Kawamura Iori, Jamodiong Emmeline A, Reimer James Davis
Molecular Invertebrate Systematics and Ecology Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan.
Molecular Invertebrate Systematics and Ecology Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan,
Zoolog Sci. 2022 Oct;39(5):477-488. doi: 10.2108/zs220027.
Among family Zoanthidae (Anthozoa: Hexacorallia: Zoantharia), and are widespread benthos on coral reefs, but the reproductive biology of both genera is generally unknown. Accordingly, sexual reproduction of two Zoanthidae species in Japan, in Okinawa, and in Okinawa and Kochi, was investigated by annual sampling. Between 2012 and 2013, polyps of tagged colonies of and were sampled monthly, and gonads in mesenteries were examined under a stereomicroscope. In , sizes of oocytes were estimated and in situ spawning observations were conducted at night at Okinawa sites. Monthly sampling indicated that gametogenesis periods of both species in Okinawa were from May to August, and oogenesis set in earlier than spermatogenesis, and thus both species can be considered protogynous functional hermaphrodites. On the other hand, in Kochi had hermaphroditic polyps in July and August. Notably, fertile colonies of were not only hermaphrodites but also included exclusively male and female colonies. Overall, four sexual types were identified in : male, female, functional protogynous hermaphrodites, and unclassified sterile colonies. In situ gamete release of was observed in August 2012 and July to August 2013. First spawning of the year occurred 1 day after the new moon; colonies shed their bundles 3.5-4 h after sunset. We speculate that lunar phase and time after sunset influence spawning timing in . Basic knowledge on sexual reproduction of Zoanthidae is critically needed to better understand the basic biology of these benthic cnidarians.
在群体海葵科（珊瑚纲：六放珊瑚亚纲：群体海葵目）中，它们是珊瑚礁上广泛分布的底栖生物，但这两个属的生殖生物学通常尚不为人所知。因此，通过年度采样对日本冲绳县的两种群体海葵科物种以及冲绳县和高知县的另一种群体海葵科物种的有性生殖进行了研究。在2012年至2013年期间，每月对标记群体的海葵息肉进行采样，并在体视显微镜下检查肠系膜中的性腺。对于一种海葵，估计了卵母细胞的大小，并在冲绳的地点夜间进行了原位产卵观察。每月采样表明，冲绳的这两种物种的配子发生期均为5月至8月，卵子发生比精子发生更早开始，因此这两种物种都可被视为雌性先熟的功能性雌雄同体。另一方面，高知县的另一种海葵在7月和8月有雌雄同体的息肉。值得注意的是，该种的可育群体不仅是雌雄同体，还包括纯雄性和纯雌性群体。总体而言，在该种中鉴定出了四种性类型：雄性、雌性、功能性雌性先熟雌雄同体和未分类的不育群体。在2012年8月以及2013年7月至8月观察到了该种的原位配子释放。当年的首次产卵发生在新月后的第1天；群体在日落3.5 - 4小时后排出配子束。我们推测月相和日落后的时间会影响该种的产卵时间。为了更好地理解这些底栖刺胞动物的基础生物学，迫切需要关于群体海葵科有性生殖的基础知识。
