(Translated by https://www.hiragana.jp/)
ADW: Haliotis kamtschatkana: INFORMATION

Haliotis kamtschatkana

Geographic Range

The northern abalone can be found along the Pacific coast of North America, ranging from Baranof Island, Alaska, south to Point Conception, California.

Habitat

The most densely populated areas of northern abalone have rocky substrates, moderate exposure, and moderate algal presence. Kelp forests are home to large numbers of northern abalone, but animals living in these habitats, on average, are smaller.

Physical Description

The northern abalone have are on average 10 to 13 cm when full grown. The outside of the shell appears corrugated, and the spiral is fairly high compared to other abalone. There are four to five holes, which have raised edges.

Reproduction

Haliotis kamtschatkana do not mate. Reproduction is through external fertilization. Males and females synchronize the release of gametes, normally between April and June. There is a larval stage that begins after the egg has been fertilized and lasts for about 48 hours.

Behavior

Northern abalone are slow moving, slow growing animals. Metabolic rates are influenced by temperatures. Grazing and reproduction occupy most of the life of an abalone. The dispersion of abalone populations tends to depend on food accessibility and habitat structure.

Food Habits

Northern abalones are strict vegetarians, as are all other abalones. The most common feeding technique, especially for juveniles, is grazing for coraline algae. As individuals grow, their preference shifts to the entrapment of drifting algae. Northern abalone also graze in California's kelp forests.

Economic Importance for Humans: Positive

Northern abalone are a source of profit for commercial fisheries within their range. Also, their mere existence attracts divers, who hunt them recreationally and bring money to tourist industries and governmental licensing agencies. Abalone shells are commonly used for jewelery.

Conservation Status

Northern abalone are sought after by commercial fisheries, Native Indian groups, and recreational divers. Northern abalone are protected in Canada by the Species at Risk Act (SARA).

Other Comments

Haliotis rufescens, or the red abalone, and the red sea urchin are two most serious competitors of northern abalone among algal grazers. The most lethal enemy to the northern abalone, besides human beings, is the sea otter, Enhydra lutris. Sea otters have made a recent comeback after near extinction. The popualation of H. kamtschatkana flourished while sea otters were rare. Scuba divers are not allowed to use suction or pointed devices while hunting the abalone.

Contributors

Jesse Thomas (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

coastal

the nearshore aquatic habitats near a coast, or shoreline.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

external fertilization

fertilization takes place outside the female's body

fertilization

union of egg and spermatozoan

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

References

Abbott, R. 1954. American Seashells. New York: D. Van Nostrand Company, Inc..

Sloan, N., P. Breen. 1988. Northern abolone, Haliotis kamtschatkana in British Columbia: fisheries and synopsis of life history information. Can. Spec. Publ. Fish. Aquat. Sci., 103: 1-46.