Theoretical size at the onset of maturity (TSOM) for female Norway lobster was estimated by a new methodology based on the probability distributions of mature individuals built on physiological maturity measures. Onset of maturity using TSOM varied from 18.4- to 33.7-mm carapace length for the Irish functional management units (FUs). These estimates showed a significant negative linear relationship (R2 = 0.60) with population density and a significant positive linear relationship with average size in females (R2 = 0.84). The size class at which 50% of the females are sexually mature (L50) was linked to the new TSOM metric by a significant positive linear relationship (R2 = 0.40). This set of linear relationships ultimately allowed TSOM and L50 to be estimated without a requirement for maturity stages to be distinguished. As well as contributing to the stock assessment and management of Nephrops (e.g. in data-limited FUs) and its potential for the calibration of more routinely used estimates, TSOM might be applied in new species and meta-analyses where size of maturity data are scarce. This new metric also better-defines the maturity process since, taken together, TSOM, L50, and smallest berried female represent sequential maturity events: (i) onset of maturity, (ii) 50% mature (from gonad staging), and (iii) berried females.

中文翻译：

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成熟开始时的理论大小及其与密度相关的可变性作为甲壳类渔业管理的一种选择

雌性挪威龙虾在成熟开始时的理论大小 (TSOM) 是通过一种新方法估计的，该方法基于基于生理成熟度测量的成熟个体的概率分布。爱尔兰功能管理单位 (FUs) 使用 TSOM 的成熟开始时间从 18.4 到 33.7 毫米不等。这些估计值与人口密度呈显着负线性关系（R2 = 0.60），与女性平均体型呈显着正线性关系（R2 = 0.84）。50% 的女性性成熟 (L50) 的大小等级与新的 TSOM 指标通过显着的正线性关系 (R2 = 0.40) 相关联。这组线性关系最终允许在不需要区分成熟度阶段的情况下估计 TSOM 和 L50。除了有助于对 Nephrops 的种群评估和管理（例如在数据有限的 FUs 中）及其校准更常规使用的估计值的潜力外，TSOM 还可应用于成熟度数据规模稀缺的新物种和荟萃分析. 这个新指标也更好地定义了成熟过程，因为综合起来，TSOM、L50 和最小的受精雌性代表了连续的成熟事件：(i) 成熟的开始，(ii) 50% 成熟（来自性腺分期），和（iii ) 受孕的雌性。