Geographic Range
Northern anchovy are found off the west coast of North America, from Queen Charlotte
Islands in British Columbia, Canada, to Cabo San Lucas in Baja California, Mexico,
and in the Gulf of California.
- Biogeographic Regions
- nearctic
- pacific ocean
Habitat
Engraulis mordax
is a neritic, epipelagic species that favors areas of coastal upwelling. Larvae can
be found from 0 to 50 meters in depth, and adults are commonly found between 70 m
and 200 m in depth. Larvae, juveniles, and adults can tolerate water temperatures
between 8 and 25 degrees Celsius.
- Habitat Regions
- temperate
- saltwater or marine
Physical Description
Northern anchovies are small, slightly compressed and have large, inferior mouths.
They are an iridescent bluish-green on the dorsum and shiny silver along the ventral
surface. Adults have a faint silver stripe along their side. The insertion point of
the anal fin can be used to distinguish northern anchovies from other
anchovy
species, as it inserts immediately posterior to the dorsal fin. Average adult size
is 9 g in mass and 7 cm in length, and individuals rarely exceed 10 g in mass and
9 cm in length. Sexual dimorphism has not been reported in this species.
- Other Physical Features
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Development
During the larval period and throughout development, integument and lateral line system
of northern anchovies develop gradually. Their eyes migrate from a binocular orientation
to the sides of the head, and the digestive tract gradually becomes able to digest
proteins. The swim bladder develops expansive capability via muscle differentiation,
and trunk musculature differentiates and develops into two muscle fiber types. Organs
development in northern anchovies can be characterized as initial differentiation
followed by continued development of specialized cell and tissue types. A complete
review of embryological development is provided in O'Connel, 1981.
Reproduction
Northern anchovies are promiscuous, as both sexes spawn indiscriminately with multiple
partners during breeding season.
- Mating System
- polygynandrous (promiscuous)
Northern anchovies breed during late winter and spring, however, some research suggests
that they spawn throughout the year, with peak activity occurring from February to
April. Spawning usually occurs within 95 km of the coast, but has been recorded up
to 480 km offshore. There are approximately 574 eggs per gram, and fertilized eggs
hatch 2 to 4 days after spawning. Northern anchovies perform seasonal migrations,
usually moving to deeper, offshore waters during winter, and returning to shallow,
coastal waters for spring. Males and females become sexually mature at about 2 years
of age.
- Key Reproductive Features
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- broadcast (group) spawning
- oviparous
Northern anchovies are broadcast spawners, and therefore, parental care is nonexistent in this species.
- Parental Investment
- no parental involvement
Lifespan/Longevity
Little information is available concerning the average lifespan of northern anchovies. In the wild, most live between 4 and 7 years, with an average lifespan of 5 years.
Behavior
Northern anchovies create large schools, which aids in antipredator defense and finding
prey. Adult northern anchovies typically attack prey only once and rarely make a second
attempt. Swimming and feeding behavior is dependent on a number of different factors
including temperature, developmental stage, and where they are distributed in the
water column. Northern anchovies perform seasonal migrations, moving to deeper, offshore
waters during winter, and returning to shallow, coastal waters for spring.
Home Range
Engraulis mordax
is a mobile, schooling, pelagic species, and does noes not maintain a home range.
Communication and Perception
Little is known of communication and perception in this species. However, northern
anchovies use vision and chemoreception through nares and the lateral line system
to perceive their environment and communicate with conspecifics.
- Perception Channels
- visual
- tactile
- vibrations
- chemical
Food Habits
Northern anchovies feed upon
krill
,
copepods
, and
decapod
larvae, and collect food via filter feeding and active predation. When filter feeding,
water and zooplankton pass through its large gaping mouth as it swims. Water passing
over the gills is strained through long, finely-separated gill rakers, which collect
particulate organic matter, phytoplankton, and zooplankton. Apart from nonselective
filter feeding, northern anchovies have also been observed 'pecking' at larger prey.
Adult northern anchovies typically attack prey only once and rarely make a second
attempt in the event that prey escape.
Upon sighting prey, northern anchovy larvae assumes an S-shaped posture and advances
toward the prey by sculling its pectoral fins and undulating the fin fold, while maintaining
the S-posture. Larval anchovies maintain prey in the center of their visual field
via slight adjustments in the position of its head and body. When prey are within
striking distance, a larva opens its mouth and straightens its body. This causes the
body to project forward, and the prey is ingested. The entire process takes about
1 to 2 seconds.
- Primary Diet
- planktivore
- Animal Foods
- zooplankton
- Plant Foods
- phytoplankton
- Foraging Behavior
- filter-feeding
Predation
Northern anchovy larvae, while transparent, fall prey to a number of invertebrate
and vertebrate planktivores. As juveniles they acquire pelagic coloration, and are
extremely vulnerable to piscivores such as
albacore
and
chub mackeral
. A wide variety of fish,
seabirds
, and marine
mammals
feed on northern anchovies. They form large schools for protection against predators,
and their coloration may help camouflage them from potential predators.
Humans
are probably the most significant predator of northern anchovies.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Northern anchovies are an important primary and secondary consumer within the epipelagic
food web of the Pacific coast. It is a critical source of food for a great variety
of organisms, such as larger fish, marine mammals, and marine birds. Larvae are an
important component of the spring ichthyoplankton assemblage in coastal California.
Northern anchovies are host to numerous endoparasites, including
protists
(e.g.,
myxosporidian protozoan
),
flatworms
(e.g.,
hemiurid trematodes
and
didymozoid trematodes
, and
digenean flatworms
), and
roundworms
(e.g.,
Anisakis
and
Hysterothylacium
).
- myxosporidian protozoan, Sphaeromyxa reinhardti
- digenean flatworm, Lecithaster gibbosus
- nematodes, Anisakis
- nematodes, Hysterothylacium
- hemiurid trematode, Parahemiurus merus
- didymozoid trematodes, Digenea
Economic Importance for Humans: Positive
Northern anchovies support a number of commercial fisheries and live-bait fisheries
in the United States, Canada, and Mexico. They are commonly consumed by
humans
and are sold live to anglers as bait. They are often converted into feed for fish
hatcheries and farms and are a source of industrial fish meal and oil. From 1916 to
1967, catches averaged 325 metric tons per year. Total population biomass for northern
anchovies was estimated to be 432,000 tons in 1994. Currently, California does not
have an active fishery for this species.
- Positive Impacts
- food
- source of medicine or drug
- produces fertilizer
Economic Importance for Humans: Negative
There are no known adverse effects of Engraulis mordax on humans.
Conservation Status
Based on research by California Department of Fish and Game (CDFG), northern anchovy
landings and exploitation rates since 1983 have been decreasing. While biomass estimates
are unavailable for recent years, CDFG believes the stock is currently stable at a
modest biomass level. Northern anchovies are classified as a species of least concern
on the IUCN's Red List of Threatened Species. Although current populations are thought
to be stable, overfishing presents a potential threat to the longterm persistence
of this species.
Additional Links
Contributors
Tasha Davis (author), San Diego Mesa College, Eriq DelaTorre (author), San Diego Mesa College, Aaron Raub (author), San Diego Mesa College, Paul Detwiler (editor), San Diego Mesa College, John Berini (editor), Animal Diversity Web Staff.
- 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.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- saltwater or marine
-
mainly lives in oceans, seas, or other bodies of salt water.
- pelagic
-
An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).
- coastal
-
the nearshore aquatic habitats near a coast, or shoreline.
- heterothermic
-
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- 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.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- external fertilization
-
fertilization takes place outside the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- natatorial
-
specialized for swimming
- diurnal
-
- active during the day, 2. lasting for one day.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- nomadic
-
generally wanders from place to place, usually within a well-defined range.
- migratory
-
makes seasonal movements between breeding and wintering grounds
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- chemical
-
uses smells or other chemicals to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- vibrations
-
movements of a hard surface that are produced by animals as signals to others
- chemical
-
uses smells or other chemicals to communicate
- zooplankton
-
animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)
- phytoplankton
-
photosynthetic or plant constituent of plankton; mainly unicellular algae. (Compare to zooplankton.)
- filter-feeding
-
a method of feeding where small food particles are filtered from the surrounding water by various mechanisms. Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales.
- cryptic
-
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
- food
-
A substance that provides both nutrients and energy to a living thing.
- drug
-
a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease
- planktivore
-
an animal that mainly eats plankton
References
Baldwin, R. 2010. Using Parasite Community Data and Population Genetics for Assessing Pacific Sardine ( Sardinops sagax ) Population Structure Along the West Coast of North America. Dissertation: Oregon State University , 1/1: 1–207. Accessed May 24, 2011 at http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/18814/Rebecca%20Baldwin%20PhD%20disseration%20OSU%202010.pdf?sequence=11 .
Bergin, D., L. Jacobson. 2001. " http://www.dfg.ca.gov/marine/status/northern_anchovy.pdf " (On-line). California's Living Marine Resources: A Status Report. Accessed May 24, 2011 at http://www.dfg.ca.gov/marine/status/northern_anchovy.pdf .
Hewitt, R. 1985. The 1984 spawning biomass of the northern anchovy. CalCOFI Report , XXVII: 16-24. Accessed May 11, 2011 at http://calcofi.ucsd.edu/newhome/publications/CalCOFI_Reports/v27/pdfs/Vol_27_Bindman.pdf .
Hunter, R., S. Goldberg. 1979. Spawning incidence and batch fecundity in northern anchovy, Engraulis mordax . Fishery Bulletin , 77 No. 3: 641-652. Accessed May 11, 2011 at http://swfsc.noaa.gov/publications/CR/1980/8036.PDF .
Miller, D., R. Lea. 1972. Guide to the Coastal Marine Fishes of California: California Fish Bulletin Number 157 . California: Division of Agriculture and Natural Resources.
O'Connel, C. 1981. Development of organ systems in the Northern anchovy, Engraulis mordax , and other teleosts. American Zoologist , 21: 429-446. Accessed May 16, 2011 at http://swfsc.noaa.gov/publications/CR/1981/8145.PDF .
Picquelle, S., R. Hewitt. 1983. The northern anchovy spawning biomass for the 1982-83 California Fishing season. Northern Anchovy spawning biomass , XXIV: 16-28.
2011. " Engraulis mordax (Girard, 1856)" (On-line). Accessed May 05, 2011 at http://www.fao.org/fishery/species/2107/en .
2011. "Northern Anchovy ( Engraulis mordax )" (On-line). Accessed May 15, 2011 at http://www.nmfs.noaa.gov/fishwatch/species/anchovy.htm .
U.S. Fish and Wildlife Service. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest): Northern anchovy. Biological Report 82(11.50). Lafayette, Louisiana: U.S. Army Corps of Engineers. 1986. Accessed May 05, 2011 at http://www.nwrc.usgs.gov/wdb/pub/species_profiles/82_11-050.pdf .