Palaemonidae

Rafinesque, 1815

palaemonid shrimps

Genus Guides

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Palaemonidae is a large of caridean shrimp comprising over 1,200 in approximately 160 . The family exhibits remarkable ecological diversity, inhabiting marine, estuarine, and freshwater environments worldwide except the deep sea. Two historically recognized —Palaemoninae and Pontoniinae—were merged in 2015 based on molecular and morphological evidence, with former families Gnathophyllidae and Hymenoceridae also incorporated. Members display varied feeding strategies including carnivory, detritivory, and symbiotic associations with . The genus Macrobrachium contains commercially significant species supporting fisheries and aquaculture globally.

Palaemon vulgaris by (c) Smithsonian Environmental Research Center, some rights reserved (CC BY). Used under a CC-BY license.Palaemonidae by (c) Bart, some rights reserved (CC BY), uploaded by Bart. Used under a CC-BY license.Palaemon paludosus (I2054) 0780 (44226581775) by Smithsonian Environmental Research Center. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Palaemonidae: /ˌpæl.iːˈmɒnɪˌdiː/

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Images

Habitat

Marine, estuarine, and freshwater (limnic) environments. Absent from deep sea. Freshwater has occurred repeatedly from marine ancestors, with some completing entire in freshwater while others require saltwater for larval development.

Distribution

Worldwide distribution across tropical and temperate regions. Present in Atlantic, Pacific, and Indian Ocean drainages. Specific distribution records from Denmark, Norway, and Sweden in GBIF database.

Diet

Variable across the : carnivory on small (documented in Palaemoninae), detritivory (common in Pontoniinae), and specialized feeding modes including cleaning and on invertebrates.

Host Associations

  • sponges - commensalism or cleaning Pontoniinae associate with sponges as cleaner shrimps or commensals
  • cnidarians - commensalism or cleaning Pontoniinae associate with cnidarians as cleaner shrimps or commensals
  • mollusks - commensalism or cleaning Pontoniinae associate with mollusks as cleaner shrimps or commensals
  • echinoderms - commensalism or cleaning Former Gnathophyllidae members and Pontoniinae associate with echinoderms; includes parasitic, commensal, and cleaning relationships
  • ascidians (tunicates) - endosymbiosisSome live inside tunicate cavities, with fully adapted small smooth bodies
  • gorgonians - commensalismPericlimenes associate with plexaurid gorgonians such as Muricea and Plexaurella
  • burrowing animals - inquilinismFew recorded living in burrows constructed by other animals, including stomatopods, echiurans, and ghost/mud shrimps; much less diverse than Alpheidae in this regard

Life Cycle

Complex strategies including: (1) complete freshwater cycles with hyper- from hatching (e.g., Macrobrachium pantanalense); (2) diadromous patterns with freshwater exporting larvae to estuaries requiring saltwater for development (e.g., Macrobrachium amazonicum, Cryphiops caementarius); (3) upstream driven by metabolic responses to temperature changes. Eleven distinct larval stages documented in some . Recruitment periods vary seasonally; in Macrobrachium acanthurus, recruitment extends October to May with reproductive peak April–September.

Behavior

upstream in riverine triggered by metabolic responses to acute temperature changes. Thermal sensitivity (Q10) varies with salinity, showing defined patterns in brackish waters below 20‰. Some species exhibit specialized burrow-association, though less diverse than in Alpheidae.

Ecological Role

Cleaner shrimp services on coral reefs; nutrient cycling through detritivory; prey for higher in freshwater and marine .

Human Relevance

Commercially fished in Macrobrachium support artisanal fisheries (e.g., M. acanthurus in Brazil, M. amazonicum in Amazon basin). Aquaculture of Macrobrachium rosenbergii introduced to Mexico (1973) and cultivated in China, India, Thailand. High larval mortality in culture (89–90%) due to infectious and protozoan via food sources.

Similar Taxa

  • AlpheidaeBoth contain symbiotic shrimp with associations, but Alpheidae exhibit far greater diversity of burrow-dwelling and possess distinctive snapping claws absent in Palaemonidae
  • AtyidaeBoth contain freshwater caridean shrimp, but Atyidae lack the complex larval export strategies and osmoregulatory adaptations to salinity variation seen in many Palaemonidae

Sources and further reading