There are 1,774 species of crustaceans recorded in Ireland.^{[1][2][3][4][5][6][7][8][9]}

Crustaceans are arthropods of the subphylum Crustacea. Most are aquatic, such as shrimp, barnacles, lobsters, crayfish, krill, but some are also adapted for land living, such as woodlice and crabs.

• Bosmina

41 species including

• Kurzia latissima

Eurycercus lamellatus

Eurycercus glacialis

• Ilyocryptus sordidus

12 species including

• Ceriodaphnia quadrangula
• Daphnia longispina
• Daphnia pulex
• Simocephalus vetulus

8 species

3 species

• Sida crystallina
• Latona setifera

1 species

1 species

1 species

• Polyphemus pediculus

2 species

4 species

2 species including

• Nebalia bipes

1 species

1 species

15 species including

• Aora gracilis
• Lembos websteri
• Microdeutopus anomalus

15 species including

• Ampelisca aequicornis
• Ampelisca brevicornis
• Ampelisca diadema
• Ampelisca spinipes
• Ampelisca tenuicornis
• Ampelisca typica

6 species including

• Amphitholina cuniculus
• Ampithoe gammaroides
• Ampithoe helleri
• Ampithoe rubricata
• Sunamphitoe pelagica

• Calliopius laeviusculus

11 species including

• Caprella acanthifera
• Caprella equilibra
• Caprella linearis
• Caprella mutica (Japanese skeleton shrimp)
• Phtisica marina
• Pariambus typicus

1 species

• Cheirocratus sundevalli

14 species including

• Chelicorophium chelicorne
• Corophium arenarium
• Corophium crassicorne
• Corophium curvispinum
• Corophium volutator
• Ericthonius punctatus

1 species

• Crangonyx pseudogracilis

6 species

1 species

8 species including

• Dexamine spinosa

• Eulimnogammarus obtusatus

15–16 species

• Echinogammarus marinus
• Echinogammarus pirloti
• Echinogammarus stoerensis
• Gammarus duebeni
• Gammarus finmarchicus
• Gammarus lacustris
• Gammarus locusta
• Gammarus pulex
• Gammarus tigrinus
• Gammarus zaddachi

2 species

1 species

• Megaluropus agilis

6 species

• Arcitalitrus dorrieni
• Orchestia gammarellus
• Orchestia mediterranea
• Pseudorchestoidea brito
• Talitrus saltator
• Talorchestia deshayesii

2 species

1 species

• Haustorius arenarius

7 species including

• Hyperia galba

6 species

• Hyale pontica
• Hyale prevostii
• Hyale stebbingi

14 species including

• Ischyrocerus anguipes
• Jassa falcata (scud)
• Parajassa pelagica
• Siphonoecetes kroyeranus

4 species

• Leucothoe lilljeborgi

1 species

1 species

10 species including

• Stenothoe marina

42 species including

• Lysianassa ceratina
• Orchomenella nana

2 species

1 species

6 species

1 species

1 species

1 species

3 species

1 species

13 species including

• Melita palmata
• Abludomelita obtusata
• Maerella tenuimana

3 species

• Microniphargus leruthi
• Niphargus kochianus subsp. irlandicus
• Niphargus wexfordensis

11 species including

• Perioculodes longimanus
• Pontocrates altamarinus
• Pontocrates arenarius
• Monocorophium acherusicum
• Synchelidium maculatum

5 species

5–6 species including

• Amphilochus neapolitanus

1 species

8–9 species

• Harpinia antennaria

8 species including

• Gammaropsis nitida
• Gammaropsis maculata

7 species

• Ampelisca aequicornis
• Bathyporeia elegans
• Bathyporeia guilliamsoniana
• Bathyporeia nana
• Bathyporeia pelagica
• Bathyporeia pilosa
• Bathyporeia tenuipes

3 species

• Urothoe brevicornis
• Urothoe elegans
• Urothoe marina
• Urothoe poseidonis

2 species including

• Microprotopus maculatus

1 species

1 species

2 species

3 species

2 species

2? species

10 species

5 species

4 species

4 species

1 species

1 species

3 species

1species

1 species

1 species

1 species

1 species

• Antrobathynella stammeri

9 species including

• Bodotria scorpioides
• Cumopsis fagei
• Cumopsis goodsiri
• Vaunthompsonia cristata

12 species including

• Diastylis rugosa
• Diastylis bradyi
• Diastylis laevis
• Diastylis rathkei

2 species

6 species

2 species

• Pseudocuma longicorne
• Pseudocuma simile

2 species

1 species

13 species

1 species

2 species

1 species

3 species

1 species

4 species

9 species

1 species

2 species

6 species

2 species

2 species

3 species

1 species

1 species

1 species

1 species

8 species

• Akanthophoreus gracilis

3 species including

• Alpheus macrocheles

1 species

• Austropotamobius pallipes (white-clawed crayfish, Atlantic stream crayfish)

1 species

• Atelecyclus rotundatus (circular crab, round crab, old man's face crab)

1 species

2 species including

• Calocaris macandreae

2 species including

• Callianassa subterranea (mud shrimp, ghost shrimp)

• Apherusa jurinei

2 species including

• Cancer pagurus (edible crab, brown crab)

1 species

• Corystes cassivelaunus (masked crab, helmet crab, sand crab)

11 species including

• Crangon allmanni
• Crangon crangon (brown shrimp, common shrimp, bay shrimp, sand shrimp)
• Pontophilus spinosus

1 species

• Diogenes pugilator (small hermit crab, south-claw hermit crab)

• Pisa tetraodon

10 species including

• Galathea intermedia
• Galathea nexa
• Galathea squamifera (black squat lobster, Montagu's plated lobster)
• Galathea strigosa
• Munida rugosa (rugose squat lobster, plated lobster)

1 species

• Goneplax rhomboides (angular crab)

2 species including

• Eriocheir sinensis (Chinese mitten crab, Shanghai hairy crab)

13 species including

• Hippolyte varians
• Thoralus cranchii

• Inachus dorsettensis (scorpion spider crab)
• Inachus leptochirus
• Inachus phalangium (Leach's spider crab)
• Macropodia rostrata (common spider crab, long-legged spider crab, long-legged crab)
• Macropodia tenuirostris (slender spider crab)

5 species including

• Ebalia tuberosa (Pennant's nut crab)
• Ebalia tumefacta (Bryer's nut crab)

17 species including

• Eurynome aspera
• Eurynome spinosa
• Maja brachydactyla
• Maja squinado (European spider crab, spiny spider crab, spinous spider crab)

• Homarus gammarus (European/common lobster)

3 species including

• Nephrops norvegicus (Norway lobster, Dublin Bay prawn, langoustine, scampi)

11 species including

• Anapagurus chiroacanthus
• Anapagurus hyndmanni
• Anapagurus laevis
• Cestopagurus timidus
• Pagurus bernhardus (common hermit crab, soldier crab)
• Pagurus cuanensis
• Pagurus prideaux
• Pagurus pubescens

1 species

• Hyas araneus (great spider crab)
• Hyas coarctatus

• Palaemon elegans
• Palaemon serratus (common prawn)
• Palaemonetes varians (common ditch shrimp, river shrimp, Atlantic ditch shrimp)

2 species including

• Palinurus elephas (European spiny lobster, crayfish, cray, common spiny lobster, Mediterranean lobster, red lobster)

5 species including

• Pandalus montagui (pink shrimp, Aesop shrimp, Aesop prawn)

• Pilumnus hirtellus (bristly crab, hairy crab)

2 species including

• Pinnotheres pisum (pea crab)

1 species

• Pirimela denticulata

2 species

• Pisidia longicornis (long-clawed porcelain crab)
• Porcellana platycheles (broad-clawed porcelain crab)

14 species including

• Carcinus maenas (European green crab, European shore crab)
• Liocarcinus corrugatus (wrinkled swimming crab)
• Liocarcinus depurator (harbour crab, sandy swimming crab)
• Liocarcinus holsatus (flying crab)
• Liocarcinus marmoreus (marbled swimming crab)
• Liocarcinus navigator (arch-fronted swimming crab)
• Liocarcinus pusillus (dwarf swimming crab)
• Necora puber (velvet crab)
• Portumnus latipes (pennant's swimming crab)

3 species

• Eualus occultus
• Eualus pusiolus

2 species

• Upogebia deltaura
• Upogebia stellata

6 species including

• Xantho hydrophilus
• Xantho pilipes

• Cyathura carinata

3 species

• Astacilla longicornis

7 species

• Armadillidium album
• Armadillidium vulgare (pill-bug, pill woodlouse, roly-poly, doodle bug, potato bug, carpenter)

• Asellus aquaticus (waterlouse, aquatic sowbug, water hoglouse)
• Proasellus meridianus (one-spotted waterlouse, one-spotted water-slater)

• Nototropis swammerdamei
• Nototropis falcatus

10 species

• Eurydice pulchra (speckled sea louse)
• Eurydice affinis

8 species

• Idotea baltica
• Idotea chelipes
• Idotea granulosa
• Idotea linearis
• Idotea neglecta
• Idotea pelagica

10 species

• Ianiropsis breviremis
• Jaera albifrons
• Jaera forsmani
• Jaera nordmanni
• Janira maculosa

1 species

• Ligia oceanica (sea slater, common sea slater, sea roach)

2 species

• Limnoria lignorum (gribble)

4 species

• Munna kroyeri

1 species

• Oniscus asellus (common woodlouse)

1 species

• Philoscia muscorum (common striped woodlouse, fast woodlouse)

8 species

• Porcellio scaber (common rough woodlouse)
• Porcellionides pruinosus

• Dynamene bidentata
• Lekanesphaera hookeri
• Lekanesphaera rugicauda (Sphaeroma rugicauda)
• Sphaeroma serratum

13 species

• Androniscus dentiger (rosy / pink woodlouse)
• Trichoniscus pusillus (common pygmy woodlouse)

2 species

2 species

1 species

2 species

6 species

2 species

2 species

7 species

1 species

3 species

1 species

1 species

1 species

1 species

1 species

1 species

6 species

2 species

10 species

1 species

3 species

66 species including

• Gastrosaccus spinifer
• Hemimysis anomala (bloody-red mysid)
• Leptomysis gracilis
• Leptomysis lingvura
• Mysis relicta
• Neomysis integer
• Praunus flexuosus (chameleon shrimp)

• Pseudoparatanais batei (incerta sedis)

1 species

• Tanais dulongii

2 species

3 species

2 species

1species

2 species

1 species

2 species

2 species including

• Argulus foliaceus (common fish louse)

1 species

5 species including

• Calocalanus contractus

6 species including

• Diaptomus castor

4 species

10 species

6 species

8 species

12 species

28 species

6 species

2 species

2 species

6 species

4 species

1 species

1 species

4 species

5 species

7 species

1 species

4 species

3 species

3 species

7 species

35 species

12 species

12 species

22 species

2 species

3 species

3 species

1 species

1 species

• Sacculina carcini

2 species

• Mychophilus roseus

6 species

8 species

6 species

8 species

41 species

23 species

12 species

3 species

• Cylindropsyllus laevis

• Diarthrodes roscoffensis

12 species

• Tigriopus brevicornis (tigger-pod)

6 species

2 species

2 species

16-17 species

2 species

1 species

5 species

1 species

18 species

4-5 species

8 species

2 species

4 species

34 species

1 species

1 species

1 species

38 species

1 species

23 species

5 species

6 species

26 species

1 species

2 species

8 species

1 species

3 species

2 species

36 species

1 species

2 species

3 species

2 species

3 species

4 species

1 species

4 species

16-17 species

5 species

14 species

2 species

3 species

1 species

3 species

1 species

1 species

2-3 species

2 species

2 species

6 species

3 species

1 species

2 species

1 species

1 species

1 species

1 species

16 species

1 species

5 species

1 species

1 species

2 species

8 species

1 species

18 species including

• Lepeophtheirus pectoralis

1 species

3 species

3 species

1species

1 species

1 species

6 species

2 species

10-11 species

7 species

6 species

• Lepas anatifera (pelagic gooseneck barnacle, smooth gooseneck barnacle)
• Dosima fascicularis

4 species including

• Scalpellum scalpellum

2 species

1 species

3 species including

• Semibalanus balanoides

6-7 species including

• Balanus balanus
• Balanus crenatus
• Balanus perforatus
• Elminius modestus

2 species

• Chthamalus montagui (Montagu's stellate barnacle)
• Chthamalus stellatus (Poli's stellate barnacle)

1 species

• Megatrema anglicum (Boscia anglica)

1 species

• Verruca stroemia

1 species

1species

2 species

1species

2 species

2-3 species

1species

4 species

1 species

1 species

13 species

5 species

4 species

5 species

8 species

1 species

11 species

6 species

2 species

2 species

22 species including

• Candona candida

25 species including

• Cypris

2 species

3 species

• Crabs of the British Isles

• P. J. Hayward and J. S. Ryland Eds., 1999 The Marine Fauna of the British Isles and North-West Europe: Volume II: Molluscs to Chordates Oxford University Press ISBN 9780198575153
• Howson, C.M. & Picton, B.E.(eds) 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas.Ulster Museum and The Marine Conservation Society, Belfast and Ross-on-Wye.
• Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels, 50: pp. 180–213
• Ferriss, S. E.; Smith, K. G.; Inskipp, T. P., eds. (2009). "Irish Biodiversity: a taxonomic inventory of fauna" (PDF). National Parks & Wildlife Service.
• Roche, C.; Clarke, S.; O’Connor, B. (2005). "Inventory of Irish marine wildlife publications, Irish Wildlife Manuals, No. 16" (PDF). National Parks and Wildlife Service, Department of Environment, Heritage and Local Government. Dublin, Ireland.
• Fauna Europaea (land and freshwater) finds 207 species in Ireland for Subphylum Crustacea

• World Register of Marine Species