Abalone Grading Information
Blacklip Abalone Description
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 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 8 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. Each species has a typical number of open holes, between four and ten, in the selenizone. An abalone has 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. 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. There are about 70 uncini, 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.
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.
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 millimetres (Haliotis pulcherrima) to 200 millimetres while Haliotis rufescens is the largest of the genus at 30 cm.
Abalones are herbivorous on hard substrata.
By weight, approximately one-third of the animal is edible meat, one-third is offal, and one-third is shell
Greenlip Abalone Description
The shell measures up to 18 cm. The species features a distinctive green ring around the foot at the bottom of the shell.
The large, rather thin shell has an oval shape. The distance of the apex from the margin is one-sixth to one-eighth the length of the shell. The shell is nearly smooth but shows obsolete spiral lirae. The coloration is orange or orange-scarlet, radiately striped with continuous white flames. The coloration consistis of continuous oblique stripes of scarlet and whitish. The about 12 perforations are very small. The outline of the shell is oval, with the right and left margins about equally curved. The back of the shell is convex, rounded, and not angulated at the row of perforations. The surface is sculptured with nearly obsolete spiral threads and cords. The spire is moderately elevated. The whorls number about 2½. The inner surface is silvery. The nacre is almost smooth, but shows traces of spiral sulci, and is very minutely wrinkled. The columellar plate is rather wide, sloping inward, flattened, and obliquely truncated at the base. The cavity of the spire is large and rather shallow. The perforations are unusually small, their borders not raised outside.