One of the major problems in artificial eel reproduction is identification of broodstock with high performance reproductive characteristics. The aim of this study was to study population characteristics and the reproductive potential of eels (Anguilla anguilla) located in Valle Campo valley (Comacchio, Italy). A total of 200 eels/period (spring–summer and autumn–winter) were measured to obtain an external indicator of their maturation state. Morphometric parameters were used to calculate condition factor (K), eye index (EI) and pectoral fin length index (PFLI). Silver index analyses showed the lack of silver males and of fully mature females. Most represented females were yellow females at stage II. Silver females represented 27.9% of the population. Seasonal analysis shows how temperature reduction favoured the presence of silver females versus yellow females. Statistical analysis of EI, cranial (CI), PFLI and gonadosomatic (GSI) indexes showed that significant differences were found for EI, CI, PFLI and GSI between yellow and silver eels. No significant difference was found between stage III and IV silver eels, while a significant difference for EI was found between stage I and II yellow eels and for IC at stage II with respect to all other stages. The present study defined how Valle Campo could present environmental and trophic conditions which could favour precocious development of a population of silver females with a noticeable reproductive potential, to be used in open sea release or in artificial reproduction programmes. On the contrary, the valley seems to present unfavourable conditions for both development and sexual maturation of male eels.

人工鳗鱼繁殖的主要问题之一是鉴定具有高性能繁殖特征的亲鱼。这项研究的目的是研究位于Valle Campo山谷（意大利Comacchio ）的鳗鱼（Anguilla anguilla）的种群特征和繁殖潜力。总共测量了200个鳗鱼/时期（春季-夏季和秋季-冬季），以获取其成熟状态的外部指标。形态计量学参数用于计算条件因子（K），眼指数（EI）和胸鳍长度指数（PFLI）。白银指数分析显示，缺少男性银和完全成熟的女性。在第二阶段，大多数女性是黄色女性，银色女性占总人口的27.9％。季节性分析显示温度降低如何有利于银雌鱼和黄雌鱼的存在。EI，颅（CI），PFLI和性腺激素（GSI）指数的统计分析表明，黄e和白e之间的EI，CI，PFLI和GSI有显着差异。与其他所有阶段相比，在第三阶段和第四阶段银鳗之间没有发现显着差异，而在第一阶段和第二阶段黄鳗之间以及在第二阶段的IC中发现了EI的显着差异。本研究确定了Valle Campo如何呈现环境和营养条件，从而有利于具有显着繁殖潜力的白银雌性种群的早熟发育，可用于公海释放或人工繁殖计划。相反，该山谷似乎为雄性鳗鱼的发育和性成熟提供了不利条件。