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# A phylogenetic analysis of Gammarus species (Crustacea: Amphipoda, Gammaridae) from Iran, with description of a new species

## Details

**Authors** Alimohammadi et al.

**Year** 2026

**Publisher** Zootaxa

**Discipline** Evolutionary Biology

[Read it at the publisher](https://doi.org/10.11646/zootaxa.5857.3.5) 
10.11646/zootaxa.5857.3.5

## In authors' words

### Abstract

An amphipod, Gammarus ardakanensis sp. nov. is described from the Malkoh Village, Yazd Province, Iran using both morphological and molecular data. This species is distinguished from other species by a combination of characters: antenna II gland cone of peduncular article 2 shorter than article 3; peduncles and flagellum of antenna II densely setose; calceoli absent on antenna II; outer margin of second palpar article in maxilla I with numerous short simple setae; posterior margins of merus and carpus of pereopods III–IV with long setae; coxal plate V bearing one robust seta on posterior margin; inner ramus of uropod III approximately 0.78 times of outer ramus; and both rami of uropod III with plumose setae on outer and inner margins. Phylogenetic analysis using 28S rRNA and COI gene sequences confirmed the species distinctness. A distribution map for Iranian species is provided.

### What they found (results)

The authors describe a new amphipod species, Gammarus ardakanensis, from Yazd Province, Iran, delimiting it from congeners using antenna and pereopod morphology and confirming the boundary with 28S rRNA and COI phylogenetic analysis.

## Commentary

### In short

Drawing a species boundary is a distinction — fixing what an entity is against what it is not. The boundary is then confirmed by relationship: where the animal sits on a phylogeny relative to its congeners.

**Patterns it shows** D, S

**Added** 2026-08-03

**How to cite this** Alimohammadi et al. (2026). A phylogenetic analysis of Gammarus species (Crustacea: Amphipoda, Gammaridae) from Iran, with description of a new species. Zootaxa.