Rezzag, HibaVillalobos-guerrero, Tulio F.Kurt, GuleyDenis, FrancoiseDaas, Tarek2025-03-232025-03-2320231108-393Xhttps://doi.org/10.12681/mms.33969https://hdl.handle.net/11486/5119This study uses morphological and molecular evidence to describe a new intertidal species of Perinereis Kinberg, 1865 (An-nelida: Nereididae) from northeast Algeria. Perinereis louizomarum n. sp. belongs to Subgroup 1A, which is distinguished by a single bar-shaped paragnath on area VI of the proboscis and a dorsal ligule that is either slightly or not expanded in the posterior parapodia. The new species differs from P. cultrifera and similar congeners by having a bare area V and slightly enlarged posterior dorsal ligules. Furthermore, using newly generated and mined sequences from online databases, and mined sequences of Perinere-is species from online, the analysis of cytochrome c oxidase subunit 1 (COI) mitochondrial gene sequences supported its status as new species. An identification key of the Perinereis species belonging to Subgroup 1A is also provided.eninfo:eu-repo/semantics/openAccessAlgeriadescriptionmtCOIPerinereis cultriferaSystematicsArticle24245446910.12681/mms.339692-s2.0-85168824552Q1WOS:001038377300002Q1