Haliotis, common name abalone, is the only genus in the family Haliotidae.[2]

Haliotis
Temporal range: Late Cretaceous – Recent[1]
Living abalone in tank showing epipodium and tentacles, anterior end to the right.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Vetigastropoda
Order: Lepetellida
Superfamily: Haliotoidea
Family: Haliotidae
Rafinesque, 1815
Genus: Haliotis
Linnaeus, 1758
Type species
Haliotis asinina
Synonyms[2]
  • Euhaliotis Wenz, 1938
  • Eurotis Habe & Kosuge, 1964
  • Exohaliotis Cotton & Godfrey, 1933
  • Haliotis (Haliotis) Linnaeus, 1758
  • Haliotis (Marinauris) Iredale, 1937
  • Haliotis (Nordotis) Habe & Kosuge, 1964
  • Haliotis (Notohaliotis) Cotton & Godfrey, 1933
  • Haliotis (Padollus) Montfort, 1810
  • Haliotis (Paua) C. Fleming, 1953
  • Haliotis (Sulculus) H. Adams & A. Adams, 1854
  • Marinauris Iredale, 1927
  • Neohaliotis Cotton & Godfrey, 1933
  • Nordotis Habe & Kosuge, 1964
  • Notohaliotis Cotton & Godfrey, 1933
  • Ovinotis Cotton, 1943
  • Padollus Montfort, 1810
  • Paua C. Fleming, 1953
  • Sanhaliotis Iredale, 1929
  • Schismotis Gray, 1856
  • Teinotis H. Adams & A. Adams, 1854
  • Tinotis P. Fischer, 1885 (invalid: unjustified emendation of Teinotis)
  • Usahaliotis Habe & Kosuge, 1964

This genus once contained six subgenera. These subgenera have become alternate representations of Haliotis.[2] The genus consists of small to very large, edible, herbivorous sea snails, marine gastropod molluscs. The number of species recognized worldwide ranges between 30[3] and 130,[4] with over 230 species-level taxa described. The most comprehensive treatment of the family considers 56 species valid, with 18 additional subspecies.[5]

Other common names are ear shells, sea ears, and, rarely, muttonfish or muttonshells in parts of Australia, ormer in the UK, perlemoen in South Africa, and the Māori name for three species in New Zealand is pāua.[6]

Description

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The iridescent inside surface of a red abalone shell from Northern California: The coin is about one inch in diameter.

The shells of abalones have a low, open, spiral structure, and are characterized by having several open respiratory pores in a row near the shell's outer edge. The thick inner layer of the shell is composed of nacre, which in many species of abalone is highly iridescent, giving rise to a range of strong, changeable colors, which make the shells attractive to humans as decorative objects, in jewelry, and as a source of colorful mother-of-pearl.

The shell of abalones is convex, rounded to oval shape, and may be highly arched or very flattened. The shell of the majority of species is ear-shaped, presenting a small, flat spire and two to three whorls. The last whorl, known as the body whorl, is auriform, meaning that the shell resembles an ear, giving rise to the common name "ear shell". Haliotis asinina has a somewhat different shape, as it is more elongated and distended. The shell of Haliotis cracherodii cracherodii is also unusual as it has an ovate form, is imperforate, shows an exserted spire, and has prickly ribs.

A mantle cleft in the shell impresses a groove in the shell, in which are the row of holes (known as tremata), characteristic of the genus. These holes are respiratory apertures for venting water from the gills and for releasing sperm and eggs into the water column. They make up what is known as the selenizone which forms as the shell grows. This series of eight to 38 holes is near the anterior margin. Only a small number are generally open. The older holes are gradually sealed up as the shell grows and new holes form. Therefore, the number of tremata is not characteristic for the species. Each species has a number of open holes, between four and 10, in the selenizone. This number is not fixed and can vary within a species and between populations. Abalones have no operculum. The aperture of the shell is very wide and nacreous.

The exterior of the shell is striated and dull. The color of the shell is very variable from species to species, which may reflect the animal's diet.[6] The iridescent nacre that lines the inside of the shell varies in color from silvery white, to pink, red and green-red, to deep blue, green to purple.

The animal shows fimbriated head-lobes. The side-lobes are also fimbriated and cirrated. The rounded foot is very large. The radula has small median teeth, and the lateral teeth are single and beam-like. About 70 uncini are present, with denticulated hooks, the first four very large. The soft body is coiled around the columellar muscle, and its insertion, instead of being on the columella, is on the middle of the inner wall of the shell. The gills are symmetrical and both well developed.[7]

These snails cling solidly with their broad muscular foot to rocky surfaces at sublittoral depths, although some species such as Haliotis cracherodii used to be common in the intertidal zone. Abalones reach maturity at a relatively small size. Their fecundity is high and increases with their size (from 10,000 to 11 million eggs at a time). The spermatozoa are filiform and pointed at one end, and the anterior end is a rounded head.[8]

The larvae are lecithotrophic. The adults are herbivorous and feed with their rhipidoglossan radula on macroalgae, preferring red or brown algae. Sizes vary from 20 mm (0.79 in) (Haliotis pulcherrima) to 200 mm (7.9 in), while Haliotis rufescens is the largest of the genus at 12 in (30 cm).[9]

By weight, about one-third of the animal is edible meat, one-third is offal, and one-third is shell.[citation needed]

Structure and properties of the shell

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The shell of the abalone is exceptionally strong and is made of microscopic calcium carbonate tiles stacked like bricks. Between the layers of tiles is a clingy protein substance. When the abalone shell is struck, the tiles slide instead of shattering and the protein stretches to absorb the energy of the blow. Material scientists around the world are studying this tiled structure for insight into stronger ceramic products such as body armor.[10] The dust created by grinding and cutting abalone shell is dangerous; appropriate safeguards must be taken to protect people from inhaling these particles. There is much discussion of this topic online.[citation needed][11][12]

Species

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The number of species that are recognized within the genus Haliotis has fluctuated over time, and depends on the source that is consulted. The number of recognized species ranges from 30[3] to 130.[4] This list finds a compromise using the "WoRMS" database, plus some species that have been added, for a total of 57.[2][13] The majority of abalone have not been evaluated for conservation status. Those that have been reviewed tend to show that the abalone in general is declining in numbers, and will need protection throughout the globe.

Extant species

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Species of abalone
Species Range Conservation status
Haliotis alfredensis Bartsch, 1915[nb 1] South Africa DD IUCN
Haliotis arabiensis Owen, Regter & Van Laethem, 2016 Off Yemen and Oman NT IUCN
Haliotis asinina Linnaeus, 1758 Philippines; Indonesia; Australia; Japan; Thailand; Vietnam LC IUCN
Haliotis australis Gmelin, 1791 New Zealand LC IUCN
Haliotis brazieri Angas, 1869 Eastern Australia NT IUCN
Haliotis clathrata Reeve, 1846 Seychelles; Comores; Madagascar; Mauritius; Kenya LC IUCN
Haliotis coccoradiata Reeve, 1846 Eastern Australia LC IUCN
Haliotis corrugata Wood, 1828 California, USA; Baja California, Mexico CR IUCN, Species of Concern National Marine Fisheries Service;[16] Vulnerable (global) and imperiled (California) California Department of Fish and Wildlife[17]
Haliotis cracherodii Leach, 1814 California, USA; Baja California, Mexico CR IUCN, Vulnerable (Global, Nation: US, State: California) California Department of Fish and Wildlife;[17][18] Listed endangered National Marine Fisheries Service[19]
Haliotis cyclobates Péron & Lesueur, 1816 Southern Australia LC IUCN
Haliotis dalli Henderson, 1915 Galapagos Islands, western Colombia DD IUCN
Haliotis discus Reeve, 1846 Japan; South Korea EN IUCN
Haliotis dissona (Iredale, 1929) Australia; New Caledonia LC IUCN
Haliotis diversicolor Reeve, 1846 Japan; Australia; Southeast Asia DD IUCN
Haliotis drogini Owen & Reitz, 2012 Cocos Island VU IUCN
Haliotis elegans Koch & Philippi, 1844 Western Australia LC IUCN
Haliotis exigua Dunker, R.W., 1877 (synonym of H. diversicolor) Japan Not evaluated
Haliotis fatui Geiger, 1999 Tonga Mariana Islands DD IUCN
Haliotis fulgens Philippi, 1845 California, USA; Baja California, Mexico CR IUCN, Vulnerable (Global, State: California California Department of Fish and Wildlife);[17] Species of Concern NMFS[20]
Haliotis geigeri Owen, 2014 São Tomé and Príncipe Islands VU IUCN
Haliotis gigantea Gmelin, 1791 Japan EN IUCN
Haliotis glabra Gmelin, 1791 Philippines; Vietnam LC IUCN
Haliotis iris Gmelin, 1791 New Zealand LC IUCN
Haliotis jacnensis Reeve, 1846 Japan; Nicobar Islands; Ryukyu Islands; Pacific Islands; LC IUCN
Haliotis kamtschatkana Jonas, 1845 Western North America EN IUCN, Imperiled (Alaska, British Columbia), Vulnerable (global, US), critically imperiled (California);[17][21] Species of Concern NMFS[22]
Haliotis laevigata Donovan, 1808 South Australia; Tasmania VU IUCN
Haliotis madaka (Habe, 1977) Japan; South Korea EN IUCN
Haliotis mariae Wood, 1828 Oman; Yemen EN IUCN
Haliotis marmorata Linnaeus, 1758 Liberia; Ivory Coast; Ghana LC IUCN
Haliotis melculus (Iredale, 1927) Australia (New South Wales, Queensland) VU IUCN
Haliotis midae Linnaeus, 1758 South Africa EN IUCN
Haliotis mykonosensis Owen, Hanavan & Hall, 2001 Greece; Turkey; Tunisia LC IUCN
Haliotis ovina Gmelin, 1791 Thailand; Vietnam; southern part of the Pacific Ocean; Andaman Islands; Maldives; Ryukyu Islands LC IUCN
Haliotis papulata Reeve, 1846 Australia; Papua New Guinea; Philippines; Sri Lanka; Thailand LC IUCN
Haliotis parva Linnaeus, 1758 South Africa; Angola DD IUCN
Haliotis planata G. B. Sowerby II, 1882 Ryukyu Islands; Sri Lanka; Indonesia; Fiji; Andaman Sea LC IUCN
Haliotis pourtalesii Dall, 1881 Eastern USA; Gulf of Mexico; Eastern South America; northern Colombia DD IUCN
Haliotis pulcherrima Gmelin, 1791 Polynesia DD IUCN
Haliotis queketti E.A. Smith, 1910 Eastern Africa DD IUCN
Haliotis roei Gray, 1826 Australia NT IUCN
Haliotis rubiginosa Reeve, 1846 Lord Howe Island CR IUCN
Haliotis rubra Leach, 1814 Southern and Eastern Australia VU IUCN
Haliotis rufescens Swainson, 1822 Western North America CR IUCN, apparently secure (global, US); critically imperiled (Canada)[23]
Haliotis rugosa Lamarck, 1822 South Africa; Madagascar; Mauritius; Red Sea LC IUCN
Haliotis scalaris (Leach, 1814) Southern and Western Australia LC IUCN
Haliotis semiplicata Menke, 1843 Western Australia LC IUCN
Haliotis sorenseni Bartsch, 1940 California, USA; Baja California, Mexico CR IUCN, critically imperiled (global, US, California);[17][24] Endangered NMFS[25]
Haliotis spadicea Donovan, 1808 South Africa LC IUCN
Haliotis speciosa Reeve, 1846 (synonym of H. tuberculata) Eastern South Africa Not evaluated
Haliotis squamosa Gray, 1826 Southern Madagascar DD IUCN
Haliotis stomatiaeformis Reeve, 1846 Malta; Sicily VU IUCN
Haliotis supertexta Lischke, 1870 (synonym of H. diversicolor) Japan; Sao Tome Not evaluated
Haliotis thailandis Dekker & Patamakanthin, 2001 (synonym of H. papulata) Andaman Sea Not evaluated
Haliotis tuberculata Linnaeus, 1758 Ireland (introduced); Channel Islands; Azores; Canary Islands; Madeira ; Brittany; Great Britain VU IUCN
Haliotis unilateralis Lamarck, 1822 Gulf of Aqaba; East Africa; Seychelles; LC IUCN
Haliotis varia Linnaeus, 1758 Mascarene Basin; Red Sea; Sri Lanka; Western Pacific; LC IUCN
Haliotis virginea Gmelin, 1791 New Zealand; Chatham Islands; Auckland Islands; Campbell Island LC IUCN
Haliotis walallensis Stearns, 1899 Western North America CR IUCN

Fossil species

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Conservation

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Over half of the modern Haliotis species with sufficient data are considered threatened to some extent on the IUCN Red List, with all but one species from the Pacific coast of North America being critically endangered as a consequence of massive historical overharvesting, withering abalone syndrome, and recent marine heatwaves which have caused collapses of both abalones and their habitat. Haliotis species from elsewhere are also threatened by overexploitation and climate change. In addition, abalones as a whole are considered highly vulnerable to ocean acidification due to their accretion of aragonite and dependence on susceptible coralline algae for development, and thus may eventually go extinct unless the rate of ocean acidification is arrested.[26][27][28][29]

Synonyms

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See also

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References

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  1. ^ Geiger & Groves 1999, p. 872
  2. ^ a b c d Gofas, Tran & Bouchet 2014
  3. ^ a b Dauphin et al. 1989, p. 9
  4. ^ a b Cox 1962, p. 8
  5. ^ D.L., Geiger (1999). "Distribution and biogeography of the recent Haliotidae (Gastropoda: Vetigastropoda) world-wide". Bollettino Malacologico.
  6. ^ a b Beesley, Ross & Wells 1998[page needed]
  7. ^ Tryon 1880, p. 41
  8. ^ Tryon 1880, p. 46
  9. ^ Hoiberg 1993, p. 7
  10. ^ Lin & Meyers 2005, p. 27 & 38
  11. ^ Abalone Toxicity https://orchid.ganoksin.com/t/abalone-toxicity/9357/2
  12. ^ Shell Dust Dangers https://www.banjohangout.org/archive/187285
  13. ^ Abbott & Dance 2000
  14. ^ Tran & Bouchet 2009
  15. ^ EoL 2014
  16. ^ Neuman 2007
  17. ^ a b c d e State of California 2011
  18. ^ Anon 2014f
  19. ^ Anon 2009
  20. ^ Neuman 2009
  21. ^ Anon 2014c
  22. ^ Gustafson & Rumsey 2007
  23. ^ Anon 2014d
  24. ^ Anon 2014e
  25. ^ Anon 2001
  26. ^ IUCN (2021-05-21). "Haliotis rufescens: Peters, H., Rogers-Bennett, L. & De Shields, R.M.: The IUCN Red List of Threatened Species 2021: e.T78771583A78772573". doi:10.2305/iucn.uk.2021-3.rlts.t78771583a78772573.en. S2CID 245151062. {{cite journal}}: Cite journal requires |journal= (help)
  27. ^ Kerlin, Katherine E. (2022-12-12). "All West Coast Abalones at Risk of Extinction on the IUCN Red List". UC Davis. Retrieved 2022-12-24.
  28. ^ "First-ever global Red List assessment of abalone underlines urgency of combatting illegal trade - Wildlife Trade News from TRAFFIC". www.traffic.org. Retrieved 2022-12-24.
  29. ^ Byrne, Maria; Ho, Melanie; Wong, Eunice; Soars, Natalie A.; Selvakumaraswamy, Paulina; Shepard-Brennand, Hannah; Dworjanyn, Symon A.; Davis, Andrew R. (2010-12-22). "Unshelled abalone and corrupted urchins: development of marine calcifiers in a changing ocean". Proceedings of the Royal Society B: Biological Sciences. 278 (1716): 2376–2383. doi:10.1098/rspb.2010.2404. ISSN 0962-8452. PMC 3119014. PMID 21177689.

Notes

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  1. ^ This species, depending on the source is its own species[14] or is a synonym of Haliotis speciosa.[15]

Sources

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