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Species Database

Haliotis rufescens - Red Abalone

Red Abalone image

Geographic range:

Sunset Bay, Oregon to Bahia Tortugas, Baja California, Mexico

Key features:

Lip of the shell is bright red, the mantle is mostly black, and the epipodial tentacles are long and black.

Similar species:

Haliotis walallensis -- Flat abalone
Haliotis kamtschatkana -- Pinto abalone


bay (rocky shore), exposed rocky shore, kelp forest, protected rocky shore

Primary common name:

Red Abalone

General grouping:

Snails, limpets, abalone, chitons

ITIS code:


Geographic Range

Range Description:

Haliotis rufescens can be found from Sunset Bay, Oregon to Bahia Tortugas, Baja California, Mexico.

Intertidal Height

Lowest intertidal height:

0 meters OR -2 feet

Highest intertidal height:

0 meters OR -1 feet

Intertidal height notes:

Haliotis rufescens can be found from the low intertidal to 180 m in depth.

Subtidal Depth Range

Minimum depth:

0 meters OR 0 feet

Maximum depth:

180 meters OR 0 feet

Subtidal depth notes:

Haliotis rufescens can be found throughout the subtidal.


bay (rocky shore), exposed rocky shore, kelp forest, protected rocky shore

Habitat notes:

Haliotis rufescens lives on rocks and in crevices exposed to heavy surf from the low-tide line to water 180 m deep. It is only occasionally found moving across sand or gravel bottoms.


Relative abundance:

Haliotis rufescens is most abundant subtidally on the central California coast between Mendocino County and San Luis Obispo. Specimens are now rare in the intertidal likey as a result of over harvesting.

Species Description

General description:

Haliotis rufescens is a member of the Family Haliotididae in the Class Gastropoda. It is the largest abalone in North America and is greatly favored by Sea Otters, Enhydra lutris and humans alike. It commands high prices and is the most sought after abalone for its highly prized meat.

Distinctive features:

Haliotis rufescens is easily distinguished by its great size and the three or four open and elevated apertures in its shell. Occasionally there can be more or less apertures and older apertures may be sealed off. The shape of its shell is overall somewhat flattened and beret-shaped. The color is brick-red with occasionally bands of green or white and the inner surface is iridescent blue, green, and pinkish. The head, tentacles, scalloped mantle and mantle tentacles are black and it has a prominent muscle scar. The shell itself is rough, with broad, wavelike ridges and fine spiral threads and is often overgrown by forests of hydroids, bryozoans, and plants. The shell may also be pitted by boring sponges, Cliona celata, and boring clams such as Penitella conradi.

The Japanese Abalone, Haliotis kamtschatkana, can be differentiated from Haliotis rufescens since it is a smaller species only reaching 15 cm in length and 108 mm in width. Also, Haliotis kamtschatkana’s shell is highly arched, with 5 open holes and a corrugated surface. It range overlaps with Haliotis rufescens only in central California. The Black Abalone, Haliotis cracherodii is also a smaller sized abalone when compared to Haliotis rufescens and reaches the same size as Haliotis kamtschatkana. However Haliotis cracherodii has 8 open holes and a bluish or greenish-black shell. Also, it usually inhabits deep crevices in rocks, and usually lives from between high-and low-tide lines to water 6 m deep.


Haliotis rufescens can grow to be 30 cm long, 24 cm wide and 76 mm high.

Natural History

General natural history:

Haliotis rufescens has been prized throughout human history for its beautiful iridescent shell which was used in jewelry and more recently for its high quality meat. The legal size the abalone must be in order to harvest by commercial or sport fishermen is 175 mm. There is no legal limit for Enhydra lutris however, and in their range, Haliotis rufescens is seldom found outside of inaccessible crevices. Enhydra lutris and humans have both been responsible for over harvesting Haliotis rufescens and they are scarce in places they were once common as a result. The commercial catch continues to decline, as it has for the past several decades.

Haliotis rufescens is relatively slow growing as it may take 12 to 14 years to reach legal size. However under ideal conditions, growth rates may be at least twice as fast as this. Growth also slows with increasing size and age, and animals approaching full size may be well over 20 years old. As the abalones grow and secret new shell, their diet strongly influences the color. When individuals eat only brown or green algae, their shell will appear more greenish or white. Only when red algae are a significant part of their food source is the shell red or brownish and then this will only be reflected in the part of the shell being secreted at the time. Haliotis rufescens often does consume at least some red algae most of the time and therefore their shell is usually pinkish to red, however distinct bands of color can reflect seasonal or other changes in diet.

Haliotis rufescens often occurs in aggregations and clings to rocks with its great muscular foot. If these abalones are taken unaware, they may be loosened from their location easily, however, once they have clamped down with their foot, a leverage bar is required to dislodge them. This ability to suction onto rocks is the abalone’s main means of defense against predators. The strong foot also makes Haliotis rufescens capable of significant movement. Even so, they usually remain stationary, occupying crevices or other suitable spots and may remain in the same area their entire life. As a result of their sedentary lifestyle, they can easily become covered with marine growths and serve as refuges for other small creatures. An individual shell may support a community of algae, sponges, barnacle, bryozoan and hydroids. In fact, as many as 90 species of small gastropods have been found living on Haliotis rufescens shells. However, if it is pursued by predatory seastars, Haliotis rufescens will actively move away by shuffling forward on its massive muscular foot.

Haliotis rufescens does not have a brain. Instead its nervous system consists of a nerve center with nerve chords, leading to ganglia, which control the animal’s movements. It does have eyes, however, they can only detect vague contrasts between light and dark. The distinctive apertures on the abalone’s shell are its means to discharge water that has been used by the gills.


Haliotis rufescens is preyed heavily upon by humans and Southern Sea Otters, Enhydra lutris nereis, but also be a variety of other animals including crabs, such as Cancer antennarius, octopus, fishes, and seastars, such as the Sunflower Star Pycnopodia helianthoides and the Ochre Star Pisaster ochraceus.


Haliotis rufescens is strictly an herbivore, feeding primarily on attached or drifting macroalgae, and in particular drift kelp. Young abalones graze on surface films of microscopic plants, whereas larger animals eat mainly larger algae.

Feeding behavior


Feeding behavior notes:

Young Haliotis rufescens graze on surface films of microscopic plants, whereas larger animals eat mainly larger algae. Though larger abalones are capable of considerable movement and could seek out algae, they usually remain sedentary and use their foot to capture loose blades as they drift by. Once the drift is caught, it is shredded by the abalone’s small rasplike teeth on the radula, a belt-like \'tongue\'.

January - December


Haliotis rufescens reaches sexual maturity relatively young, probably within four years, at a size of about 13 cm, and fecundity is high. In their first breeding season individuals may produce only a few thousand gametes, but a specimen 15 cm in length may produce several million. The sexes are separate and the spawning of gametes, white sperm or gray-green eggs, have been recorded throughout the year, but tend to be greater in the spring, specifically from February to April. After 10 days, the free-swimming larvae, called veligers, settle to the bottom. The settling is induced by compounds released by coralline algae, upon which the young abalones graze. Within 2 months they develop into tiny adults. Spawning may be triggered by several conditions, such as a sudden change in water temperature, exposure to air for 1 to 2 hours, or rough handling.
Click on an image below to view a larger version in the SIMoN Photo Library. You will also be able to view important information on each photo such as photographer, date, caption and more.
Alden, P., F. Heath, R. Keen, A. Leventer, and W. Zomlefer. 2002. National Audubon Society Field Guide to California. A.A. Knopf, New York, NY.
Cowles, D. 2005. World Wide Web electronic publication., Accessed [06/02/06].
Gotshall, D. 2005. Guide to marine invertebrates : Alaska to Baja California. Sea Challengers, Monterey, CA. 117 p.
Meinkoth, N.A. 1998. National Audubon Society Field Guide to North American Seashore Creatures. A.A. Knopf, New York, NY. 813 p.
Middlebrook, C. 1999. Haliotis rufescens, Animal Diversity Web. World Wide Web Electronic Publication., Accessed [08/18/06].
Ricketts, E. F., J. Calvin, and J.W. Hedgpeth. 1985. Between Pacific tides. Stanford University Press, Stanford, CA. 652 p.