[DSRP Evidence](https://dsrpevidence.org/)

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

Alimohammadi et al., 2026, Zootaxa — Evolutionary Biology

Patterns: [Distinctions](https://dsrpevidence.org/pattern/distinctions), [Systems](https://dsrpevidence.org/pattern/systems)

## 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.

## 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.

## 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.

These researchers were not testing DSRP. The finding is theirs; the correspondence to DSRP is drawn by this site.

[Source](https://doi.org/10.11646/zootaxa.5857.3.5)