California mussel
Encyclopedia
The California mussel, Mytilus californianus, is a large edible mussel
, a marine
bivalve
mollusk in the family Mytilidae
.
This species is native to the west coast of North America
, occurring from northern Mexico
to the Aleutian Islands of Alaska
. California mussels are found clustered together, often in very large aggregations, on rocks in the upper intertidal zone
on the open coast, where they are exposed to the strong action of the surf.
which is usually worn off except near the growing edge of the shell. The beaks of the shell are often eroded. The shell has coarse radial ribbing and irregular growth lines on the outer surface. The inner surface of the shell is blue and faintly pearly.
Like other mytilids, the animal is attached to the substrate with a very strong and elastic byssus
.
, low sediment
conditions found on open rocky coasts. However, they do not colonize
bare rock easily, instead preferring the shelter of pre-existing mussels and their biological filaments. Mussels attach themselves to the hard surfaces using their thread-like byssus
.
Given the right circumstances, California mussels can grow up to 200 mm (8 inches) in length and may live for more than 20 years. However, mortality in intertidal open coastal environments is often high, resulting from battering from driftwood
and other debris, wave
pounding, predation
, desiccation
, and disease
. Predators of California mussels include the Pisaster
starfish. Their most common food is Phytoplankton
.
who lived on the Pacific Coast prior to European contact. On California's Northern Channel Islands, archaeological evidence shows that they were harvested continuously for almost 12,000 years. Erlandson et al. (2008) documented a decline in the average size of harvested California mussels on San Miguel Island
during the past 10,000 years, a pattern they attributed to growing human populations and increased predation pressure from human fishing. Hogan (2008) notes more specific archaeological recovery from the Chumash in the period 800 to 1300 AD.
California mussels continue to be harvested as sources of both food and bait up and down the Pacific Coast of North America. The flesh of the California mussel tends to be orange in color. They can be baked, boiled, or fried like other mussel
s, clam
s, and oyster
s.
While these mussels are usually edible, care needs to be taken, because during times of red tide
in any given locality, California mussels may contain harmful levels of the toxins which can cause paralytic shellfish poisoning
.
concept was coined, in 1969, by the zoologist Robert T. Paine
, professor emeritus of the University of Washington
, to explain the relationship between Pisaster ochraceus, a species of starfish, and Mytilus californianus.
Mussel
The common name mussel is used for members of several families of clams or bivalvia mollusca, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...
, a marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
bivalve
Bivalvia
Bivalvia is a taxonomic class of marine and freshwater molluscs. This class includes clams, oysters, mussels, scallops, and many other families of molluscs that have two hinged shells...
mollusk in the family Mytilidae
Mytilidae
Mytilidae is a family of small to large saltwater mussels, marine bivalve mollusks in the order Mytiloida. It is the only family in the order...
.
This species is native to the west coast of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, occurring from northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
to the Aleutian Islands of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
. California mussels are found clustered together, often in very large aggregations, on rocks in the upper intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
on the open coast, where they are exposed to the strong action of the surf.
Shell description
The shell of this species is thick and is often 80 to 130 mm in length, sometimes larger still. The shell is blue on the outside with a heavy brown periostracumPeriostracum
The periostracum is a thin organic coating or "skin" which is the outermost layer of the shell of many shelled animals, including mollusks and brachiopods. Among mollusks it is primarily seen in snails and clams, i.e. in bivalves and gastropods, but it is also found in cephalopods such as the...
which is usually worn off except near the growing edge of the shell. The beaks of the shell are often eroded. The shell has coarse radial ribbing and irregular growth lines on the outer surface. The inner surface of the shell is blue and faintly pearly.
Like other mytilids, the animal is attached to the substrate with a very strong and elastic byssus
Byssus
Byssus means both a silky filament by which certain molluscs attach themselves to hard surfaces, and a rare fabric, also called sea silk and its fibre source.-Word:...
.
Ecology
The California mussel prefers the high salinitySalinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
, low sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
conditions found on open rocky coasts. However, they do not colonize
Colony (biology)
In biology, a colony reference to several individual organisms of the same species living closely together, usually for mutual benefit, such as stronger defense or the ability to attack bigger prey. Some insects live only in colonies...
bare rock easily, instead preferring the shelter of pre-existing mussels and their biological filaments. Mussels attach themselves to the hard surfaces using their thread-like byssus
Byssus
Byssus means both a silky filament by which certain molluscs attach themselves to hard surfaces, and a rare fabric, also called sea silk and its fibre source.-Word:...
.
Given the right circumstances, California mussels can grow up to 200 mm (8 inches) in length and may live for more than 20 years. However, mortality in intertidal open coastal environments is often high, resulting from battering from driftwood
Driftwood
Driftwood is wood that has been washed onto a shore or beach of a sea or river by the action of winds, tides, waves or man. It is a form of marine debris or tidewrack....
and other debris, wave
Ocean surface wave
In fluid dynamics, wind waves or, more precisely, wind-generated waves are surface waves that occur on the free surface of oceans, seas, lakes, rivers, and canals or even on small puddles and ponds. They usually result from the wind blowing over a vast enough stretch of fluid surface. Waves in the...
pounding, predation
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
, desiccation
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...
, and disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
. Predators of California mussels include the Pisaster
Pisaster
Pisaster is a genus of Pacific sea stars that includes three species, P. brevispinus, P. giganteus, and P. ochraceus. Their range extends along the Pacific coast from Alaska to southern California in the intertidal zone. Pisasters can reach up to in width and typically have five arms...
starfish. Their most common food is Phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
.
Human use
California mussels were an important food source for the Native AmericansIndigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
who lived on the Pacific Coast prior to European contact. On California's Northern Channel Islands, archaeological evidence shows that they were harvested continuously for almost 12,000 years. Erlandson et al. (2008) documented a decline in the average size of harvested California mussels on San Miguel Island
San Miguel Island
San Miguel Island is the westernmost of California's Channel Islands, located across the Santa Barbara Channel in the Pacific Ocean, within Santa Barbara County, California. San Miguel is the sixth-largest of the eight Channel Islands at , including offshore islands and rocks. Prince Island, off...
during the past 10,000 years, a pattern they attributed to growing human populations and increased predation pressure from human fishing. Hogan (2008) notes more specific archaeological recovery from the Chumash in the period 800 to 1300 AD.
California mussels continue to be harvested as sources of both food and bait up and down the Pacific Coast of North America. The flesh of the California mussel tends to be orange in color. They can be baked, boiled, or fried like other mussel
Mussel
The common name mussel is used for members of several families of clams or bivalvia mollusca, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...
s, clam
Clam
The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...
s, and oyster
Oyster
The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....
s.
While these mussels are usually edible, care needs to be taken, because during times of red tide
Red tide
Red tide is a common name for a phenomenon also known as an algal bloom , an event in which estuarine, marine, or fresh water algae accumulate rapidly in the water column and results in discoloration of the surface water. It is usually found in coastal areas...
in any given locality, California mussels may contain harmful levels of the toxins which can cause paralytic shellfish poisoning
Paralytic shellfish poisoning
Paralytic shellfish poisoning is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks . These shellfish are filter feeders and, therefore, accumulate toxins produced by microscopic algae, such as...
.
In science
The keystone speciesKeystone species
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and...
concept was coined, in 1969, by the zoologist Robert T. Paine
Robert T. Paine (zoologist)
Robert T. Paine, PhD, is a zoologist and professor emeritus of the University of Washington,who coined the keystone species concept in order to explain the relationship between Pisaster ochraceus, a species of starfish, and Mytilus californianus, a species of mussel.In his classic 1966 paper, Dr...
, professor emeritus of the University of Washington
University of Washington
University of Washington is a public research university, founded in 1861 in Seattle, Washington, United States. The UW is the largest university in the Northwest and the oldest public university on the West Coast. The university has three campuses, with its largest campus in the University...
, to explain the relationship between Pisaster ochraceus, a species of starfish, and Mytilus californianus.
Sources
- Erlandson, Jon M., T.C. Rick, T.J. Braje, A. Steinberg, & R.L.Vellanoweth. 2008. Human Impacts on Ancient Shellfish: A 10,000 Year Record from San Miguel Island, California. Journal of Archaeological Science 35:2144-2152.
- C. Michael Hogan, Los Osos Back Bay, Megalithic Portal, ed. Andy Burnham (2008)
- Schmidt, D., A Review of California Mussel ("Mytilus californianus") Fisheries Biology and Fisheries Programs, Canadian Stock Assessment Secretariat Research Document 99/187 (PDF)
- McLean, James. 1969. Marine Shells of Southern California, Los Angeles County Museum of Natural History