Bazsalovicsová Eva, Králová-Hromadová Ivica, Brabec Jan, Hanzelová Vladimíra, Oros Mikulás, Scholz Tomás
Folia Parasitol (Praha). 2014 Aug;61(4):347-54.
Molecular analysis of an extensive specimen collection of morphologically distinct tapeworms of the genus Caryophyllaeus Gmelin, 1790 (Cestoda: Caryophyllidea), parasites of cyprinid fishes in the Palaearctic Region, brought evidence of host-related plasticity in critical morphological characters widely used for species circumscription and classification of these tapeworms. The results obtained here do not support the traditionally used morphological concept of species-defining characters of the order Caryophyllidea Carus, 1863, especially due to high morphological plasticity of the scolex and the anterior end of the body. Several morphotypes within both Caryophyllaeus laticeps (Pallas, 1781) and Caryophyllaeus brachycollis Janiszewska, 1953 generally corresponding to different hosts and geographical regions, were recognised likely suggesting host- and geography-related intraspecific morphological variability. Genetic data confirmed euryxenous host specificity of both species, most profoundly C. laticeps, but did not support the existence of cryptic species. In fact, some of the fish hosts may harbour both of the congeneric species including several of their respective morphotypes. The pattern of morphological and genetic divergence observed in both cestode species studied indicates a scenario of possible host range extensions and subsequent parasite diversification. If molecular sequence variability and host-related morphological polymorphism are confirmed in other groups of monozoic cestodes, it may complicate species identification and straightforward classification of these parasites.
对1790年格梅林属（Caryophyllaeus Gmelin）形态各异的绦虫大量标本进行分子分析，这些绦虫是古北区鲤科鱼类的寄生虫，结果表明，在广泛用于这些绦虫物种界定和分类的关键形态特征中存在宿主相关可塑性。此处获得的结果不支持1863年卡鲁斯（Carus）提出的传统上用于界定卡里ophyllidea目物种特征的形态学概念，特别是由于头节和虫体前端具有高度的形态可塑性。在宽头格梅林绦虫（Caryophyllaeus laticeps，帕拉斯，1781年）和短颈格梅林绦虫（Caryophyllaeus brachycollis，贾尼谢夫斯卡，1953年）中识别出了几种形态型，它们通常对应于不同的宿主和地理区域，这可能表明存在与宿主和地理相关的种内形态变异。遗传数据证实了这两个物种具有广宿主特异性，其中宽头格梅林绦虫最为明显，但不支持隐存种的存在。事实上，一些鱼类宿主可能同时寄生这两个同属物种，包括它们各自的几种形态型。在所研究的两种绦虫物种中观察到的形态和遗传分歧模式表明，可能存在宿主范围扩展和随后寄生虫多样化的情况。如果在其他单殖绦虫类群中证实了分子序列变异性和与宿主相关的形态多态性，可能会使这些寄生虫的物种鉴定和直接分类变得复杂。
