A living guide to Kauaʻi

Shells, Snails & Other Mollusks of Kauaʻi

Explore the island’s native and introduced species, habitats, watersheds and conservation work. Each record connects its description, images and sources with the interactive Atlas.

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  Hawaiian Mussel

  Brachidontes crebristriatus

  A small Hawaiian endemic mussel forming colonies on wave-washed rock. A 2004 survey documented it at three Kauaʻi harbor and reef stations; that evidence does not establish present-day abundance.

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  Orbita Cockle

  Vasticardium orbita

  A cockle directly recorded from Kauaʻi in the Bishop Museum 2002–2003 nearshore assessment under the older combination Trachycardium orbita. Current taxonomy places it in Vasticardium.

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  Cuming's Mussel

  Septifer cumingii

  Directly recorded on Kauaʻi by Bishop Museum as Septifer bryanae. MolluscaBase/WoRMS now treats that name as a synonym of Septifer cumingii.

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  Baggy Pen Shell

  Streptopinna saccata

  A thin, ruffled pen shell documented at Hoʻai Bay in a November 2002 Kauaʻi reef survey. The complete adult reconstruction shows the wedge-shaped shell in representative sandy reef habitat; current abundance has not been assessed.

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  Violet Spiny Oyster

  Spondylus violacescens

  TR29a appendix and NOAA HCRI reef report both record Spondylus violacescens from Kauaʻi stations/surveys.

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  Rasp Tellin

  Scutarcopagia scobinata

  A tellin directly recorded from Kauaʻi under the older name Tellina scobinata. Current taxonomy uses Scutarcopagia scobinata.

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  Native Hawaiian Oyster

  Dendostrea sandvichensis

  A small attached oyster with irregular ribs and toothed margins, occurring in Hawaiʻi and elsewhere in the Indo-Pacific. Historical surveys documented it at Nawiliwili and Port Allen on Kauaʻi.

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  Plicate Ark

  Acar plicata

  Bishop Museum Technical Report 29a records the taxon at Kauai stations Ka1, Ka2 and Ka4; later observations corroborate persistence. MolluscaBase/WoRMS Aphia 215258 accepts Acar plicata; the report's Barbatia divaricata usage is bridged by

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  Achatinella bellula

  Achatinella bellula

  Cowie (1997) states it was deliberately introduced from Oahu to Makaweli, Kauai, in 1891 or 1892 and survived to 1911, citing BPBM lots 23449-23455. The Bishop Museum catalog treats Achatinella bellula as the named taxon; no current author

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  Achatinella vulpina

  Achatinella vulpina

  Cowie (1997) documents deliberate introductions to Haupu and Kipu, Kauai, live collections through 1948, and shells in 1973. MolluscaBase/WoRMS Aphia 1486196 accepts Achatinella vulpina. Terrestrial; marine depth screen not applicable. E

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  Ocellated Top

  Alcyna ocellata

  Bishop Museum Technical Report 29a records direct presence at Kauai stations Ka2 and Ka4. MolluscaBase/WoRMS Aphia 593740 accepts Alcyna ocellata. Report 29a is a 2002-2003 survey of harbors and nearby coral reefs, within the Atlas nearsh

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  Graceful Awlsnail

  Allopeas gracile

  Cowie (1997) lists Kauai explicitly and states the Kauai record is based on Bishop Museum collections under junior synonyms oparanus and pyrgiscus. The catalog documents both junior-synonym bridges; MolluscaBase/WoRMS Aphia 875198 accepts

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  Amastra anthonii

  Amastra anthonii

  Four Bishop Museum checklist entries for subspecies explicitly report Kauai. MolluscaBase/WoRMS Aphia 1423712 accepts Amastra anthonii; source subspecies are collapsed only at species rank. Terrestrial; marine depth screen not applicable.

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  Amastra cyclostoma

  Amastra cyclostoma

  Bishop Museum checklist entries for the nominate and gregoryi subspecies explicitly report Kauai. MolluscaBase/WoRMS Aphia 1423692 accepts Amastra cyclostoma. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence a

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  Amastra delicata

  Amastra delicata

  Bishop Museum checklist explicitly reports Kauai. MolluscaBase/WoRMS Aphia 1423699 accepts Amastra delicata. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence and accepted identity are supported, without modern

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  Amastra juddii

  Amastra juddii

  Bishop Museum checklist explicitly reports Kauai. MolluscaBase/WoRMS Aphia 1423697 accepts Amastra juddii. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence and accepted identity are supported, without modern p

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  Amastra kauaiensis

  Amastra kauaiensis

  Bishop Museum checklist explicitly reports Kauai. MolluscaBase/WoRMS Aphia 1451359 accepts Amastra kauaiensis. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence and accepted identity are supported, without mode

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  Amastra knudsenii

  Amastra knudsenii

  Bishop Museum checklist explicitly reports Kauai. MolluscaBase/WoRMS Aphia 1562856 accepts Amastra knudsenii. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence and accepted identity are supported, without moder

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  Amastra nucleola

  Amastra nucleola

  Bishop Museum checklist explicitly reports Kauai. MolluscaBase/WoRMS Aphia 1459659 accepts Amastra nucleola. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence and accepted identity are supported, without modern

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  Amastra ovatula

  Amastra ovatula

  Bishop Museum checklist explicitly reports Kauai. MolluscaBase/WoRMS Aphia 1423721 accepts Amastra ovatula. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence and accepted identity are supported, without modern

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  Amastra ricei

  Amastra ricei

  Two Bishop Museum checklist entries at subspecies rank explicitly report Kauai. MolluscaBase/WoRMS Aphia 1702522 accepts Amastra ricei; subspecies are collapsed at species rank only. Terrestrial; marine depth screen not applicable. Histo

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  Amastra rugulosa

  Amastra rugulosa

  Five Bishop Museum checklist entries at subspecies rank explicitly report Kauai. MolluscaBase/WoRMS Aphia 1423707 accepts Amastra rugulosa; subspecies are collapsed at species rank only. Terrestrial; marine depth screen not applicable. H

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  Amastra similaris

  Amastra similaris

  Bishop Museum checklist explicitly reports Kauai. MolluscaBase/WoRMS Aphia 1716488 accepts Amastra similaris. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence and accepted identity are supported, without moder

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  Amastra sphaerica

  Amastra sphaerica

  Bishop Museum checklist explicitly reports Kauai. MolluscaBase/WoRMS Aphia 1615885 accepts Amastra sphaerica. Terrestrial; marine depth screen not applicable. Historical Kauai occurrence and accepted identity are supported, without moder

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  Anatoma pseudoequatoria

  Anatoma pseudoequatoria

  Bishop Museum Technical Report 29a records direct presence at Kauai coastal stations. MolluscaBase/WoRMS Aphia 594440 accepts Anatoma pseudoequatoria. Report 29a sampled harbors and nearby coral reefs during 2002-2003, within nearshore sc

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  Antisabia foliacea

  Antisabia foliacea

  Bishop Museum Technical Report 29a records the taxon at Kauai coastal stations; two dated observations corroborate. MolluscaBase/WoRMS Aphia 598655 accepts Antisabia foliacea. The authoritative survey covered harbors and nearby coral reef

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  Apataxia cerithiiformis

  Apataxia cerithiiformis

  Bishop Museum Technical Report 29a records the taxon at Kauai coastal stations; dated observations corroborate. MolluscaBase/WoRMS Aphia 871015 accepts Apataxia cerithiiformis. The survey covered harbors and nearby coral reefs. Bishop Mu

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  Arakawania granulata

  Arakawania granulata

  Bishop Museum Technical Report 29a records the taxon at Kauai coastal stations; dated observations corroborate. MolluscaBase/WoRMS Aphia 1775215 accepts Arakawania granulata. The survey covered harbors and nearby coral reefs. Bishop Muse

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  Atagema echinata

  Atagema echinata

  The expert account cites Kay (1979) for occurrence on Kauai. MolluscaBase/WoRMS Aphia 872604 accepts Atagema echinata. Kay's account is summarized as shallow reef platforms and back-reef habitats on Oahu and Kauai. The expert account exp

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  Hilo Risso

  Bittinella hiloensis

  Bishop Museum Technical Report 29a records direct presence at Kauai coastal stations. MolluscaBase/WoRMS Aphia 887301 accepts Bittinella hiloensis. The 2002-2003 survey sampled harbors and nearby coral reefs. Bishop Museum Technical Repo

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  Impending Horn

  Bittium impendens

  Bishop Museum Technical Report 29a records direct presence at Kauai coastal stations. MolluscaBase/WoRMS Aphia 473076 accepts Bittium impendens. The 2002-2003 survey sampled harbors and nearby coral reefs. Bishop Museum Technical Report

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  Asian trampsnail

  Bradybaena similaris

  Cowie (1997) explicitly lists Kauai among the island occurrences. The catalog treats Helix similaris Rang as the valid-name basis; MolluscaBase/WoRMS Aphia 875284 accepts Bradybaena similaris. Terrestrial; marine depth screen not applicab

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  Divided caecum

  Caecum sepimentum

  Bishop Museum Technical Report 29a records direct presence at Kauai coastal stations; a dated observation corroborates. MolluscaBase/WoRMS Aphia 545358 accepts Caecum sepimentum. The 2002-2003 survey sampled harbors and nearby coral reefs

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  Marbled top shell

  Calliotrochus marmoreus

  Bishop Museum Technical Report 29a records direct presence at Kauai coastal stations. MolluscaBase/WoRMS Aphia 567748 accepts Calliotrochus marmoreus. The 2002-2003 survey sampled harbors and nearby coral reefs. Bishop Museum Technical R

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  Calloarca nuttingi

  Calloarca nuttingi

  Bishop Museum Technical Report 29a records direct presence at Kauai coastal stations. MolluscaBase/WoRMS Aphia 504422 accepts Calloarca nuttingi. The 2002-2003 survey sampled harbors and nearby coral reefs. Bishop Museum Technical Report

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  Catinella explanata

  Catinella explanata

  Bishop Museum Hawaiian Biological Survey species checklist explicitly lists island 'Kauai' for Catinella explanata. MolluscaBase/WoRMS AphiaID 1459884 lists Catinella explanata as accepted and terrestrial. Terrestrial taxon; marine depth

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  Catinella rubida

  Catinella rubida

  Bishop Museum Hawaiian Biological Survey species checklist explicitly lists island 'Kauai' for Catinella rubida. MolluscaBase/WoRMS AphiaID 832102 lists Catinella rubida as accepted and terrestrial. Terrestrial taxon; marine depth filter

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  Black-foot ʻOpihi · ʻOpihi Makaiauli

  Cellana exarata

  Bishop Museum TR29 table records presence at Kauaʻi stations Ka1 and Ka3; iNaturalist RG observations 251416561 (Nawiliwili, 2024-11-06) and 320555552 (Glass Beach, 2025-10-12) are explicitly georeferenced on Kauaʻi Island. WoRMS AphiaID 3

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  Yellow-foot ʻOpihi · ʻOpihi ʻĀlinalina

  Cellana sandwicensis

  Bishop Museum TR29 table marks Kauaʻi station Ka3; iNaturalist RG observations 96337115 (Kīlauea, 2021-09-26) and 201554386 (Kōloa, 2024-03-05) have explicit Kauaʻi Island coordinates. WoRMS AphiaID 571924 lists Cellana sandwicensis as acc

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  Kangaroo Nudibranch

  Ceratosoma tenue

  Sea Slugs of Hawaii explicitly includes Kauai in its distribution; iNaturalist RG observations 44648118 (Kōloa Landing, 2020-04-26) and 178325167 (2022-12-22; 22.0101692,-159.3291802) are on Kauaʻi Island. WoRMS AphiaID 212893 lists Cerato

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  Cerithidium diplax

  Cerithidium diplax

  Bishop Museum TR29 coastal-survey table explicitly marks Cerithidium diplax at Kauaʻi station(s), using the report's Ka station columns. WoRMS AphiaID 397036 lists Cerithidium diplax as accepted. Evidence is from an island-coded shallow c

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  Cerithidium perparvulum

  Cerithidium perparvulum

  Bishop Museum TR29 coastal-survey table explicitly marks Cerithidium perparvulum in the Kauaʻi station columns. WoRMS AphiaID 397037 lists Cerithidium perparvulum as accepted. Evidence is from an island-coded shallow coastal marine survey

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  Cerithium interstriatum

  Cerithium interstriatum

  Bishop Museum TR29 coastal-survey table explicitly marks Cerithium interstriatum in Kauaʻi station columns. WoRMS AphiaID 473101 lists Cerithium interstriatum as accepted. Station evidence comes from the shallow coastal marine survey, sat

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  Chama asperella

  Chama asperella

  Bishop Museum TR29 coastal-survey table explicitly records Chama asperella in Kauaʻi station columns. WoRMS AphiaID 208488 lists Chama asperella as accepted. The record is from a shallow coastal marine survey station, not deep-water or ra

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  False Cup-and-Saucer

  Cheilea equestris

  Bishop Museum TR29 coastal-survey table explicitly marks Cheilea equestris in Kauaʻi station columns. WoRMS AphiaID 212110 lists Cheilea equestris as accepted. The occurrence is tied to a shallow coastal marine survey station, not a gener

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  Spotted Swallowtail Slug

  Chelidonura alisonae

  Sea Slugs of Hawaii explicitly includes Kauai; iNaturalist RG observations 12653416 (2018-05-20) and 47378709 (2020-05-25) are georeferenced on Kauaʻi near Salt Pond/ʻEleʻele. WoRMS AphiaID 559045 lists Chelidonura alisonae as accepted. E

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  Blue Swallowtail Slug

  Chelidonura hirundinina

  Sea Slugs of Hawaii explicitly includes Kauai; iNaturalist RG observations 195283501 (Poʻipū, 2014-05-07) and 7529305 (Kalihiwai, 2017-08-16) are on Kauaʻi Island. WoRMS AphiaID 420528 lists Chelidonura hirundinina as accepted; expert acco

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  Purple-spotted Nudibranch

  Chromodoris aspersa

  Bishop Museum TR29 records Kauaʻi station presence; Sea Slugs of Hawaii explicitly includes Kauai; iNaturalist RG observations 19264964 (Poʻipū, 2018) and 270632977 (Ahukini, 2021) have Kauaʻi coordinates. WoRMS AphiaID 558319 lists Chromo

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  Black-and-white Cone

  Conus ebraeus

  HCRI Final Report records this species at Kauaʻi stations KARA2 and KARA7; iNaturalist records include 35342915 from Lawai reef platform and 98231176 from Poʻipū. WoRMS AphiaID 215436 lists Conus ebraeus as accepted. KARA2 is Beach House

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  Yellow Pacific Cone

  Conus flavidus

  HCRI Final Report records Conus flavidus at Kauaʻi stations KARA2, KARA3, and KARA7; iNaturalist adds Lawai Beach (1999) and Princeville (2007) observations. WoRMS AphiaID 215518 lists Conus flavidus as accepted. HCRI stations are explici

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  Miliaris Cone

  Conus miliaris

  Bishop Museum TR29 coastal-survey table explicitly records Conus miliaris in Kauaʻi station columns. WoRMS AphiaID 215533 lists Conus miliaris as accepted. Direct shallow coastal survey context satisfies marine scope. Accepted species wi

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  Hawaiian Penniform Cone

  Conus purus

  Marine Life Photography labels a Kauaʻi specimen ('form Elisae, Kauai, 29 mm'); iNaturalist RG observations 67820400 (Poʻipū, 2002-12-30) and 320988061 (Baby Beach, 2025-10-14) have explicit island coordinates. WoRMS AphiaID 429445 lists C

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  Few-ribbed Cookeconcha

  Cookeconcha paucicostata

  Bishop Museum freshwater/terrestrial checklist explicitly lists Cookeconcha paucicostata for 'Kauai.' MolluscaBase/WoRMS AphiaID 1264722 lists Cookeconcha paucicostata as accepted and terrestrial. Terrestrial taxon; marine filter does not

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  Ribbed Coral Snail

  Coralliophila costularis

  Bishop Museum TR29 coastal-survey table explicitly records Coralliophila costularis in Kauaʻi station columns. WoRMS AphiaID 208124 lists Coralliophila costularis as accepted. Station-level shallow coastal survey evidence satisfies nearsh

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  Brown Garden Snail

  Cornu aspersum

  Cowie (1997) catalog lists Helix aspersa (= Cornu aspersum) with island code K for Kauaʻi. MolluscaBase/WoRMS AphiaID 820000 lists Cornu aspersum as accepted; inspected catalog uses historical combination Helix aspersa. Terrestrial introd

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  Desirable Nudibranch

  Coryphellina exoptata

  Sea Slugs of Hawaii explicitly includes Kauai; iNaturalist RG observations 334279 (Sheraton Caverns, 2010-03-22) and 44658347 (Poʻipū dive site, 2019-10-06) are island-georeferenced. WoRMS AphiaID 1047492 lists Coryphellina exoptata as acc

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  Frida’s Costasiella

  Costasiella fridae

  Sea Slugs of Hawaii explicitly includes Kauai in the distribution of Costasiella fridae; iNaturalist observation 244845094 is tagged Kauai County but mapped inland and therefore is not used as locality proof by itself. WoRMS AphiaID 163508

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  Leaf Sheep

  Costasiella kuroshimae

  Sea Slugs of Hawaii explicitly includes Kauai; iNaturalist observation 244845095 is tagged Kauai County but mapped inland and is not relied on alone. WoRMS AphiaID 494655 lists Costasiella kuroshimae as accepted; expert account notes possi

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  Bourbon Cyerce

  Cyerce bourbonica

  Sea Slugs of Hawaii explicitly includes Kauai; iNaturalist RG observation 44658123 is dated 2019-11-04 at Kōloa Landing, Kauaʻi. WoRMS AphiaID 599819 lists Cyerce bourbonica as accepted. Expert account gives a <1-6 m (<3-20 ft) shallow be

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  Liliʻuokalani Cyerce

  Cyerce liliuokalaniae

  Sea Slugs of Hawaii explicitly includes Kauai in the distribution of Cyerce liliuokalaniae. WoRMS AphiaID 1814160 lists Cyerce liliuokalaniae as accepted; expert account notes the 2025 DNA-based description and bridges older Hawaiian usage