The species composition and structure of bottom communities with a predominance of bivalve mollusks of the Portlandia genus, which are widespread on the shelf of the Russian Arctic, were analyzed. Molecular genetic analysis confirmed that Portlandia aestuariorum and P. arctica are valid species; it has been shown that all P. arctica from different regions belong to the same species regardless their morphological variations. Ten different variants of benthic communities from the White, Kara, Laptev, and East Siberian seas were described, in which P. aestuariorum and P. arctica play the dominant role. No associated species complexes have been identified for Portlandia spp. Communities practically do not have common species, and their composition and structure are determined by the selection of species with similar ecological preferences from the local fauna. The differences in communities are determined by both geographical and environmental factors.

中文翻译：

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北极地区以波特兰迪亚为主的社区：沿地理梯度的分类组成和结构

分析了在俄罗斯北极大陆架上广泛分布的波特兰属双壳软体动物占优势的底层群落的物种组成和结构。分子遗传分析证实Portlandia aestuariorum和P. arctica为有效种；已经表明，来自不同地区的所有 P. arctica 都属于同一物种，无论它们的形态变化如何。描述了来自怀特海、喀拉海、拉普捷夫海和东西伯利亚海的十种不同的底栖群落变体，其中 P. aestuariorum 和 P. arctica 起主导作用。尚未鉴定出波特兰属的相关物种复合体。社区实际上没有共同的物种，它们的组成和结构是由从当地动物群中选择具有相似生态偏好的物种决定的。社区的差异是由地理和环境因素共同决定的。