In this paper, we investigated the age distribution and dynamics of polyps in the slow-growing and long-lived gorgonian Corallium rubrum (the Mediterranean red coral), applying an a posteriori demographic approach by considering each colony as a population of polyps. In the Mediterranean red coral, new polyps emerge from the coenenchyme in different regions of the colony and their budding rate depends on the age of branches. The age of polyps, branches and colonies were estimated using the organic-matter-staining dating method on thin sections of the colony skeleton. The median age and maximum life span of polyps were 4 and 12 years suggesting the presence of senescence processes: thus a colony renews several times its polyps during life cycle. Polyps were divided into annual age classes, and their mortality rates calculated. The polyp age distribution was then used to construct a mortality table and an algebraic transition matrix based on the age at death of 234 polyps. Finally, the polyp budding rate of a young, unbranched colony was calculated, and polyp temporal dynamics simulated. These findings represent the first steps for developing demographic models able to describe polyp dynamics of old and highly branched colonies.

中文翻译：

---

珍贵柳珊瑚的息肉寿命：暗示息肉动力学的人口统计学方法

在本文中，我们研究了生长缓慢且寿命长的红珊瑚（地中海红珊瑚）中息肉的年龄分布和动态，通过将每个菌落视为一个息肉种群来应用后验人口统计学方法。在地中海红珊瑚中，新的息肉从群落不同区域的同肉中出现，它们的出芽率取决于树枝的年龄。使用有机物染色定年法对菌落骨架的薄切片估计息肉、分支和菌落的年龄。息肉的中位年龄和最长寿命分别为 4 年和 12 年，表明存在衰老过程：因此，在生命周期中，一个菌落会更新数倍于其息肉。息肉被分为每年的年龄等级，并计算它们的死亡率。然后使用息肉年龄分布来构建死亡率表和基于 234 条息肉死亡年龄的代数转换矩阵。最后，计算了一个年轻的、未分枝的菌落的息肉出芽率，并模拟了息肉的时间动态。这些发现代表了开发能够描述旧的和高度分枝的菌落息肉动态的人口统计学模型的第一步。