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Issue: Vol. 5862 No. 1: 4 Aug. 2026
Type: Article
Published: 2026-08-04
DOI: 10.11646/zootaxa.5862.1.5
Page range: 127-144
Abstract views: 346
PDF downloaded: 351

Resurrection and redescription of Hyalella fluvialis (Harford, 1877) (Amphipoda: Hyalellidae), with notes on its distribution and conservation

Department of Biology; Miami University; Oxford; OH 45056; USA
US Bureau of Land Management; Southern Nevada District Office; Las Vegas; NV 89130; USA
Department of Biology; Miami University; Hamilton; OH 45011; USA
Crustacea San Francisco California Bay Area

Abstract

Molecular and morphological analyses targeting Hyalella fluvialis (Harford, 1877), a freshwater amphipod species which was synonymized with Hyalella azteca (Saussure, 1858), reveal the former to not be a junior subjective synonym of the latter. The species is resurrected and redescribed here based on freshly collected topotypes. Both lines of evidence clearly identify the species as distinct when compared to other members of the genus. Based on results of our four-locus molecular phylogenetic analysis, H. fluvialis appears to possess a constrained distribution along the California coast, likely restricted to the San Francisco Bay area. Although only collected from two sites in Marin and San Francisco counties, observations outside this area report the presence of another species which replaced H. fluvialis in central California, consistent with a restricted distribution for H. fluvialis. Our results suggest that H. fluvialis may be similar in distribution to other bay area freshwater endemics which are currently of conservation concern. As a result, it is likely that H. fluvialis may also warrant conservation attention; further examination is needed to confirm its distribution and the threats it may be facing.

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How to Cite

Cannizzaro, A.G., Lange, C.J. & Berg, D.J. (2026) Resurrection and redescription of Hyalella fluvialis (Harford, 1877) (Amphipoda: Hyalellidae), with notes on its distribution and conservation. Zootaxa, 5862 (1), 127–144. https://doi.org/10.11646/zootaxa.5862.1.5