Haliotis


Haliotis[Endangered species|], common name abalone, paua, or ormer, is the only genus in the family Haliotidae.
This genus once contained six subgenera. These subgenera have become alternate representations of Haliotis. The genus consists of small to very large, edible, herbivorous sea snails, marine gastropod molluscs. The number of species recognized worldwide ranges between 30 and 130, with over 230 species-level taxa described. The most comprehensive treatment of the family considers 56 species valid, with 18 additional subspecies.

Description

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, 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, 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 form, is, shows an spire, and has prickly ribs.
A mantle cleft in the shell impresses a groove in the shell, in which are the row of holes, 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.
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. 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 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 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.
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. The spermatozoa are and pointed at one end, and the anterior end is a rounded head.
The larvae are lecithotrophic. The adults are herbivorous and feed with their rhipidoglossan radula on macroalgae, preferring red or brown algae. Sizes vary from to, while Haliotis rufescens is the largest of the genus at.
By weight, about one-third of the animal is edible meat, one-third is offal, and one-third is shell.

Structure and properties of the shell

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. The dust created by grinding and cutting abalone shell is dangerous; appropriate safeguards must be taken to protect people from inhaling these particles.

Species

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 to 130. This list finds a compromise using the "WoRMS" database, plus some species that have been added, for a total of 57. 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.
SpeciesRangeConservation status
Haliotis alfredensis Bartsch, 1915South AfricaNot evaluated
Haliotis arabiensis Owen, Regter & Van Laethem, 2016Off Yemen and OmanNot evaluated
Haliotis asinina Linnaeus, 1758Philippines; Indonesia; Australia; Japan; Thailand; VietnamNot evaluated
Haliotis australis Gmelin, 1791New ZealandNot evaluated
Haliotis brazieri Angas, 1869Eastern AustraliaNot evaluated
Haliotis clathrata Reeve, 1846Seychelles; Comores; Madagascar; Mauritius; KenyaNot evaluated
Haliotis coccoradiata Reeve, 1846Eastern AustraliaNot evaluated
Haliotis corrugata Wood, 1828California, USA; Baja California, MexicoSpecies of Concern National Marine Fisheries Service; Vulnerable and imperiled California Department of Fish and Wildlife
Haliotis cracherodii Leach, 1814California, USA; Baja California, MexicoCR IUCN; Vulnerable California Department of Fish and Wildlife; Listed endangered National Marine Fisheries Service
Haliotis cyclobates Péron & Lesueur, 1816Southern AustraliaNot evaluated
Haliotis dalli Henderson, 1915Galapagos IslandsNot evaluated
Haliotis discus Reeve, 1846Japan; South KoreaNot evaluated
Haliotis dissona Australia; New CaledoniaNot evaluated
Haliotis diversicolor Reeve, 1846Japan; Australia; Southeast AsiaNot evaluated
Haliotis drogini Owen & Reitz, 2012Not evaluated
Haliotis elegans Koch & Philippi, 1844Western AustraliaNot evaluated
Haliotis exigua Dunker, R.W., 1877JapanNot evaluated
Haliotis fatui Geiger, 1999Tonga Mariana IslandsNot evaluated
Haliotis fulgens Philippi, 1845California, USA; Baja California, MexicoVulnerable ; Species of Concern NMFS
Haliotis geigeri Owen, 2014Not evaluated
Haliotis gigantea Gmelin, 1791JapanNot evaluated
Haliotis glabra Gmelin, 1791Philippines; VietnamNot evaluated
Haliotis iris Gmelin, 1791New Zealand; VanuatuNot evaluated
Haliotis jacnensis Reeve, 1846Japan; Nicobar Islands; Ryukyu Islands; Pacific Islands;Not evaluated
Haliotis kamtschatkana Jonas, 1845Western North America
Endangered IUCN; Imperiled, Vulnerable, critically imperiled ; Species of Concern NMFS
Haliotis laevigata Donovan, 1808South Australia; TasmaniaNot evaluated
Haliotis madaka Japan; South KoreaNot evaluated
Haliotis mariae Wood, 1828Oman; YemenNot evaluated
Haliotis marmorata Linnaeus, 1758Liberia; Ivory Coast; GhanaNot evaluated
Haliotis matihetihensis
Haliotis melculus Australia Not evaluated
Haliotis midae Linnaeus, 1758South AfricaNot evaluated
Haliotis mykonosensis Owen, Hanavan & Hall, 2001Greece; Turkey; TunisiaNot evaluated
Haliotis ovina Gmelin, 1791Thailand; Vietnam; southern part of the Pacific Ocean; Andaman Islands; Maldives; Ryukyu IslandsNot evaluated
Haliotis parva Linnaeus, 1758South Africa; AngolaNot evaluated
Haliotis planata G. B. Sowerby II, 1882Ryukyu Islands; Sri Lanka; Indonesia; Fiji; Andaman SeaNot evaluated
Haliotis pourtalesii Dall, 1881Gulf of Mexico; Eastern South America; northern ColombiaNot evaluated
Haliotis pulcherrima Gmelin, 1791PolynesiaNot evaluated
Haliotis queketti E.A. Smith, 1910South Africa; Mozambique; KenyaNot evaluated
Haliotis roei Gray, 1826AustraliaNot evaluated
Haliotis rubiginosa Reeve, 1846Lord Howe Island; Malakula IslandNot evaluated
Haliotis rubra Leach, 1814Southern and Eastern AustraliaNot evaluated
Haliotis rufescens Swainson, 1822Western North AmericaApparently secure ; critically imperiled
Haliotis rugosa Lamarck, 1822South Africa; Madagascar; Mauritius; Red SeaNot evaluated
Haliotis scalaris Southern and Western AustraliaNot evaluated
Haliotis semiplicata Menke, 1843Western AustraliaNot evaluated
Haliotis sorenseni Bartsch, 1940California, USA; Baja California, MexicoCritically imperiled ; Endangered NMFS
Haliotis spadicea Donovan, 1808South AfricaNot evaluated
Haliotis speciosa Reeve, 1846Eastern South AfricaNot evaluated
Haliotis squamosa Gray, 1826Madagascar; Eastern Australia; OkinawaNot evaluated
Haliotis stomatiaeformis Reeve, 1846Malta; Pacific IslandsNot evaluated
Haliotis supertexta Lischke, 1870Japan; Sao TomeNot evaluated
Haliotis thailandis Dekker & Patamakanthin, 2001Andaman SeaNot evaluated
Haliotis tuberculata Linnaeus, 1758Ireland ; Channel Islands; Azores; Canary Islands; Japan; Madeira ; Brittany; Great BritainNot evaluated
Haliotis unilateralis Lamarck, 1822Gulf of Aqaba; East Africa; Seychelles;Not evaluated
Haliotis varia Linnaeus, 1758Mascarene Basin; Red Sea; Sri Lanka; Western Pacific;Not evaluated
Haliotis virginea Gmelin, 1791New Zealand; Chatham Islands; Auckland Islands; Campbell Island; FijiNot evaluated
Haliotis walallensis Stearns, 1899Western North AmericaNot evaluated

Synonyms