| | - Keisuke Shimizu
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| | - Tsubasa Naka
- Department of Physics and Earth Sciences, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan
| | - Yuki Tokuda
- Tottori University of Environmental Studies, 1-1-1 Wakabadaikita, Tottori, 689-1111, Japan
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Pendleton A, Hartill E, Waller R. Notes on reproduction in the deep-sea cup coral Balanophyllia malouinensis (Squires 1961) from the Southern Ocean. Polar Biol 2021. [DOI: 10.1007/s00300-021-02854-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Exaiptasia diaphana from the great barrier reef: a valuable resource for coral symbiosis research. Symbiosis 2020. [DOI: 10.1007/s13199-020-00665-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Okubo N. Restructuring the Traditional Suborders in the Order Scleractinia Based on Embryogenetic Morphological Characteristics. Zoolog Sci 2016; 33:116-23. [PMID: 26853877 DOI: 10.2108/zs150094] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The order Scleractinia includes two distinct groups, which are termed "complex" and "robust" as indicated by the molecular phylogeny of mitochondrial 16S ribosomal gene sequences. Since this discovery, coral taxonomists have been seeking morphological characters for grouping this deep division in the order Scleractinia. Recently, morphological characteristics during embryogenesis that facilitate grouping the two clades as "complex" and "robust" were reported, thus clarifying a deep division in the Scleractinia. In the present report, I establish two new suborders, Refertina and Vacatina, on the basis of the embryogenetic morphological characteristics, molecular data, and new observations of Tubastraea coccinea and Cyphastrea serailia embryogenesis. In particular, the embryo of T. coccinea has a possible fertilization membrane that was first observed in the phylum Cnidaria. The new suborder Refertina consists of the families that belong to the "complex" clade and have no or little blastocoel. The new suborder Vacatina is composed of the families that fall into the "robust" clade and have an apparent blastocoel.
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Affiliation(s)
- Nami Okubo
- Department of Economics, Tokyo Keizai University, 1-7-34 Minamimachi, Kokubunji, Tokyo 185-8502, Japan
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Tsai S, Chang WC, Chavanich S, Viyakarn V, Lin C. Ultrastructural observation of oocytes in six types of stony corals. Tissue Cell 2016; 48:349-55. [PMID: 27265208 DOI: 10.1016/j.tice.2016.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 05/19/2016] [Accepted: 05/20/2016] [Indexed: 11/25/2022]
Abstract
In this study, the ultrastructure of the oocytes of 6 types of scleractinian corals was observed by transmission electron microscopy (TEM). Moreover, histological and ultrastructural analyses were performed to improve our understanding of the organelles involved in coral oocyte formation. In all 6 stony coral species, the microvilli were tubular and directly grew from the surface of the oocyte membrane; yolk bodies, lipid granules, and cortical alveoli accounted for most of the volume inside the oocytes, suggesting that they are associated with energy storage and buoyancy. Clear differences were observed in the size of yolk bodies and lipid granules in the oocytes of the 6 stony coral species, which occupied approximately 55%-80% of the inner space of the oocytes. Galaxea fascicularis exhibited the largest lipid granule volume, but the oocytes contained only an average number of 12.45 lipid granules per unit area. Only Montipora incrassata oocytes contained symbiotic algae. The smallest size and proportion of lipid granules in M. incrassata oocytes may be attributed to the presence of symbiotic algae and large yolk bodies, which may help oocytes produce energy and function as a nutritional source. This study is crucial for improving the understanding of the basic biology of coral reproduction, and the ensuing datasets is critical for conservation-oriented studies seeking to cryopreserve corals during these times of dramatic global climate change.
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Affiliation(s)
- Sujune Tsai
- Department of Biotechnology, Mingdao University, Peetow, Chang Hua, Taiwan; Department of Post Modern Agriculture, Mingdao University, Peetow, Chang Hua, Taiwan
| | - Wei-Chieh Chang
- Institute of Marine Biology, National Dong Hwa University, Checheng, Pingtung, Taiwan
| | - Suchana Chavanich
- Reef Biology Research Group, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Voranop Viyakarn
- Reef Biology Research Group, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Chiahsin Lin
- National museum of Marine Biology & Aquarium, Checheng, Pingtung, Taiwan; Institute of Marine Biology, National Dong Hwa University, Checheng, Pingtung, Taiwan.
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Marchini C, Airi V, Fontana R, Tortorelli G, Rocchi M, Falini G, Levy O, Dubinsky Z, Goffredo S. Annual Reproductive Cycle and Unusual Embryogenesis of a Temperate Coral in the Mediterranean Sea. PLoS One 2015; 10:e0141162. [PMID: 26513159 PMCID: PMC4625958 DOI: 10.1371/journal.pone.0141162] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 10/04/2015] [Indexed: 11/18/2022] Open
Abstract
The variety of reproductive processes and modes among coral species reflects their extraordinary regeneration ability. Scleractinians are an established example of clonal animals that can exhibit a mixed strategy of sexual and asexual reproduction to maintain their populations. This study provides the first description of the annual reproductive cycle and embryogenesis of the temperate species Caryophyllia inornata. Cytometric analyses were used to define the annual development of germ cells and embryogenesis. The species was gonochoric with three times more male polyps than female. Polyps were sexually mature from 6 to 8 mm length. Not only females, but also sexually inactive individuals (without germ cells) and males were found to brood their embryos. Spermaries required 12 months to reach maturity, while oogenesis seemed to occur more rapidly (5–6 months). Female polyps were found only during spring and summer. Furthermore, the rate of gamete development in both females and males increased significantly from March to May and fertilization was estimated to occur from April to July, when mature germ cells disappeared. Gametogenesis showed a strong seasonal influence, while embryos were found throughout the year in males and in sexually inactive individuals without a defined trend. This unusual embryogenesis suggests the possibility of agamic reproduction, which combined with sexual reproduction results in high fertility. This mechanism is uncommon and only four other scleractinians (Pocillopora damicornis, Tubastraea diaphana, T. coccinea and Oulastrea crispata) have been shown to generate their broods asexually. The precise nature of this process is still unknown.
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Affiliation(s)
- Chiara Marchini
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Valentina Airi
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Roberto Fontana
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Giada Tortorelli
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Marta Rocchi
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
| | - Giuseppe Falini
- Department of Chemistry “G. Ciamician”, University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Oren Levy
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Zvy Dubinsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Stefano Goffredo
- Marine Science Group, Department of Biological, Geological and Environmental Sciences, University of Bologna, Via F. Selmi 3, 40126 Bologna, Italy
- * E-mail:
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Reproductive efficiency of a Mediterranean endemic zooxanthellate coral decreases with increasing temperature along a wide latitudinal gradient. PLoS One 2014; 9:e91792. [PMID: 24618568 PMCID: PMC3950289 DOI: 10.1371/journal.pone.0091792] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 02/13/2014] [Indexed: 11/30/2022] Open
Abstract
Investments at the organismal level towards reproduction and growth are often used as indicators of health. Understanding how such energy allocation varies with environmental conditions may, therefore, aid in predicting possible responses to global climatic change in the near future. For example, variations in seawater temperature may alter the physiological functioning, behavior, reproductive output and demographic traits (e.g., productivity) of marine organisms, leading to shifts in the structure, spatial range, and abundance of populations. This study investigated variations in reproductive output associated with local seawater temperature along a wide latitudinal gradient on the western Italian coast, in the zooxanthellate Mediterranean coral, Balanophyllia europaea. Reproductive potential varied significantly among sites, where B. europaea individuals from the warmest site experienced loss of oocytes during gametogenesis. Most of the early oocytes from warmest sites did not reach maturity, possibly due to inhibition of metabolic processes at high temperatures, causing B. europaea to reabsorb the oocytes and utilize them as energy for other vital functions. In a progressively warming Mediterranean, the efficiency of the energy invested in reproduction could be considerably reduced in this species, thereby affecting vital processes. Given the projected increase in seawater temperature as a consequence of global climate change, the present study adds evidence to the threats posed by high temperatures to the survival of B. europaea in the next decades.
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