Katsuwonus pelamis

• Conservation Status
• Taxonomy
• Physical Description
• Distribution
• Habitat
• Diet
• Reproduction
• Similar Species
• Bibliography
• More Info
• Notes
• Keep Exploring

Overview:

Family: Mackerels, tunas, bonitos; Found in offshore waters; larvae restricted to waters with surface temperatures of 15¦C to 30¦C (Ref. 6390). Exhibit a strong tendency to school in surface waters with birds, drifting objects, sharks, whales and may show a characteristic behavior like jumping, feeding, foaming, etc. Feed on fishes, crustaceans, cephalopods and mollusks; cannibalism is common. Preyed upon by large pelagic fishes (Ref. 6885). Also taken by trolling on light tackle using plugs, spoons, feathers, or strip bait (Ref. 9684). Marketed fresh, frozen or canned (Ref. 9340); also dried-salted and smoked (Ref. 9987). Spawns throughout the year in the tropics, eggs released in several portions (Ref. 35388).

Conservation Status

Status

Populations of skipjack tuna in the Atlantic Ocean have declined in recent years while populations in the Pacific Ocean appear to be stable. In the U.S., the National Marine Fisheries Service regulates tuna harvest and tuna imports for compliance with international conservation requirements.

Taxonomy

Unambiguous Synonyms:

1. Euthynnus pelamis (Linnaeus, 1758)
2. Euthynnus pelamys (Linnaeus, 1758)
3. Gymnosarda pelamis (Linnaeus, 1758)
4. Gymnosarda pelamys (Linnaeus, 1758)
5. Katsowonus pelamis (Linnaeus, 1758)
6. Katsuwinus pelamis (Linnaeus, 1758)
7. Katsuwonnus pelamis (Linnaeus, 1758)
8. Katsuwonus pelamys (Linnaeus, 1758)
9. Orcynus pelamis (Linnaeus, 1758)
10. Orcynus pelamys (Linnaeus, 1758)
11. Scomber pelamides Lacepède, 1801
12. Scomber pelamis Linnaeus, 1758
13. Scomber pelamys Linnaeus, 1758
14. Thinnus pelamis (Linnaeus, 1758)
15. Thynnus pelamis (Linnaeus, 1758)
16. Thynnus pelamys (Linnaeus, 1758)
17. Thynnus vagans Lesson, 1829

Notes:

Name Status: Accepted Name. Latest taxonomic scrutiny: Group expert : Collette B.B., Data last modified by FishBase 17-Mar-1994

Physical Description

Family Scombridae:

Distribution: tropical and subtropical seas. Body elongate and fusiform, moderately compressed in some genera. Snout pointed, premaxilla beaklike, free from nasal bones which are separated by the ethmoid bone; mouth large; teeth in jaws strong, moderate, or weak; no true canines; palate and tongue may bear teeth. The 2 dorsal fins separate and depressible into grooves with 5-12 finlets behind second dorsal and anal fins; first dorsal fin with 9-27 rays, origin well behind the head. Pectoral fins high on body. Pelvic fins moderate or small with 6 fin rays, placed below the pectoral fins. Caudal fin deeply forked with supporting caudal rays completely covering hypural plate. At least 2 small keels on each side of caudal fin base, a larger keel in between on caudal peduncle in more advanced species. Lateral line simple. Vertebrae 31-66. Body covered with small to moderate scales or a scaly corselet developed (area behind head and around pectoral fins covered with large thick scales) and rest of body naked or covered with tiny scales. Gill membranes not united to isthmus. Thunnus and close relatives with a specialized vascular system for heat exchange; the evolution of this and related adaptations for endothermy are discussed in Brock et al. 1993, Science 260:210-214. Primarily swift, epipelagic predators; some species occur in coastal waters, others far from shore. Mackerels (Scomber and Rastrelliger) filter plankton with their long gill rakers. Spanish mackerels, bonitos and tunas feed on larger prey, including small fishes, crustaceans and squids. The main predators of smaller scombrids are other predacious fishes, particularly large tunas and billfises. Dioecious and most display little or no sexual dimorphism in structure or color pattern. Females of many species attain larger sizes than maels. Batch spawning of most species takes place in tropical and subtropical waters, frequently inshore. Eggs are pelagic and hatch into planktonic larvae. Among the most important of commercial and sport fishes. Thunninae=ISSCAAP 36; Scombrinae=ISSCAAP 37. Also Ref. 50681.

The family Scombridae belongs to the Class Actinopterygii (ray-finned fishes) and the Order Perciformes. It contains 15 genera and 51 species. It may be found in Marine and Brackish environments and is primarily Marine. Members of this family are not used in the aquarium trade. Reproductively, most members of this family are nonguarders. The main mode of swimming of adult fish in this family is thunniform. Compared with other fish, the activity level of this family tends to be very active. Members of this family have been dated back to the lower Eocene epoch of the Tertiary period. Etymology of this family name: Latin, scomber = mackerel. 1841

Species Katsuwonus pelamis:

Distinctive Features: Like other tunas, the skipjack tuna has a fusiform body shape. It has two dorsal fins: the first with spines, the second without. Following the second dorsal fin are 7 to 9 finlets with separate rays useful in reducing turbulence and maintaining directional control when swimming at high speeds. The anal fin placement begins under the second dorsal fin and is also followed by 7 or 8 finlets. The caudal peduncle has three sets of keels: a large one on the base of the peduncle inserted between two smaller pairs. Keels are ridges that also help the fish maintain its position in the water when moving swiftly. The mouth extends to the center of the eye. The swim bladder is absent. Skipjack have a special system for partially regulating their body temperature, known as counter current exchange. This allows them to conserve body temperature, making them partially "warm blooded."

Dentition: There is a single row of small, conical teeth in the mouth.

Color:

The body color above is dark blue or purple, while the belly and lower sides are silvery and have 4 to 6 dark but broken lines running the length of the body. These stripes along the belly distinguish this tuna from other scrombrids living in the same waters.

Size/Age/Growth:

The record maximum length is 43 inches (108 cm) fork length and the maximum weight is 76 pounds (34.5 kg). Skipjack tuna commonly grow to a length of 32 inches (80 cm), and a weight of 7-22 pounds (8 to 10 kg).

Images:

Distribution

Aquatic Regions

Cosmopolitan in tropical and warm-temperate waters. Not found in the eastern Mediterranean Sea^[1] and the Black Sea. Highly migratory species, Annex I of the 1982 Convention on the Law of the Sea^[2]. Skipjack tuna are distributed circumtropically. Additionally, they are present along the oceanic coast of Europe and throughout the North Sea, but are absent from the Mediterranean Sea and Black Seas.

Range and Population

Cosmopolitan in tropical and warm-temperate waters. Not found in the eastern Mediterranean Sea^[3] and the Black Sea. Highly migratory species, Annex I of the 1982 Convention on the Law of the Sea^[4].

Habitat

The skipjack tuna is an epipelagic fish, occurring in waters ranging in temperature from 58-86°F (14.7 to 30°C). While skipjacks remain at the surface during the day, they may descend to depths of 850 feet (260 m) at night. Skipjacks have a tendency to school, often under drifting objects or marine mammals. Skipjacks exhibit many types of schooling behavior, sometimes schooling with drifting objects, sharks, or whales. They may swim slowly in circular paths or travel in a single direction. These schools may consist only of skipjack, or other tuna species may be present. Skipjack often divide into schools based upon their size. This may be because the smaller fish cannot maintain the same top speeds of larger fish. Small fish may school while feeding, whereas larger fish (greater than 8 inches (20 cm)) tend to feed alone.

Biome

Saltwater. Pelagic.

Diet

Skipjack feed primarily upon fishes, crustaceans, and mollusks. Fishes that are preyed upon by the skipjack tuna include herrings, anchovies, and sardines. Cannibalism is common with this species as well. Their diet appears to be very broad and suggests an opportunistic method of feeding. The peaks of foraging appear to occur around dawn and dusk. This may be in response to the diurnal, vertical migrations of other organisms, or it may suggest that skipjack satiate their food drive mid-day. Additionally, since skipjack appear to rely on vision when feeding, night may not offer enough light for visual recognition of prey. Schools of skipjack are commonly found near convergences and upwellings. In such sites, distinct bodies of water, often of varying temperature, collide with one another. These areas are generally very productive and food is abundant. Other organisms that may compete with adult skipjack for food include the whale shark, yellowfin tuna, albacore, frigate tuna, dolphin fish, rainbow runner, and seabirds.

Reproduction

Skipjack are oviparous. In warm equatorial waters, skipjack spawn year-round while futher away from the equator, spawning season is limited to the warmer months. Sexual maturity may occur as small as 15 inches (40 cm) length, however most fish appear to mature at larger sizes. Larger females produce significantly more eggs than smaller females, with the average adult producing 80,000 to 2 million eggs per year. The eggs are approximately 0.94 mm in diameter, with a clear shell. The larvae hatch at a size of 3.0 mm. They have large heads and jaws, and lack body pigmentation. They can be distinguished from closely related larvae by their pigmented forebrains. Like Thunnus species, they also lack pigment in the caudal region.

Behavior

Predators:

Large predatory fishes such as sharks, yellowfin tunas, billfishes, and wahoo, as well as seabirds are all predators of the skipjack tuna. Cannibalism is also known to occur in this tuna.

Parasites:

A well-studied host, the skipjack tuna has 75 documented parasites. These parasites include digenea (flukes), didymozoidea (tissue flukes), monogenea (gillworms), cestoda (tapeworms), nematoda (roundworms), acanthocephala (spiny-headed worms), and copepods. The cookiecutter shark (Isistius brasiliensis) is also a parasite of the skipjack tuna.

Similar Species

Members of the genus Katsuwonus:

There are approximately 5 species and subspecies in this genus: K. palamis · K. pelamis (Arctic Bonito) · K. pelanis · K. pleamis · K. vagans

Bibliography

• Bearez, P. (1996). Lista de los peces marinos del Ecuador continental. Rev. Biol. Trop. 44(2):731-741.
• Bianchi, G. (1986). Fichas FAO de identifacao de espécies para propósitos comerciais. Guia de campo para as espécies comerciais marinhas e de águas salobras de Angola. Preparado com o apoio da NORAD e da FAO (FIRM) Programa Regular, FAO, Rome. 184 p.
• Bouhlel, M. (1988). Poissons de Djibouti. Placerville (California, USA): RDA International, Inc. 416 p.
• Bruce, J.R., J.S. Colman and N.S. Jones (1963). Marine fauna of the Isle of Man. Memoir No. 36. Liverpool University Press, Liverpool.
• Cervigón, F. (1994). Los peces marinos de Venezuela. Volume 3. Fundación Científica Los Roques, Caracas,Venezuela. 295 p.
• Claro, R. (1994). Características generales de la ictiofauna. p. 55-70. In R. Claro (ed.) Ecología de los peces marinos de Cuba. Instituto de Oceanología Academia de Ciencias de Cuba and Centro de Investigaciones de Quintana Roo.
• Claro, Rodolfo, and Lynne R. Parenti / Claro, Rodolfo, Kenyon C. Lindeman, and L. R. Parenti, eds. 2001. Chapter 2: The Marine Ichthyofauna of Cuba. Ecology of the Marine Fishes of Cuba. Smithsonian Institution Press. Washington, DC, USA. 21-57. ISBN: 1-56098-985-8.
• Collette, B.B. and C.E. Nauen (1983). FAO species catalogue. Vol. 2. Scombrids of the world. An annotated and illustrated catalogue of tunas, mackerels, bonitos and related species known to date. FAO Fish. Synop. 2(125). 137 p.
• Collette, Bruce B. / Collette, Bruce B., and Grace Klein-MacPhee, eds. 2002. Mackerels: Family Scombridae. Bigelow and Schroeder's Fishes of the Gulf of Maine, Third Edition. Smithsonian Institution Press. Washington, DC, USA. 516-536. ISBN: 1-56098-951-3.
• Collette, Bruce B., Carol Reeb, and Barbara A. Block / Barbara A. Block and E. Donald Stevens, eds. 2001. Systematics of the Tunas and Mackerels (Scombridae). Fish Physiology, vol. 19: Tuna: Physiology, Ecology, and Evolution. Academic Press. San Diego, California, USA. 1-33. ISBN: 0-12-350443-0.
• Collette, Bruce B., and Cornelia E. Nauen 1983. Scombrids of the World: An Annotated and Illustrated Catalogue of Tunas, Mackerels, Bonitos and Related Species Known to Date. FAO Fisheries Synopsis, no. 125, vol. 2. Food and Agriculture Organization of the United Nations. Rome, Italy. 137. ISBN: 92-5-101381-0.
• Cornic, A. (1987). Poissons de l'Ile Maurice. Editions de l'Océan Indien, Stanley Rose Hill, Ile Maurice. 335 p.
• Duong, T.T. (2001). Mot so loai ca thuong gap o bien Viet Nam (Viet Nam's Common Marine Fishes Catalogue). Ministry of Fisheries of Viet Nam - Fisheries Information Center of Viet Nam.
• Hart, J.L. (1973). Pacific fishes of Canada. Fish. Res. Board Can. Bull. 180:1-740.
• Japan International Cooperation Agency (1987). The fisheries resources survey in Fiji and Tuvalu. Figures and tables. Japan International Cooperation Agency, April 1987.
• Kailola, P.J. (1991). The fishes of Papua New Guinea: a revised and annotated checklist. Vol. III. Gobiidae to Molidae. Research Bulletin No. 41, Research Section, Dept. of Fisheries and Marine Resources, Papua New Guinea. 153 p.
• Kailola, P.J., M.J. Williams, P.C. Stewart, R.E. Reichelt, A. McNee and C. Grieve (1993). Australian fisheries resources. Bureau of Resource Sciences, Canberra, Australia. 422 p.
• Kapoor, D., R. Dayal and A.G. Ponniah (2002). Fish biodiversity of India. National Bureau of Fish Genetic Resources Lucknow, India.775 p.
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• Maigret, J. and B. Ly (1986). Les poissons de mer de Mauritanie. Science Nat., Compiègne. 213 p.
• Marceta, B. (1999). Check-list of the fishes of the Gulf of Trieste (North Adriatic Sea) In prep. Provided on spreadsheet to FishBase (19 Jan 1999)
• Masuda, H., K. Amaoka, C. Araga, T. Uyeno and T. Yoshino (1984). The fishes of the Japanese Archipelago. Vol. 1 (text). Tokai University Press, Tokyo, Japan. 437 p. (text), 370 pls.
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Notes

Contributors:

• Bisby, F.A., Y.R. Roskov, M.A. Ruggiero, T.M. Orrell, L.E. Paglinawan, P.W. Brewer, N. Bailly, J. van Hertum, eds (2007). Species 2000 & ITIS Catalogue of Life: 2007 Annual Checklist. Species 2000: Reading, U.K.
• Brands, S.J. (comp.) 1989-2006. Systema Naturae 2000. The Taxonomicon. Universal Taxonomic Services, Amsterdam, The Netherlands. Accessed April 20, 2007.
• FishBase 2006.
• Global Biodiversity Information Facility. Accessed February 09, 2007. http://www.gbif.org Mediated distribution data from provider.

Data Sources:

Accessed through GBIF Data Portal November 14, 2007:

• Bernice Pauahi Bishop Museum, Bishop Museum Natural History Specimen Data
• Institute of Marine and Coastal Sciences, Rutgers University, Bishop Museum Data
• Institute of Marine and Coastal Sciences, Rutgers University, Bureau of Rural Sciences National commercial fisheries half-degree data set 2000-2002
• Institute of Marine and Coastal Sciences, Rutgers University, CSIRO Marine Data Warehouse
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, Marine and Coastal Management - Linefish Dataset
• Institute of Marine and Coastal Sciences, Rutgers University, iziko South African Museum - Fish Collection
• Museum of Comparative Zoology, Harvard University, MCZ Fish Collection
• OZCAM
• Provider, Online Zoological Collections of Australian Museums
• Royal Ontario Museum, Fish specimens
• UNIBIO, IBUNAM, CNPE/Coleccion Nacional de Peces

Identifiers:

• Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 172401
• Fishbase Species ID: 107
• Global Biodiversity Information Facility Taxonkey: 13535105
• Natural Heritage Network Species Identifier: AFCS309010
• Zipcode Zoo Species Identifier: 114199

Footnotes:

1. Blackburn, M. and D.L. Serventy (1981). Observations on distribution and life history of skipjack tuna, Katsuwonus pelamis, in Australian waters. Fish. Bull. 79:85-94.
2. FAO Fisheries Department (1994). World review of highly migratory species and straddling stocks. FAO Fish. Tech. Pap. No. 337. Rome, FAO. 70 p.
3. Blackburn, M. and D.L. Serventy (1981). Observations on distribution and life history of skipjack tuna, Katsuwonus pelamis, in Australian waters. Fish. Bull. 79:85-94.
4. FAO Fisheries Department (1994). World review of highly migratory species and straddling stocks. FAO Fish. Tech. Pap. No. 337. Rome, FAO. 70 p.