Learn about Abalone shellfish, Abalone seafood

Abalone Sea Creature Classification

Abalone belong to the phylum Mollusca, a group which includes clams, scallops, sea slugs, octopuses and squid. Mollusks are world wide and predominantly marine. They have a soft body surrounded by a mantle, an anterior head and a large muscular foot. Mollusks are best known for their beautifully formed and colored calcareous shell secreted by the mantle.

The abalone join other snails, whelks and sea slugs in the class Gastropoda. Members of this class have one shell, as opposed to clams with two, (or the shell may be lacking altogether, as in the sea slugs). The spiral structure, so common in snail shells, is flattened in the abalone and may be obscured by fouling and shell boring organisms. Abalone are members of the family Haliotidae and the genus haliotis, which means sea ear, referring to the flattened shape of the shell. The name abalone is probably derived from the Spanish-American word aulon or aulone.

Abalone Shell

The most conspicuous part of any abalone is the shell, with its row of respiratory pores. Shells are prized because of their inner, iridescent layer. The muscular foot has a strong suction power permitting the abalone to clamp tightly to rocky surfaces. A column of shell muscle attaches the body to its shell. The mantle circles the foot as does the epipodium, a sensory structure and extension of the foot which bears tentacles. The epipodium projects beyond the shell edge in the living animal. The epipodium surface may be smooth or pebbly in appearance and its edge may be frilly or scalloped. It is the most reliable structure for identifying abalone species.

The shell of abalones is convex, rounded to oval in shape, and may be highly arched or very flattened. The shell of the majority of species has 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.

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

The animal has fimbriated head lobes and side lobes that are fimbriated and cirrated. The radula has small median teeth, and the lateral teeth are single and beam-like. They have about 70 uncini, with denticulated hooks, the first four very large. The rounded foot is very large in comparison to most molluscs. 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.

Abalone Reproduction

Abalones reach maturity at a relatively small size. Their fecundity is high and increases with their size, laying 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.

The adults provide no further assistance to the larvae and they are described as lecithotrophic. The adults are herbivorous and feed with their rhipidoglossan radula on macroalgae, preferring red or brown algae.

Abalone Seafood

The meat (foot muscle) of abalone is used for food, and the shells of abalone are used as decorative items and as a source of mother of pearl for jewelry, buttons, buckles, and inlay.

Abalones have long been a valuable food source for humans in every area of the world where a species is abundant. The meat of this mollusk is considered a delicacy in certain parts of Latin America (particularly Chile), France, New Zealand, East Asia and Southeast Asia. In the Greater China region and among Overseas Chinese communities, abalone is commonly known as bao yu, and sometimes forms part of a Chinese banquet. In the same way as shark fin soup or bird’s nest soup, abalone is considered a luxury item, and is traditionally reserved for special occasions such as weddings and other celebrations. However, the availability of commercially farmed abalone has allowed more common consumption of this once rare delicacy.