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Species Database

Haliotis cracherodii - Black Abalone

Black Abalone image

Geographic range:

Coos Bay, Oregon to Cape San Lucas, Baja California, Mexico

Key features:

Smooth, dark black shell. The mantle, epipodium, and tentacles are smooth and black.

Habitat(s):

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

Primary common name:

Black Abalone

General grouping:

Snails, limpets, abalone, chitons

ITIS code:

69498
 

Geographic Range

Range Description:

Haliotis cracherodii can be found from Coos Bay, Oregon to Cape San Lucas, Baja California, Mexico.

Intertidal Height

Lowest intertidal height:

0 meters OR -2 feet

Highest intertidal height:

0.60060060 meters OR 2 feet

Intertidal height notes:

In California, Haliotis cracherodii inhabits the intertidal whereas other abalone species are found almost exclusively in the subtidal.

Subtidal Depth Range

Minimum depth:

0 meters OR 0 feet

Maximum depth:

6.00600600 meters OR 20 feet

Subtidal depth notes:

Haliotis cracherodii can occasionally be found subtidally.

Habitats

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

Habitat notes:

Haliotis cracherodii usually inhabits deep crevices in rocks between the high and low tide lines. This abalone can be found subtidally, but usually only to about 6 m deep. Under normal conditions, they can also be found on or under rocks crowded close together and even stacked on top of each other.

Abundance

Relative abundance:

Haliotis cracherodii was abundant in the past, though now it is rare. Following completion of an Endangered Species Act (ESA) status review for black abalone (Haliotis cracherodii), NOAA\'s National Marine Fisheries Service (NMFS) published a proposed rule to list black abalone as endangered on January 11, 2008. After considering public comments on the proposed rule, NMFS issued a final rule to list black abalone as endangered under the ESA, published in the Federal Register on January 14, 2009. This will be effective as of February 13, 2009.

Species Description

General description:

Haliotis cracherodii was once one of the most abundant mollusks on the Pacific Coast of North America. Now, because of intense fishing and the withering syndrome, it has become incredibly rare. Haliotis cracherodii belongs to the family Haliotidae in the class Gastropoda, shared by all snails and slugs, in the phylum Mollusca. All abalones belong to the genus Haliotis which is the only genus in the family Haliotidae. Worldwide, there are about 130 species, subspecies and hybrids belonging to this genus. A flattened ear shaped shell distinguishes abalones from other gastropods and imparts their genus name, Haliotis, which literally means sea ears. This shell is prized for its beautiful iridescent inner layer that is more commonly known as mother of pearl.

Distinctive features:

Haliotis cracherodii has a very smooth outer shell that is dark blue to greenish black. The epipodium and tentacles are black and smooth. The bluntly oval shell is usually epiphytic free. The interior of the shell is pearly with pink and green iridescence and no muscle scar. The shell has five to nine open holes that are flush with the shell surface. Occasionally shells may lack holes altogether. A subspecies found on Guadalupe Island, Baja California, Haliotis cracheroidii californiensis, has 12 to 16 small open holes.

Haliotis cracherodii has a smoother and darker shell than most other abalone species. Haliotis rufescens has a larger shell that is more red in color and Haliotis walallensis has a considerably flattened shell that is red with mottlings of greenish blue and white.

Size:

Haliotis cracherodii can grow to a size of about 200 mm, but most are 75 – 125 cm.

Natural History

General natural history:

Haliotis cracherodii populations have suffered incredibly from a chronic, progressive and lethal disease referred to as the Withering Syndrome, or Abalone wasting disease. This disease was first described in 1986 and is caused by the bacterium Candidatus xenohaliotis californiensis, which attacks the lining of the abalone’s digestive tract and inhibits the production of digestive enzymes. The abalone is forced to consume its own body mass, causing its foot to whither and atrophy. The abalone loses its ability to adhere to rocks and becomes incredibly vulnerable to predation and starvation. Commercial and recreational fishing have also played a role in decreased population size, especially after other abalone species were overfished. However, since this disease was first observed in parts of central and southern California, abalone populations have declined by nearly 99 percent. Thus the California fishery for Haliotis cracherodii closed in 1993. The Red Abalone, Haliotis rufescens, also suffers from Withering Syndrome. Recovery for Haliotis cracherodii will likely be a long term process due to low population numbers, low recruitment, and slow growth.

Haliotis cracherodii grows considerably in the first two years nearly reaching 30 mm in length by the end of their first year and 55 mm by the end of their second year. This rate can continue for a year or two if food is highly available, but then slows to only 4 mm a year or less after individuals reach 90 mm in length. Increased temperatures have been shown to increase feeding and growth in abalone, however, warmer temperatures have also been shown to increase the spread of the bacterium that causes the Withering Syndrome.

Predator(s):

Sea otters, Enhydra lutris, sea stars, fishes and octopi feed on Haliotis cracherodii.

Prey:

Haliotis cracherodii feeds mostly on large brown algae.

Feeding behavior

Herbivore

Feeding behavior notes:

Small individuals graze on diatoms and corallines, while larger ones feed on pieces of drift algae trapped in their crevices or captured by foot. Haliotis cracherodii may also graze algae from the backs of their neighbors which may be why the shell of the black abalone is so smooth and shiny.

July - September

Reproduction:

Haliotis cracherodii spawns sometime during the late summer in the Monterey area. The release of gametes is fairly synchronous with a population. However populations separated by as little as 11 km may spawn several weeks apart.

Monterey Bay National Marine Sanctuary:

Becoming increasingly rare as Withering Syndrome (WS) increases in more northern populations.

Listing Status:

Following completion of an Endangered Species Act (ESA) status review for black abalone (Haliotis cracherodii), NOAA\'s National Marine Fisheries Service (NMFS) published a proposed rule to list black abalone as endangered on January 11, 2008. After considering public comments on the proposed rule, NMFS issued a final rule to list black abalone as endangered under the ESA, published in the Federal Register on January 14, 2009. This will be effective as of February 13, 2009.
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.
Cox, Keith W. 1962. California abalones, family Haliotidae. California Department of Fish and Game Fish Bulletin 118: 1 - 133
Gotshall, D. 2005. Guide to marine invertebrates : Alaska to Baja California. Sea Challengers, Monterey, CA. 117 p.
MARINe. 2004 (Updated 12/09/04). Multi-Agency Rocky Intertidal Network. World Wide Web electronic publication, http://www.marine.gov, Accessed [04/22/06]
Meinkoth, N.A. 1998. National Audubon Society Field Guide to North American Seashore Creatures. A.A. Knopf, New York, NY. 813 p.
Ricketts, E. F., J. Calvin, and J.W. Hedgpeth. 1985. Between Pacific tides. Stanford University Press, Stanford, CA. 652 p.
Rocky Entries. 2006 (Updated 08/12/06). Abalone. World Wide Web electronic publication. http://www.sonic.net/~rocky/abalone.htm, Accessed [09/15/06].
VanBlaricom, G., M. Neuman, J. Butler, A. DeVogelaere, R. Gustafson, C. Mobley, D. Richards, S. Rumsey, and B. Taylor. 2009. Status review report for Black Abalone (Haliotis cracherodii Leach, 1814). NMFS Southwest Region, 501 West Ocean Boulevard, Suite 4200, Long Beach, CA 90802. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service.