Hyalella azteca is a widespread and abundant species complex of amphipod crustacean in North America.

It reaches 3–8 mm (0.12–0.31 in) long, and is found in a range of fresh and brackish waters.

Hyalella azteca has body plan similar to most amphipods and is a classic freshwater example of the order.

[2] It is "the most abundant amphipod of lakes [in North America]",[3] with golf course ponds sometimes supporting large populations.

In contrast to other species of Hyalella, H. azteca is extremely common and has wide ecological tolerances.

[4] The main foodstuffs of H. azteca are filamentous algae and diatoms, although they may also consume organic detritus.

[1] It cannot assimilate either cellulose or lignin, even though these biomolecules are a major component of the leaf litter.

This does however conflict with their need to adapt to climate change: Fulton et al 2021 finds some of their mechanisms of resistance impose a fitness cost under higher temperatures.

Because of their wide distribution, ease of captive reproduction, and its niche in lake sediments, Hyalella azteca are used in aquatic toxicology assays in sediments [9] Hyalella azteca have been used to test bioaccumulation of different contaminants such as manufactured nanomaterials [1], pesticides [2], and metals [3].

[4] [5][6] Hyalella azteca was first described by Henri Louis Frédéric de Saussure in 1858, under the name Amphitoe aztecus, based on material collected by Aztecs[10] from a "cistern" near Veracruz, Mexico.

[13] H. azteca is now thought to represent a species complex, since there is little gene flow between populations, and different morphotypes are known to coexist in some areas.

Scientists looking to contribute to this research are able to nominate species to sequence, and download and share data to i5k website.

[2] Mark D. Sytsma; Jeffery R. Cordell; John W. Chapman; Robyn C. Draheim (October 2004).

Pennak's freshwater invertebrates of the United States: Porifera to Crustacea (4th ed.).

Productivity of World Ecosystems: Proceedings of a Symposium Presented August 31–September 1, 1972, at the V General Assembly of the Special Committee for the International Biological Program, Seattle, Washington.

https://doi.org/10.1021/acs.est.8b00837 [9] Nebeker, A; Miller, C. "Use of the amphipod crustacean Hyalella azteca in freshwater and estuarine sediment toxicity tests".

Testing the bioaccumulation potential of manufactured nanomaterials in the freshwater amphipod Hyalella azteca.

Fitness costs of pesticide resistance in Hyalella azteca under future climate change scenarios.

The amphipod Hyalella azteca as a biomonitor in field deployment studies for metal mining.

https://doi.org/10.1016/j.envpol.2008.03.001 [13] Yihao Duan; Sheldon I. Guttman; James T. Oris; A. John Bailer (2000).

"Genetic structure and relationships among populations of Hyalella azteca and H. montezuma (Crustacea:Amphipoda)".

"Redescription of Hyalella azteca from its type locality, Vera Cruz, Mexico (Amphipoda: Hyalellidae)".

Prediction of a peptidome for the ecotoxicological model Hyalella azteca( Creustacea; Amphipoda) using a de novo assembled transcriptome.

Pairing Behavior and reproduction in Hyalella azteca as sensitive endpoints for detecting long-term consequences of pesticide pulses.