Centro Oceanográfico de Gijón, Spanish Institute of Oceanography (IEO-CSIC), Gijón, Asturias, Spain.
Centro Oceanográfico de Baleares, Spanish Institute of Oceanography (IEO-CSIC), Palma, Baleares, Spain.
PeerJ. 2023 Sep 29;11:e16079. doi: 10.7717/peerj.16079. eCollection 2023.
The present study marks a pioneering investigation into the reproductive cycle of the scleractinian coral . 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 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, 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 (., March and December), whereas spawning takes place throughout the warmest period of the year (August to October).
本研究标志着对石珊瑚生殖周期的开创性调查。这是首次在地中海对无共生虫黄藻的群体珊瑚进行的繁殖研究之一。珊瑚样本于 2017 年（5 月和 10 月）和 2018 年（2 月和 7 月）在阿尔沃兰海（地中海西南部）采集。选择该地点是因为它是该物种在 40 米以下深度繁衍生息的少数几个稀有地点之一。这些样本用于通过组织学技术研究性模式、受精机制和配子发生周期。为了扩大范围，还考虑了来自开放访问数据库的海面温度 (SST) 和叶绿素-a (Chl-a) 数据，以探索这些环境因素作为配子发育和产卵时间触发因素的潜在影响。研究结果表明 是雌雄异体物种，因为在分析的样本中没有观察到雌雄同体的标本。此外，在任何分析的息肉中都没有发现幼虫和胚胎，这表明该物种是体外受精的。同时检测到两个卵母细胞群，暗示其具有每年的生殖周期，其特点是卵母细胞成熟时间延长，产卵期在 8 月至 10 月之间。然而，与栖息在深水中的其他石珊瑚相比， 显示出较低的繁殖力。最后，配子发生的早期阶段似乎与叶绿素-a 值最高（3 月和 12 月）相耦合，而产卵则发生在一年中最温暖的时期（8 月至 10 月）。
