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Issue: Vol. 5799 No. 2: 28 Apr. 2026
Type: Article
Published: 2026-04-28
DOI: 10.11646/zootaxa.5799.2.7
Page range: 349-368
Abstract views: 45
PDF downloaded: 2

A new Tetranchyroderma species (Gastrotricha, Macrodasyida) from Tunisia, with its phylogenetic position based on molecular markers

University of Tunis El Manar; Faculty of Sciences of Tunis; LR18ES41 Laboratory of Ecology; Biology and Physiology of Aquatic Organisms; 2092; Tunis; Tunisia
University of Tunis El Manar; Faculty of Sciences of Tunis; LR18ES41 Laboratory of Ecology; Biology and Physiology of Aquatic Organisms; 2092; Tunis; Tunisia
University of Tunis El Manar; Faculty of Sciences of Tunis; LR18ES41 Laboratory of Ecology; Biology and Physiology of Aquatic Organisms; 2092; Tunis; Tunisia
Department of Life Sciences; University of Modena and Reggio Emilia; Via Giuseppe Campi; 213/D; 41125 Modena; Italy
Department of Life Sciences; University of Modena and Reggio Emilia; Via Giuseppe Campi; 213/D; 41125 Modena; Italy; National Biodiversity Future Center (NBFC); Piazza Marina 61; 90133 Palermo; Italy
Department of Earth and Marine Sciences; University of Palermo; Viale delle Science; 90128 Palermo; Italy
Department of Life Sciences; University of Modena and Reggio Emilia; Via Giuseppe Campi; 213/D; 41125 Modena; Italy; National Biodiversity Future Center (NBFC); Piazza Marina 61; 90133 Palermo; Italy
Gastrotricha biodiversity integrative taxonomy Mediterranean Sea meiofauna

Abstract

Data on marine gastrotrichs fauna from the southern coast of the Mediterranean Sea is scanty. To address the gap, a series of faunistic surveys along the northern Tunisian coastline is ongoing. In a shallow sublittoral sample collected at Chat Zwerâa, Béja, a new species of the genus Tetranchyroderma was found. Detailed morphological descriptions, along with molecular phylogenetic analysis based on ribosomal genes (18S and 28S) of the new species are provided. The new Tetranchyroderma has a pentancrous covering and prominent cephalic pestle organs; the caudal pedicles have three tubes each. The new species is also defined by a number and arrangement of adhesive tubes different from its congeners. Phylogenetic analyses using maximum likelihood (ML) and Bayesian inference (BI) methods, based on concatenated ribosomal gene sequences from 43 taxa, which included 31 thaumastodermatids, confirmed that the genus Tetranchyroderma is non-monophyletic. The analysis positioned the new species alongside other species that possess pestle organs, including Tetranchyroderma antenniphorum, T. esarabdophorum, T. papii and Ptychostomella tyrrhenica.

 

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How to Cite

Souid, A., Gammoudi, M., Cafsi, M.E., Cesaretti, A., Kosakyan, A., Saponi, F. & Todaro, M.A. (2026) A new Tetranchyroderma species (Gastrotricha, Macrodasyida) from Tunisia, with its phylogenetic position based on molecular markers. Zootaxa, 5799 (2), 349–368. https://doi.org/10.11646/zootaxa.5799.2.7