Unio, a freshwater mussel genus, has a low number of species in Tunisia, among them U. durieui, which is categorised as Endangered for conservation in IUCN Red List. The purpose of the study was to investigate morphological similarity and genetic relationships between samples of the genus Unio collected from rivers of the Ichkeul watershed. The collection includes three samples of U. ravoisieri, a single sample of U. durieui and a sample morphologically distinct from the first two, which could be a new ‘species’ discovered in the sampling area. Principal components analysis, based on eight morphological traits, separated the samples into three groups according to the ‘species’ and the variant form was found morphologically closer to U. ravoisieri than U. durieui. Analysis of genetic diversity has defined an extensive allozyme monomorphism. The Nei’s standard genetic distance between U. ravoisieri and U. durieui, ranges from 0.5330 to 0.5881 and F_ST values vary between 0.93 and 0.98 and are highly significant. However, the genetic comparison between the variant form and U. ravoisieri samples showed no significant difference in allele and genotype frequencies, which supports the hypothesis that the new form is a phenotype of U. ravoisieri and not a separate species.

Unio是一种淡水贻贝属，在突尼斯的物种数量很少，其中U. durieui属于IUCN红色名录中的濒危物种。这项研究的目的是调查形态相似性和属的样本之间的基因关系珠蚌从伊其克乌尔的河流流域收集。该集合包括三个U. ravoisieri样本，一个U. durieui样本样本在形态上与前两个样本不同，这可能是在采样区域发现的一个新“物种”。主成分分析，基于8个形态特征，根据“物种”和变体形式形态接近发现分离出的样品分为三组U. ravoisieri比U. durieui。遗传多样性分析已定义了广泛的同工酶单态性。Nei在U. ravoisieri和U. durieui之间的标准遗传距离范围为0.5330至0.5881，F _ST值在0.93至0.98之间变化，并且非常显着。然而，变异形式和U. ravoisieri之间的遗传比较样品显示等位基因和基因型频率没有显着差异，这支持了新形式是U. ravoisieri的表型而不是独立物种的假设。