Abalone Shells of the Haliotidae Family
Four Abalone Shells of the Haliotidae Family can be found in this website:
Phylogeny: Abalone shells of the Haliotidae Family (Rafinesque, 1815), are gastropod mollusks that are in the Order Lepetellida, which are marine mollusks distinguished by their specialize foot that is used for clinging to hard substrates. Haliotidae is the only family in the Superfamily Haliotoidia. The family consists of only one genus – Haliotis, which encompasses seventy species. These shells are also commonly known as Sea-Ears and Haliotids.
Description: Abalone shells have an oval profile with bowl or ear-shaped shells. They are strongly constructed with the body whorl comprising the great majority of the shell. They have a low spire and a very large aperture, comprising almost all of the shell’s underside. The degree of arch on the dorsal surface varies by species. Younger abalone have a flatter profile than mature shells. The exterior of the shell has sculpting ranging from mostly smooth to wavy or spirally ridged. Frequently they are overgrown by marine organisms that cover the shell’s exterior. Abalone have a row of holes along the left edge of the shell that allows circulated water to exit. The number and height of the base of these holes are important in distinguishing species. The interior of these shells is iridescent, colorful, mother-of-pearl. Abalones can produce crude, low value pearls. Abalone do not have an operculum or periostracum. Living animals often display a row of short tentacles (epipodia) between the rock and the shell edge. These tentacles are sensory organs, sensing touch, water movement, and light. The structure and color of the epipodia is another key in determining species identification. They are known to hybridize making species identification difficult. They range in maximum size from 2.5 cm (1.0 inch) to over 30 cm (11.8 inches) in length.
Habitat and Distribution: Abalone cling to rocks by use of a powerful foot muscle. In some cases, hundreds of pounds of force are required to separate the animal from the rock. They are found from the mid-tide region to depths in excess of 365 m (1,200 feet). They are found primarily in the Pacific and Indian Oceans and the Eastern Atlantic but have a global distribution that varies by location. In Mexico, abalone have a limited distribution, and are found only along the west coast of the Baja Peninsula. Six species are found along the Pacific coast of the Baja Peninsula.
Natural History: Abalone are herbivores, grazing on algae. Pigments in the algae determine the color in the shell’s exterior. Abalone are preyed upon by crabs, fish, marine mammals, and predatory mollusks. They are gonochoric and reproduce sexually, through broadcast spawning, with external fertilization. All abalone species are edible and as a result they have been fished throughout much of history. The first recorded mention of abalone was by Aristotle around 400 BC. The first recorded story of abalone fishing comes from Japan on September 12, 425 AD. In this story, a diver named Osahi was trying to collect an abalone pearl for the Emperor. He had a rope tied around his waist for safety. When he didn’t surface, he was pulled to the surface, dead. He was still holding on to a large abalone that contained a pearl the size of a peach. The shell of the abalone has also been valued throughout history, both for its beauty and its usefulness as a bowl. Native Indians along the Baja California and California coastlines made extensive use of abalone and abalone shells have been found in archeological sites as far away as northern Utah and Texas. Abalone shells are also the subjects of modern paintings, dating back to 1604. Abalone are currently fished and farmed along the Baja Peninsula. The earliest commercial abalone fishermen along the Peninsula were the Chinese; they were followed by the Japanese and then the local Mexicans.