The growth and reproductive biology of the limpet Patella aspera were studied in the north-eastern Atlantic, Madeira archipelago, to enhance the knowledge concerning biological parameters and population dynamics of this species. This study comprised the estimation of growth rates, sexual maturity, reproduction, recruitment patterns, mortality coefficients and the exploitation rate, and yield-per-recruit (Y/R) based on monthly shell-length frequency data. A total of 16,941 specimens were sampled from January to December 2015. The relative growth pattern exhibited a negative allometric nature of growth for both sexes. The estimated von Bertalanffy growth parameters showed an asymptotic length of 84.15 mm for females and 80.51 mm for males with a growth coefficient of 0.36 and 0.32 year⁻¹ respectively. P. aspera in this geographical area is a moderately long-lived limpet with a predominance of specimens younger than 3 years old. This species is a winter breeder with a reproductive cycle encompassing three main periods namely development, spawning and resting with a synchronous gametogenesis for both sexes. Gonadal development lasts from October to December, spawning likely occurs from January until April and resting occurs from May to September. The mean size at sexual maturity was determined as 41.78 mm for females and 38.29 mm for males and the length at first capture as 42.62 mm. The recruitment pattern was continuous throughout the year with a major peak identified in March. The natural, fishing and total mortalities were similar between sexes, with fishing mortality exerting greatest pressure on this resource. However, yield-per-recruit analysis showed that the stock of P. aspera, in the study area, is exploited at levels below the fishing mortality that returns maximum sustainable yield. This study revealed that currently the stock of P. aspera is under-exploited, nonetheless due to it’s slow growth and long life, continuous monitoring and the enforcement of the existing harvest regulations must be accomplished if future over-exploitation is to be avoided. Further genetic studies are necessary to establish connectivity of the populations and improve present conservation strategies.

中文翻译：

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东北大西洋重点结石物种 Pat 蝶（Asella）的生长和繁殖 （软体动物：Patellogastropoda）

在东北大西洋马德拉群岛研究了 帽贝Pat蝶 的生长和生殖生物学 ，以增强有关该物种的生物学参数和种群动态的知识。这项研究包括根据月壳长频率数据估算增长率，性成熟度，生殖，招聘模式，死亡率系数和剥削率以及每招募产量（Y / R）。从2015年1月至2015年12月，总共采样了16941个标本。相对生长模式显示出两性生长的负异形性。估计的von Bertalanffy生长参数显示女性的渐近长度为84.15 mm，男性的渐近长度为80.51 mm，生长系数为0.36和0.32年^-1分别。 曲霉 在这个地理区域中，有一个中等寿命的帽贝，主要是3岁以下的标本。该物种是冬季繁殖者，其生殖周期包括三个主要时期，即两个性别的发育，产卵和静止配子发生。性腺发育持续时间从10月到12月，产卵的时间可能从1月到4月，而休息时间从5月到9月。雌性确定为性成熟时的平均大小为41.78 mm，雄性为38.29 mm，第一次捕获时的长度为42.62 mm。整个年度的招聘模式都是连续的，三月份出现了主要高峰。男女之间的自然死亡，捕鱼和总死亡率相似，捕鱼死亡率对该资源造成最大压力。然而， P.叶树， 研究区，在捕捞死亡，返回最大可持续产量水平低于利用。这项研究表明，尽管目前 P. aspera 的种群 开发不足，但由于其生长缓慢且寿命长，如果要避免将来的过度开发，必须完成持续的监测和执行现有的收获规定。为了建立种群之间的联系并改善目前的保护策略，有必要进行进一步的遗传研究。