- Abalones attach to rocky surfaces with extremely strong suction applied at their foot.
Their ventilating stream enters just above the foot, and rather than a slit arrangement
for the exiting waste stream, they use several of the most recent holes along the edge of
the shell (the remaining holes are usually plugged). Abalones have rather elaborate
secondary gill structures all along the upper edge of the foot, as shown in the live
mollusc picture below. They feed exclusively on green algae.
- Highly prized as food, the slow-growing, temperate water abalone, Haliotis rufescens, is today scarce from over-harvesting. The Tropical Abalone is rapid growing and a plentiful resource in Southeast Asia; Japanese chefs find little if any difference in taste.
- Abalones look very different in general shape, but they as well as several other clades, namely top shells, slit shells,
true limpets and keyhole
limpets, all share a common evolutionary ancestry. These various groups comprise the Order: Archaeogastropoda. They are all
spirally coiled, top-shaped or somewhat
flattened, and have a wide aperture pressed close to the ground. The limpet shell is
coiled in immature forms although it shows a loss of coiling in the adult. Furthermore, all still show
some vestiges of a primitive bilateral symmetry (i.e., paired gills, paired glands, paired
kidneys, etc.). Torsion is also reduced, unlike the strong torsion seen in more advanced
gastropod orders, where loss of the right gill and right hand portions of other paired
organs are common.
Single Genus: Haliotis
- Class: Gastropoda
- Clade: Vetigastropoda
- Superfamily: Haliotoidea
- Family: Haliotidae
Haliotis rufescens (Swainson, 1822)
Haliotis assinina (Tahil & Junio-Menez, 1999)
Donkey's Ear (Tropical) Abalone
Note secondary gills largely covering shell
in this picture of a live abalone.
(Photo courtesy of Barry Wilson, 1993)