Species description

Pacific bonito, ''Sarda lineolata'', is a marine species of

bonito Bonitos are a tribe of medium-sized, ray-finned, predatory fish in the family Scombridae, which it shares with the mackerel, tuna, and Spanish mackerel tribes, and also the butterfly kingfish. Also called the tribe Sardini, it consists of ...

that is a game fighter but not highly thought of as a food fish. Sarda ''lineolata'' was thought to be a subspecies of Sarda ''chiliensis'' due to the large separation in their range. However, genetic analysis has shown that they are likely the same species. This fish has been mostly found schooling in the open ocean and live up to depths of 110 meters. It is colored

blue Blue is one of the three primary colours in the RYB color model, RYB colour model (traditional colour theory), as well as in the RGB color model, RGB (additive) colour model. It lies between Violet (color), violet and cyan on the optical spe ...

violet Violet may refer to: Common meanings * Violet (color), a spectral color with wavelengths shorter than blue * One of a list of plants known as violet, particularly: ** ''Viola'' (plant), a genus of flowering plants Places United States * Vi ...

above, with metallic luster becoming silvery

ventrally Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

. It has ten or eleven stripes on its back running obliquely from the dorsum forward, and fifteen or more rakers below the angle on the first

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

. The first

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

is contiguous with the second and longer than the head. The

caudal peduncle Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

is slender, and the body entirely scaled. It has no teeth on the

vomer The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms ...

. It has a small

keel The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a fluid dynamics, hydrodynamic and counterbalancing purpose as well. The keel laying, laying of the keel is often ...

on either side of the median keel on the sides of the caudal peduncle, and six to eight

finlet Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only b ...

s on the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

and

ventral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

surfaces of the

. The maximum length is about 40 inches and weight 25 pounds. Females are larger than males at maturity at around 55 cm vs 50 cm. However, males reach maturity around two years sooner.Black G. 1979. Maturity and spawning of the pacific bonito, Sarda chiliensis lineolata, in the Eastern North Pacific. California Department of Fish and Game Marine Resources Technical Reports 41. 60 p. There are no external differences between males and females of any Sarda.Yoshida H. O. 1980. Synopsis of Biological Data on Bonitos of the Genus Sarda. US Department of Commerce. 17. When off the California coast, it is easy to identify these fish because they are the only tuna-like fish in this area that have dark slanted stripes on their dorsal side.California Department of Fish and Wildlife. CA Marine Species Portal. (n.d.). Retrieved October 17, 2024, from https://marinespecies.wildlife.ca.gov/pacific-bonito/the-species/

Distribution

The Pacific bonito has two separate populations with different ranges. The Northern population is typically found between Southern California and Central Baja California. However, they can be found as far North as Southern Alaska in warmer years.Collins R., Huppert D., Maccall A., Radovich J., and Stauffer G. 1980. Pacific Bonito Management Information Document. Marine Resources Technical Report No. 44. 93 p. The Southern population can be found off the coast of Northern Peru to Chile. The species can be found up to several hundred miles off the coast, but is most abundant in areas 15 miles or less off the coast.California Department of Fish and Game (CDFG). 2010. Status of the Fisheries Report: An Update Through 2008. Chapter 9 Pacific Bonito, Sarda chiliensis. 153 p.

Behavior

Pacific bonito usually travel in

schools A school is the educational institution (and, in the case of in-person learning, the building) designed to provide learning environments for the teaching of students, usually under the direction of teachers. Most countries have systems of ...

. This species migrates up the coast with the seasons. They can migrate up to 600 miles and move south in the winter where temperatures are warmer and north for the summer.

Diet

Fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

and

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

are its main diet. Bonitos were found to eat primarily Northern Anchovy. They have also been known to eat rockfish, hake, sardines, saury and mackerel. From January to June, during their spawning season, they have been found to eat equal amounts of mackerel and squid.

Conservation status

Pacific bonito are a fast-growing species which makes them more resilient to overfishing. Currently, their population is believed to be in stable condition. Not much information on their status is currently known though and more research will need to be done to know for sure. Estimating the populations of this species is also difficult due to them moving around a lot and quickly.

Human interactions and ecosystem role

It is caught by

trolling In slang, a troll is a person who posts deliberately offensive or provocative messages online (such as in social media, a newsgroup, a internet forum, forum, a chat room, an Multiplayer video game, online video game) or who performs similar be ...

and still

fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (Freshwater ecosystem, freshwater or Marine ecosystem, marine), but may also be caught from Fish stocking, stocked Body of water, ...

, using feather lures,

spoons Spoons may refer to: * Spoon, a utensil commonly used with soup * Spoons (card game), the card game of Donkey, but using spoons Film and TV * ''Spoons'' (TV series), a 2005 UK comedy sketch show *Spoons, a minor character from ''The Sopranos' ...

, or live

bait Bait may refer to: General * Bait (luring substance), bait as a luring substance ** Fishing bait, bait used for fishing Film * ''Bait'' (1950 film), a British crime film by Frank Richardson * ''Bait'' (1954 film), an American noir film by Hugo ...

. Although there is not a lot of information about this species’ role in the ocean, it does serve as a food source for predators such as swordfish, bluefin tuna, striped marlin, sea lions, and dolphins as well as some sharks.

Habitat

Mature Pacific bonito are most commonly found in open ocean environments of up to 300 ft and swim in schools. Younger individuals are more often found in kelp forests where they have places to hide. There is evidence to suggest younger individuals may even be found in harbors and bays.

Lifecycle and reproduction

Pacific bonito have an average lifespan of 6-8 years in the wild. Pacific bonito males reach sexual maturity at one year old whereas it takes females to 3 years to reach sexual maturity. This species has been observed performing some courtship behavior and has been observed releasing gametes simultaneously after swimming together in a circle. Pacific bonito can spawn multiple years and begin spawning earlier in the season the older they get. They produce eggs which are free floating and take around three days to hatch. They exhibit slight sexual dimorphism during mating and courtship, but only during those times and are otherwise indistinguishable.Magnuson J. J. and Prescott J. H. 1966. Courtship, location, feeding and miscellaneous behaviour of Pacific Bonito. Animal Behaviour 14: 54–67.

Impacts of climate change

In typical years, the Northern part of this species’ population resides in Southern California during spring and summer. They can be found farther north during El Nino, but not during normal years. The changing climate may shift their range further north for the foreseeable future. They may also decide not to travel south at all if waters stay warm enough. Becoming resident, has been witnessed in individuals in this species in the past near powerplants due to the way they kept water warm, so this species becoming resident with increased ocean temperatures is entirely possible.

References

* * {{Taxonbar, from=Q28165636 Scombridae Fish described in 1858