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Anfipodi

Amphipods are a whole order of crustaceans without a carapace, with about 11,000 species divided into six suborders. 1 2 3 They are common above all on the bottom and carry energy from primary producers up to the higher levels of food webs. 7 Their diet varies a great deal between species. 5

Anfipodi

At a glance

Data from the scientific sources listed at the bottom.

Conservation

NEDDLCNTVUENCREWEX

IUCN Red List: not evaluated.

Where it lives

They are found all over the world, in the sea, in fresh water and even on land. 3

How to recognise it

Tap a number on the photo: the key explains what to look for.

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  1. 1Body compressed sideways without a carapace, the typical shape of gammarids 3 4
  2. 2Thoracic legs usually seven pairs, different from one another 3 4
  3. 3Uropods rear appendages, two to three pairs 3
  4. 4Antennae the first has a distinct peduncle and flagellum 3

Life in the wild

Where it is found

They live in marine, brackish and freshwater environments, on the bottom or in the water column, often tied to solid substrates along coasts. 7 Some species form very dense colonies, with more than 100,000 individuals per square metre, hidden among debris and plant remains. 6

What it eats

In a study of 149 Iberian species the main food was detritus, but some species were carnivorous and others ate algae; assigning a single diet to a whole family is not always correct. 5 The group also includes omnivores, scavengers and parasites. 7

Behaviour

The body is usually compressed from side to side, but in burrowing or tube-dwelling forms it is flattened from top to bottom. 4 Among gammarids the first two pairs of legs are often pincer-like. 4 High cannibalism has been seen in the laboratory, especially by males. 6

Reproduction

The female keeps the eggs in a brood pouch under the thorax and the young hatch there, with no free-living larva. 3 4 6 In Parhyale hawaiensis maturity is reached in about 51 days, with about 13 embryos per female. 6

In the aquarium

From the experience of the BallingMania community.

Community rating

No rating in the original sheet.

Original sheet

They are small crustaceans that scurry over the rocks and the sand; essentially they are scavengers that feed on phytoplankton and detritus.

Having them in the tank is a good sign: it shows that the whole aquarium system is in excellent health. They are a food source for everything that feeds on small crustaceans (including Synchiropus fish and wrasses).

In a well-established refugium they breed prolifically. They are easy to recognise because they are shaped like a tiny shrimp.

good or bad?

VERDICT:

Key: Good! An organism beneficial to the system. Reef Safe!

An organism whose benign or harmful nature is not yet known, to be kept an eye on.

Bad! The organism is a threat to the other inhabitants of the aquarium or could become a pest.

A food source for the other inhabitants of the aquarium.

A potentially toxic or venomous organism.

© Michael Marmach · © Marc Levenson

What studies say about keeping it

In aquaculture studies amphipods are proposed as live food alternative to Artemia, for example for seahorses, because they are rich in the fatty acids EPA and DHA. 6 7 Parhyale hawaiensis bred easily in the laboratory, but Elasmopus pectenicrus did not: there are still no established rearing techniques. 6

Did you know?

The mandarinfish, Synchiropus splendidus, feeds on small crustaceans on the bottom, including amphipods. 8
The species Grandidierella halophila has been found in the hypersaline waters of Thai salt pans. 7

Sources

  1. Horton T., Lowry J., De Broyer C. et al. (eds.) (2026). Amphipoda Latreille, 1816. World Register of Marine Species.
  2. Horton T., Lowry J., De Broyer C. et al. (2026). World Amphipoda Database. WoRMS.
  3. Lowry J.K. (1999). Crustacea, the Higher Taxa: Amphipoda. Australian Museum.
  4. Lincoln 1979 and McLaughlin 1980, via Naturalis (2026). Zooplankton and Micronekton of the North Sea 2.0: Subordo Gammaridea. Naturalis Biodiversity Center.
  5. Guerra-García J.M., Tierno de Figueroa J.M., Navarro-Barranco C., Ros M., Sánchez-Moyano J.E., Moreira J. (2014). Dietary analysis of the marine Amphipoda (Crustacea: Peracarida) from the Iberian Peninsula. Journal of Sea Research 85.
  6. Vargas-Abúndez J.A., López-Vázquez H.I., Mascaró M., Martínez-Moreno G.L., Simões N. (2021). Marine amphipods as a new live prey for ornamental aquaculture: exploring the potential of Parhyale hawaiensis and Elasmopus pectenicrus. PeerJ 9:e10840.
  7. Suhaimi H., Abdul Rahman M.I., Ashaari A., Ikhwanuddin M., Wan Rasdi N. (2024). Adaptation and potential culture of wild Amphipods and Mysids as potential live feed in aquaculture: a review. PeerJ 12:e17092.
  8. Patel K. (2006). Synchiropus splendidus, Mandarin-fish. Animal Diversity Web, University of Michigan.

Sources checked on 5 November 2026. Community texts and ratings are kept separate from the scientific data.

Download the original sheet (Italian)All species