Language:  GlossaryImagesHelp
 
Home: USES: Fisheries and Aquaculture: Fishery Resources: Capture Fisheries Resources: Biological characteristics of tunas and tuna-like species
Advanced Search | an expanded view of Topics and Knowledge in the Atlas
 Login for Members
 

 Username
 
 Password
 

 

Forgotten your Password?

 

Not a Member? Join Now

 Getting started
 
Navigate the Atlas:
 Related Knowledge (0)
 Topic Overview
 ID# : figis16082
 Visits: 0
 Added: 23-Mar-2007
 Updated: 23-Mar-2007
  E-Mail Topic link
 Editors
 Tina Farmer
 Fabio Carocci
 
 
 
 
Biological characteristics of tunas and tuna-like species
See source @ FAO Fisheries and Aquaculture ...
Text-only     Printer-friendly version             
Tuna and tuna-like species are very important economically and a significant source of food, with the so-called principal market tuna species the most significant in terms of catch weight and trade. These pages are a collection of Fact Sheets providing detailed information on tuna and tuna-like species.

Taxonomic Classification
[ Family: Scombridae ] :  Scombrids

[ Family: Istiophoridae  Family: Xiphiidae ] :  Billfishes
Upper systematics of tunas and tuna-like species
Scombrids and billfishes belong to the suborder of the Scombroidei which position is shown below:
   Phylum Chordata
   Subphylum Vertebrata
   Superclass Gnathostomata
   Class Osteichthyes
   Subclass Actinopterygii
   Infraclass Teleostei
   Superorder Acanthopterygii
   Order Perciformes
   Suborder Scombroidei

 
See more on Scombrids...

See more on Billfishes...
 
See more on "tuna common names"...

Fossil records
The first fossil records of Scombridae are dated from the beginning of the Eocene epoch (60-40 million years ago) during the Tertiary period. As for the Istiophoridae, the oldest fossils are dated from the upper Cretaceous epoch (70-90 million years ago) during the Secondary period. For the Xiphiidae, the oldest fossil records are dated from the Paleocene epoch of the lower Tertiary period, i.e. 57-65 million years ago (Berg, 1958).

Biological characteristics

Diagnostic Features

Morphology

Morphology of larvae

It is often difficult or impossible to identify larvae and, in some cases, early juveniles by anatomical characteristics or colour patterns. Biochemical or genetic methods can be used to distinguished the larvae of the various species (Elliott and Ward, 1995).

Morphology of juveniles and adults

Characteristics common to both scombrids and billfishes

Both scombrids and billfishes have two distinct dorsal fins, generally separated, the first one supported by spines and the second only by soft rays. The pelvic fins are inserted below the base of the pectoral fins. The caudal fin is deeply notched.

All scombrids and billfishes except swordfish have a pair of caudal keels on the middle of the caudal peduncle at the base of the caudal fin. The swordfish has only a large median caudal keel. The more advanced members of the Scombridae family also have a large median keel anterior to the pair of caudal keels. The bodies of all the Scombroidei are robust, elongate and streamlined. The first dorsal and first anal fins of all scombrids and billfishes, except swordfish, can fold down into grooves and the pectoral and pelvic fins into depressions when the fish is swimming rapidly.

The scombrids and billfishes, all have four gill arches on each side. The gill filaments are ossified as "Gill rays".

See more on Scombrids...
 
See more on Billfishes...

Geographical Distribution

Tropical and temperate tunas

Because of different distributions due to their specific thermal tolerances and because of exploitation by different fisheries, a distinction is made between tropical and temperate tunas. Tropical tunas are found in waters with temperatures greater than 18° C (although they can dive in colder waters) whereas temperate tuna are found in waters as cold as 10°C, but can also be found in tropical waters (Brill, 1994).
   Tropical tunas: skipjack and yellowfin
   Intermediate tunas: bigeye
   Temperate tunas: albacore, Pacific bluefin, Atlantic bluefin and southern bluefin

Tropical and temperate tunas
Tropical tunas Tropical tunas  Temperate tunas Temperate tunas

Scombrids

Tunas prefer oceanic waters, and 3 of the 8 species of Thunnus are found worldwide except in the Arctic Ocean. Bonitos and little tunas ( Euthynnus spp.) are primarily coastal fishes, but the distribution of individual species is often widespread. The frigate and bullet tunas ( Auxis spp.) are probably both oceanic and coastal (Olson and Boggs, 1986). The slender tuna and the butterfly kingfish have circum-global distributions in the Southern Ocean. Most mackerels and seerfishes have restricted ranges of distribution. Exceptions are the Spanish mackerel and the wahoo which are found worldwide.

Oceanic and neritic tunas

Oceanic tunas Oceanic tunas  Neritic tunas Neritic tunas

Billfishes

Billfishes are widely distributed, at least, throughout the oceans in which they occur. The exception are the Mediterranean spearfish, which occurs only in the Mediterranean Sea, and perhaps the roundscale spearfish, which occur in the northeastern Atlantic Ocean around the Canary and Madeira Islands and in the western Mediterranean Sea. However, only the swordfish is cosmopolitan. All other Istiophoridae are being confined to the Atlantic Ocean or to the Indian and Pacific Oceans.

Occurrence of the tuna, bonito and billfish species in the different oceans
Common names Scientific name Areas of occurrence
   Tunas and bonitos 
Skipjack  Katsuwonus pelamis  worldwide 
Yellowfin tuna  Thunnus albacares  worldwide 
Bigeye tuna  Thunnus obesus  worldwide 
Albacore tuna  Thunnus alalunga  worldwide 
Atlantic bluefin tuna  Thunnus thynnus  Atlantic Ocean 
Pacific bluefin tuna  Thunnus orientalis  Pacific Ocean 
Southern bluefin tuna  Thunnus maccoyii  southern parts of Atlantic, Indian and Pacific Ocean 
Longtail tuna  Thunnus tonggol  Indian Ocean, western Pacific Ocean 
Blackfin tuna  Thunnus atlanticus  western Atlantic Ocean 
Kawakawa  Euthynnus affinis  Indian, western and central Pacific Oceans 
Black skipjack  Euthynnus lineatus  eastern Pacific Ocean 
Little tunny  Euthynnus alleteratus  Atlantic Ocean 
Bullet tuna  Auxis rochei  worldwide 
Frigate tuna  Auxis thazard  Indian and Pacific Oceans 
Slender tuna  Allothunnus fallai  Southern Ocean 
   Billfishes 
Swordfish  Xiphias gladius  worldwide 
Atlantic sailfish  Istiophorus albicans  Atlantic Ocean 
Indo-Pacific sailfish  Istiophorus platypterus  Indian and Pacific Oceans 
Black marlin  Makaira indica  Indian and Pacific Oceans 
Indo-Pacific blue marlin  Makaira mazara  Indian and Pacific Oceans 
Atlantic blue marlin  Makaira nigricans  Atlantic Ocean 
Atlantic white marlin  Tetrapterus albidus  Indian and Pacific Oceans 
Striped marlin  Tetrapterus audax  Indian and Pacific Oceans 

Habitat and Biology

Ecological niche

Tunas are pelagic marine fish, spending their entire lives relatively near the surface of tropical, subtropical and temperate oceans and seas. Scombrids and billfishes live primarily in the water layers above the thermocline, but are able to dive to depth of several hundred meters (see the Vertical distribution section). Tuna species attaining only small sizes and juveniles of those attaining large sizes are encountered in epipelagic waters (from the surface to the thermocline) whereas large tunas tend to be mesopelagic and are found also in deeper and cooler waters.
   Epipelagic tunas: skipjack and bonitos
   Mesopelagic tunas (adults): albacore, bigeye and bluefin
   Tunas that are found at both depth ranges: yellowfin

Some tunas are found in both offshore and coastal waters and others entirely, or almost entirely, in coastal waters.
   Mid-ocean species: yellowfin and bigeye
   Coastal species: tonggol
   Species found in both waters: skipjack, albacore, Pacific bluefin, Atlantic bluefin and southern bluefin

Seerfishes are generally restricted to coastal waters and enter estuaries to feed. One species, the Chinese seerfish moves long distances in freshwater up the Mekong River in China.

Tuna and their environment

Important environmental parameters for tuna are the sea surface temperature, the quantity of dissolved oxygen in the water and the salinity. Lower thermal boundaries vary between 10°C for temperate tunas and 18°C for tropical tunas (see above; Brill, 1994). The minimum oxygen requirement is estimated between 2 to 2.7 ml/l for principal market tuna species except for bigeye tuna which can tolerate oxygen concentrations as low as 0.6 ml/l (Sharp, 1978 ; Lowe, 2000). Most tunas tend to concentrate along thermal discontinuities such as oceanic fronts (Sund, 1981).

Vertical distribution

The vertical distribution of most species of tunas is influenced by the thermal and oxygen structure of the water column. Tuna species attaining only small sizes and juveniles of those attaining large sizes tend to live near the surface, whereas adults of large species are found in deeper waters. The use of deep longlines showed that bigeye can be found at depths as great as 300 m (Suzuki et al., 1977). Albacore are also caught under FADs at depths to about 200 m (Bard et al., 1998). Acoustic telemetry has shown that billfishes are found near to the surface during the day, descending more frequently to greater depths at night (Block et al., 1992a). This is in contrast to the large daily vertical movements of the swordfish, which descends to depths as great as 600 m during the day (Carey and Robison, 1981).

Schooling behavior

Tunas use schooling to their advantage when they forage. Some tunas form parabolic-shaped schools to encircle their prey. Most tunas school according to size. Juveniles of tunas attaining large sizes are, therefore, often associated with tunas attaining only small sizes, such as skipjack or bonito. Schools of large adults consist of a few scattered individuals. Schooling offers protection for juvenile tunas by confusing predators and reducing the likelihood that any single fish will become a victim to a predator. Atlantic bluefin tuna can form giant schools spread over several nautical miles when migrating into the Mediterranean Sea to spawn during the summer. As is the case with the other fishes, the structure of tuna schools is maintained by the lateral line.

Migration and other movements

All tunas and tuna-like fishes move constantly to search for food and to keep water passing over their gills. Migrations are seasonal movements, often over long distances, for the purpose of feeding or reproduction. Temperate tunas, i.e. albacore, Atlantic bluefin, Pacific bluefin, and southern bluefin migrate long distances between temperate waters, where they feed, and tropical waters, where they spawn without moving among different oceans. Southern bluefin tuna also migrates among the Atlantic, Indian and Pacific Oceans. The spawning of the three species of bluefin is restricted to relative small areas of tropical waters. Tropical tunas, i.e. skipjack and yellowfin, are less migratory in terms of long-distance directional movements, although several tagged yellowfin released in the western Atlantic have been recaptured in the eastern Atlantic. Bigeye have some of the characteristics of both temperate and tropical tunas. They apparently do not make trans-oceanic migrations, but like the temperate tunas, they migrate back and forth between feeding grounds in temperate waters and their spawning grounds in tropical waters. When they are not making directional migration, tunas move nearly all the time in search of areas where the food is most abundant. Fishermen are sometimes able to predict on the basis of oceanic conditions where the fish are likely appear and then, they can transfer their operations to those areas. Little is known of the movements of billfishes, but apparently, they make seasonal migrations between temperate waters, where they feed, and tropical waters, where they spawn.

Swimming

Tunas are excellent swimmers, and their bodies are designed for high performance at both sustainable and burst swimming speeds (Dickson, 1995). Tunas must swim constantly to satisfy their oxygen requirements and consequently stay alive. The direction of movements of some species, such as skipjack, seem to be dictated solely by the availability of food. The movement of other species, such as the three species of bluefin, seem to be influenced by both the distribution of food and the need to return to their ancestral spawning grounds at the proper time. Tunas can move up to 15 km per night in order to forage on organisms that swim upward from deeper waters at that time.
See more on Scombrids...

Long-range swimming

The net distances travelled by tunas and billfishes (shortest distances between the locations of release and recapture) exceed those of any other fish, as shown by the following records obtained from tagging studies (from Joseph et al., 1988):
   10,790 km for a Pacific bluefin tuna (from southeast of Japan to off Baja California)
   10,680 km for a black marlin (from off Baja California to Norfolk Island in the South Pacific Ocean)
   9,500 km for a skipjack tuna (from off Baja California to the Marshall Islands)
   8,500 km for an albacore tuna (from off California to off Japan)
   7,700 km for an Atlantic bluefin tuna (accross the Atlantic Ocean)

In addition, net movements of more than 5,000 km have been recorded for yellowfin tuna, bigeye tuna, blue marlin, striped marlin and sailfish.

Short-range, fast swimming

Scombrids and billfishes are adapted to fast swimming. The champions are, of course, the most highly evolved scombrids, the bonitos (Sardini) and the tuna (Thunnini) and the billfishes.
They are able to exhibit startling bursts of speed, often exceeding one body length per second. The record (for all bony fishes) belongs to the sailfish ( Istiophorus spp.), which has been clocked at over 110 km/h.


Estimated maximun swimming speed of some tunas and billfishes
Species Sustained in m/s SL/s Burst in m/s SL/s
   Scombrids 
Thunnus albacares(1)  0.64  1.31  20.46  31
Thunnus obesus (1)  0.6  1.3  -  -
Thunnus thynnus (1)  3.49  1.64  -  -
Katsuwonus pelamis (1)  0.84  2.15  9.41  19.6
Euthynnus affinis (1)  0.76  2.11  5  10
Auxis rochei (1)  0.68  2.19  -  -
Sarda chiliensis (1)  0.88  1.54  3.70  6.49
Sarda sarda (1)  0.35  2.18  1.2  8.58
Acanthocybium solandri (1)  0.4  0.32  21.23  19.3
Scomber japonicus (1)  0.92  2.7  2.25  8.35
Scomber scombrus (2)  0.98  3.27   5.4   18
   Billfishes 
Tetrapterus audax (3)  1.8  -  -  - 
Makaira indica (3)  -  -  36.1  - 
Makaira nigricans (3)  1  -  2.25  - 
Xiphias gladius (2)  -  -  24.86  11.3 

References
(1): Magnuson (1978)
(2): Wardle and He (1988)
(3): Block et al. (1992b)

Physiological aspects of swimming

In order to swim at high speeds for long periods, tunas are capable of taking in and utilizing large amounts of oxygen.

In contrast to other fishes that contract their jaws and opercular muscles to pump water over their gills, tunas and billfishes (and some species of sharks) ram ventilate, that is they swim through the water with their mouths open, which forces water over their gills. This is an efficient way to get a large amount of water flowing through the gills at a low energetic cost, but it has an important drawback: tunas cannot stop swimming, or they will suffocate! They must swim at a speed of at least 0.65 m/s to provide sufficient flow of water over thier gills.

The amount of gill surface of tunas is up to 30 times those of other fish, and for some tunas the absorptive surface approaches those of the lungs of mammals of comparable weight (Joseph et al., 1988). This large surface enables the tunas to extract about half of the oxygen present in the water flowing over their gills.

To transfer oxygen from the gills to the other tissues, tunas have hearts that are about 10 times the size, relative to the weight of the entire body, of those of other fish. The blood pressure of tunas is about three times those of other fishes, and their hearts pump blood at a rate about three times those of other fish. The blood of tuna has a hematocrit of 40%, a value usually associated with diving mammals.

Scombrids and billfishes, like most fish, have two types of muscle, white and red. The white muscles function during short bursts of activity, while the red muscles, which have a relatively large mass, allow the fish to swim at high speeds (up to 45 km/h) for long periods without fatigue, as demonstrated by tagging studies with conventional and sonic tags (Joseph et al., 1988 ; Bushnell and Holland, 1997).

The proportion of red muscle is much greater for tunas than for other fish (Dickson, 1995) and their white muscles are capable of working in both aerobic and anaerobic conditions. Therefore, the increase in swimming speed can be portrayed as follows :


  sustained speed  high speed   burst speed  
red muscle in action  yes     
white muscle in action 
   aerobic condition yes  yes   
   anaerobic condition yes   yes  yes 

The red muscles are located deep within the body, and appear to be more important at the anterior part of the fish. They extend from the vertebral column to a lateral subcutaneous position. In contrast to other fishes, the proportion of red muscle does not seem to increase with the size of the tuna, probably because of greater muscle efficiency and labor sharing between red and white muscles, to which both endothermy and thermoregulation could contribute (Graham et al., 1983).

Muscle
Heart and white muscle aerobic capacities are significantly greater in tunas than in billfishes and other scombrids.

Recovery from intense activities

Furthermore, tunas and billfishes are capable of recovering more quickly than other fish after intense activities, such as that involved in capture of prey. For some tunas, the rates of removal of lactate from the blood and white muscle tissue approximate the rates measured in mammals, which allows the tuna to recover within two hours (Dickson, 1995).

Thermoregulation in tuna

As a consequence of swimming constantly to maintain hydrostatic equilibrium (Magnuson, 1973) and oxygenate the blood (Roberts,  1978), muscular metabolism continuously generates heat as a byproduct. Tunas get rid of this excess, but, on the other hand, the heat can be used by the tuna to enable them to forage in cold waters.

Metabolic mechanism for thermoregulation

Among all bony fish, the Thunnini are unique in their ability to regulate their body temperatures, due to a complex counter-current heat exhanger system, also called the rete mirabile (miraculous network) (Stevens and Neil, 1978). The only other fishes with this system are some sharks of the family Lamnidae (Collette, 1978).

The tuna maintain their body temperatures above that of the ambient water by passing arterial blood through vascular countercurrent heat exchangers. All species of tuna have a lateral rete, consisting of small arteries branching from the lateral subcutaneous arteries and small veins emptying into the lateral veins (Graham et al., 1983). In addition, many species of tuna also have a central rete within the vertebral haemal canal, consisting of arteries from the dorsal aorta and veins to the posterior cardinal veins (Stevens and Neil, 1978). The arterial blood is, then, warmed by the venous blood that flows through the red swimming muscles (Holland et al., 1992).

The rete mirabile retains between 70 and 99 % of the heat produced by the red muscle fibers, and provide a barrier between the red muscle and the environment (Graham et al., 1983). However, when excessive temperatures have been generated by heavy exercise, tunas appear to be able to control the efficiency of the heat exchangers by closing down some blood vessels of the rete mirabile, allowing heat to dissipate into the colder ambient water (Bushnell and Holland, 1997).

Measurements of body temperatures and ambient temperatures with histological analyses of the rete mirabile show that tunas as small as 207 mm in length can maintain their body temperatures more than 3°C above the ambient temperature, and thus can be considered to be endotherms (Graham et al., 1983). Tuna body temperatures are often 10°C greater than those of ambient water. The maximum temperature difference was recorded for an Atlantic bluefin tuna, for which the body temperature was 21.5°C greater than the surrounding water (Graham et al., 1983).

The thermoregulatory system cannot conserve heat indefinitely, and when a fish has been foraging in deep, cold water for an extended period, its body temperature decreases. When this happens, it can ascend to warmer water and disengage its thermoregulatory system to allow rapid warming of the tissues (Holland et al., 1992).

Behavioural mechanisms for thermoregulation

Combined with the physiological mechanisms, movements into cooler water will facilitate heat dissipation (Bushnell and Holland, 1997).

Advantages of thermoregulation

Thermoregulation allows the tunas to sustain high swimming speeds for long periods and to recover quickly after prolonged exertion (Carey et al., 1971), because most biochemical reactions proceed more rapidly at higher temperatures. Therefore, according to Bushnell and Holland, 1997, elevated body temperatures allow:
   red muscle to contract more quickly, approaching the contraction rate of white muscle and consequently, contributing to high-speed swimming resulting from white muscle contractions
   more rapid transfer of oxygen from blood to muscle cells
   more rapid recovery, by enhancing the breakdown of lactic acid

In addition, being "warm bodied" allows the tunas to have a good vision at significant depths by maintaining their brains and eyes at greater than ambient temperatures (Bushnell and Holland, 1997). It also allows the tuna to be more sensitive to thermal gradients (Sharp and Dizon, 1978).
Also, because of that, the tuna can forage beneath the thermocline, in deep water, without suffering radical decreases in their core temperature. For example, a bigeye tuna was observed to dive 250 meters in one minute, going from 24°C to 9°C water (Holland et al., 1992).

Trophic relations and growth

Growth stages

The following three stages can be distinguished:
   larvae (recently hatched individuals which are considerably different in appearance from juveniles or adults)
   juveniles (similar in appearance to adults, but sexually immature)
   adults (sexually mature fish)

Trophic position of larvae

Larvae of tunas and tuna-like fishes live in warm surface waters and feed primarily on the zooplankton including small crustaceans and larvae of crustaceans, fishes, molluscs and jelly-fish. Larvae of tunas and tuna-like species are preyed upon by zooplankton foragers, such as larger larvae and early juveniles of pelagic fishes. Cannibalism is, therefore, an important cause of mortality for tuna larvae.

Trophic position of juveniles and adults

Tunas and tuna-like fishes in the oceanic food web

Tunas and billfishes prey on fish, squid and crustaceans. The larger individuals (wahoo, bonitos, tunas and billfishes), which feed on pelagic fishes, are positioned at the top of the trophic web. The smaller individuals (juvenile tunas and billfishes, mackerels and seerfishes) prey on zooplankton (mainly crustaceans) and constitute part of the ration of large scombroids, sharks and cetaceans. Analyses of stomach contents of yellowfin and skipjack tuna indicate that they feed on small epipelagic fishes between 1 and 10 cm in length (Roger, 1994). Since these prey of yellowfin and skipjack feed directly on zooplankton (mainly copepods), it seems that the tunas are at the top of a short food web, which is probably very efficient from the point of view of energetics.
Position of tunas and tuna-like fishes in the food web
Food web
Position of tunas and tuna-like fishes in the food web

Food items

Tunas and billfishes are opportunistic feeders. At the species level, they do not have strong preferences for certain types of prey. However, on a regional scale and at a given time, a few species may represent almost all of the food of fish of a specific age group (Cayré et al., 1988). Tunas and billfishes prey on pelagic or epipelagic fishes (including small tunas), crustaceans and molluscs (squids). Coastal tunas feed on neritic and epipelagic prey (Olson and Boggs, 1986).

Foraging behavior of juveniles and adults

Tunas and billfishes are predators that locate their prey visually. To satisfy their food requirements tunas and billfishes have to swim long distances. Their type of locomotion is, therefore, particularly adapted to the search for prey in a large volume of water with the least expenditure of energy. However, they appear less effective than transient predators, such as esocids, in actually capturing the prey (Webb, 1984). To compensate for this, tunas tend to break up schools of prey, producing disorientation and straggling, and/or search for prey in schools (Webb, 1984; Partridge, 1982). Tunas can detect minute traces of scents of oils, proteins and amino-acids of the mucus layer produced by their prey. When prey is detected, some tunas show changes in their behavior consisting of a general increase of activity: increase in swimming speed, change in swimming pattern, jaw snapping and display of dark stripes on the flanks. Tropical tunas often dive down to or below the thermocline to feed (Holland et al., 1992). It is commonly believed that tunas feed during the day. However, sonic tracking experiments show that some tunas feed also at dusk, when mesopelagic micronecton migrate toward the surface (Bard et al., 1998).
Size

Common and maximum sizes of tunas and billfishes

Tunas (1)
Scientific name Common size (in cm) Maximum size (in cm) Maximum weigh t (in kg)
Auxis rochei  15-35  50  - 
Auxis thazard  25-40  58  - 
Euthynnus lineatus  30-65  70  9 
Euthynnus alleteratus  30-80  100  12 
Euthynnus affinis  30-60  100  13 
Katsuwonus pelamis  40-80  108  33 
Thunnus atlanticus  40-70  100  19 
Thunnus alalunga  40-100  127  40 
Thunnus tonggol  40-70  130  35 
Thunnus albacares  60-150  200  175 
Thunnus maccoyii  160-200  225  160 
Thunnus obesus  70-180  230  200 
Thunnus thynnus  80-200  300  650 


Bonitos (1)
Scientific name Common size (in cm) Maximum size (in cm) Maximum weight (in kg)
Cybiosarda elegans  35-45  50  5 
Sarda sarda  30-50  85  7.5 
other Sarda *  30-50  100  - 
Allothunnus fallai  65-95  96  10 
Orcynopsis unicolor  40-90  130  13 
Gymnosarda unicolor  65-150  200  131 

* Sarda australis, S. chiliensis, S. orientalis, S. sarda

Seerfishes and mackerels (1)
Scientific name Common size (in cm) Maximum size (in cm) Maximum weight (in kg)
Rastrelliger faughni  -  20  0.75 
Rastrelliger brachysoma  15-25  35  - 
Rastrelliger kanagurta  15-25  35  - 
Grammatorcynus spp.  -  60  3.5 
Scomber spp.  15-30  40-50  1 
Scomberomorus multiradius  -  35  0.5 
Scomberomorus concolor  -  75-80  - 
Scomberomorus guttatus  -  75-80  - 
Scomberomorus niphonius  -  100  4.5 
Scomberomorus cavalla  20-70  170  - 
Scomberomorus commerson  30-90  220  45 
Gasterochisma melampus  74-164  164  - 
Acanthocybium solandri  100-170  210  80 


Billfishes (2)
Scientific name Common size (in cm) Maximum size (in cm) Maximum weight (in kg)
Tetrapterus georgei  -  160 BL  21 
Tetrapterus pfluegeri  -  200 BL  45 
Tetrapterus angustirostris  -  200 TL  52 
Tetrapterus belone  -  240 BL  70 
Tetrapterus albidus  130-210 BL  280 TL  82 
Tetrapterus audax  140-280 BL  350 TL  200 
Istiophorus albicans  125-210 BL  315 TL  58 
Istiophorus platypterus  140-240 BL  340 TL  100 
Xiphias gladius  115-190 BL  445 TL  540 
Makaira nigricans  230-345 TL  375 TL  580 
Makaira indica  170-210 BL  448 TL  700 
Makaira mazara  200-300 BL  447 TL  900 

Notes for billfishes: BL = Body Length, TL = Total Length

References:
(1): Collette and Nauen (1983)
(2): Nakamura (1985)


International Game Fish Association (IGFA) records

Tunas and bonitos

Common name Record size (in cm) Record weight (in kg) Location and year of capture
Sarda chiliensis  -  6.3  off Baja California, 1980 
Euthynnus lineatus  -  11.8  off Baja California, 1991 
Euthynnus alleteratus  92.7  12.2  off Florida, 1976 
Katsuwonus pelamis  99  18.9  off Mauritius island, 1982 
Thunnus alalunga  123  40  off Canary Islands, 1972 
Acanthocybium solandri  -  72  off Baja California, 1996 
Thunnus albacares  208  176.4  west coast of Mexico, 1977 
Thunnus obesus  236  197.3  off Peru, 1957 
Thunnus thynnus  304  679  off Nova Scotia, 1979 


Seerfishes and mackerels

Common name Record size (in cm) Record weight (in kg) Location and year of capture
Scomber japonicus  -  1.9  off Baja California, 1986 


Swordfish and billfishes

Common name Record size (in cm) Record weight (in kg) Location and year of capture
Istiophorus albicans  -  61.4  off Nigeria, 1991 
Tetrapterus albidus  -  82.5  off Brazil, 1979 
Istiophorus platypterus  327.7  100.2  off Galapagos, 1947 
Tetrapterus audax  -  224.0  off New Zealand, 1986 
Xiphias gladius  445  536.1  off Chile, 1953 
Makaira mazara  -  624.1  off Hawaii, 1982 
Makaira nigricans  -  636.0  off Brazil, 1992 
Makaira indica  442  707.6  off Peru, 1953 

Source: IGFA (1995)

Growth rates

Most scombrids grow rapidly and reach their adult sizes in a few years. Average growth rates vary according to the species, the age and the location. In general, larger tunas grow to about 40 to 55 cm the first year, then the annual growth rate ranges between 20 to 30 cm per year decreasing with age. Tuna species attaining only small sizes grow to 20 to 35 cm in the first year and their annual length increments rapidly decrease to less than 10 cm. In the Atlantic and Indian Oceans, several studies have shown that yellowfin grow rapidly during the first year, slowing their growth during the next one or two years and then having again a fast growth before gradually slowing down as the maximum size is approached. Seerfishes and mackerels have also a fast growth during their first years of life. Sizes of 35 to 45 cm at age 1 year are common.

Billfishes can grow to more than 80 cm during their first year of life. After this very fast juvenile growth, adult growth rates are comparable to those of tunas.
 
See more on Scombrids...

Longevity

Longevities of tunas vary from a few years for the smaller tunas to 12 to 15 years for the larger tunas. The longevity record for tunas is about 20 years for the Atlantic bluefin tuna (Cort, 1990) and for the southern bluefin tuna. Longevities of 20 years have also been estimated for several species of billfishes.

Natural mortality

For larger tunas and billfishes, adult natural mortalities range from 0.2 to 0.6. Juvenile natural mortalities are higher. Little is known on natural mortalities of seerfishes and mackerels.

Reproduction of tunas and tuna-like fishes

Spawning

Spawning behavior

Tuna spawn in open water close to the surface. Eggs are released by females in several batches. For example, yellowfin tuna in the Pacific spawn nearly every day. However, for some species like bluefin, spawning is more seasonal.

Spawning areas and seasons

Tunas spawn in areas where the survival of their larvae is greatest. Most species of tunas spawn only in waters where the surface temperatures are greater than 24°C. Tropical tunas appear to spawn in equatorial areas all year around and at higher latitudes during the warm seasons. Albacore and bigeye appear to migrate annually from temperate feeding areas to tropical spawning areas. Bigeye larvae are less abundant than those of other tropical tunas, and are found mainly in equatorial waters in which the temperatures are greater than 28°C (Collette and Nauen, 1983). Atlantic bluefin, Pacific bluefin and southern bluefin tuna exhibit a homing behavior when they mature, and return to restricted areas in the Atlantic, Pacific and Indian Oceans to spawn. It is commonly accepted that there is a homing behavior, but to a lesser extent, in yellowfin in the Atlantic Ocean. Billfishes appear to spawn in warm tropical and subtropical waters.

Maturity and fecundity

The batch fecundities of most species of tunas range from 2 to 70 million eggs, the lowest fecundity being for albacore and the highest for skipjack tuna and other small-sized tunas. Known batch fecundities of mackerels range from 300 000 to 1 500 000 eggs. Little is known on fecundities of seerfishes. Fecundity of wahoo has been estimated to 6 million eggs. Very little information on reproductive biology of billfishes is available. Swordfish batch fecundity was estimated to 3.9 millions eggs in the Atlantic.

Maturity and fecundity parameters of the principal market species of tunas
Scientific name Size and age at maturity Annual batch fecundity
Katsuwonus pelamis  about 3 years and 42 to 45 cm   7 to 76 million eggs 
Thunnus alalunga  about 5 years and 90 cm   2 to 3 million eggs 
Thunnus albacares  about 3 years and 100 cm   4 to 60 million eggs 
Thunnus obesus   about 3 years and 100 cm   4 to 60 million eggs  
Thunnus thynnus  about 4 years and 105 to 120 cm  5 to 30 million eggs 

Sex ratio

It has been shown that for yellowfin, bigeye and albacore, the sex-ratio changes with the age of the fish with a predominance of males for the larger sizes. A predominance of females has also been observed for medium-sized Atlantic bluefin tuna. For skipjack, differences in the numbers of males and females have been observed locally. Predominance of females at older ages is observed for several species of billfishes.

Ackowledgment
Michel Goujon and Jacek Majkowski, who compiled the information contained in this presentation, are grateful to:
- Marcella Pesce* (consultant involved in the development of FIGIS) for restructuring and editing the information according to FIGIS requirements,
- Aureliano Gentile (consultant involved in the development of FIGIS) and Yves Jaques (Information Officer of FAO's Fishery Information, Data and Statistic Unit (FIDI)) for incorporating the restructured and edited information into FIGIS and
- Ignacio de Leiva (Fishery Resources Officer of FAO's Marine Resources Service (FIRM)) for his suggestions for improvements to the presentation.
*Presently, an expert in the information technology in FAO's Inland Water Resources and Aquaculture Service (FIRI).
Bibliography

Bard, F.X., E. Josse and P. Bach, 1998. Habitat, écophysiologie des thons. ICCAT symposium.

Beamish, F.W.H., 1978. Swimming capacity. pp 101-187. In: Fish Physiology, Vol. 7. W.S. Hoar and D.J. Randall (eds), Academic Press, New York.

Berg, L.S., 1958. System der rezenten und fossilen Fischartigen und Fische. VEB Verlag der Wissenschaften, Berlin.

Block, B.A., D.T. Booth and F.G. Carey, 1992a. Depth and temperature of the blue marlin, Makaira nigricans, observed by acoustic telemetry. Mar. Biol., 114: 175-183.

Block, B.A., D.T. Booth and F.G. Carey, 1992b. Direct measurement of swimming speeds and depth of blue marlin. J. Exp. Biol., 166: 267-284.

Brill, R., 1994. A review of temperature and oxygen tolerance studies of tunas pertinent to fisheries oceanography, movements models and stock assessments. Fish. Oceanogr., 3 (3): 204-216.

Bushnell, P.G. and K.N. Holland, 1997. Tunas. Virginia Mar. Res. Bull., 29 (1 & 2): 3-6.

Carey, F.G., J.M. Teal, J.W. Kanwisher, K.D. Lawson and J.S. Beckett, 1971. Warm bodied fish. Am. Zool., 11 (1): 137-145.

Carey, F.G. and B.H. Robison, 1981. Daily patterns in the activities of swordfish, Xiphias gladius, observed by acoustic telemetry. Fish. Bull. U.S., 79: 277-291.

Cayré, P., J.B. Amon Kothias, J.M. Stretta and T. Diouf, 1988. La biologie des thons. pp 167-183 in A. Fonteneau and J. Marcille (eds), Ressources, pêche et biologie des thonidés tropicaux de l'Atlantique centre-est, FAO Fish. Tech. Pap., 292, Rome: 391 p.

Collette, B.B., 1978. Adaptations and systematics of the mackerels and tunas. pp 7-39 in G.D. Sharp and A.D. Dizon (eds), The Physiological Ecology of Tunas, Academic Press, New-York: 485 p.

Collette, B.B. and C.E. Nauen, 1983. FAO Species catalogue, vol. 2. Scombrids of the worlds. An annotated and illustrated catalogue of tunas, mackerels, bonitos and related species known to date. FAO Fish. Synop., 125 (2), Rome: 137 p.

Cort, J.L., 1990. Biologío y peca del atún rojo, Thunnus thynnus (L.), del Mar Cantábrico. Inst. Español Ocean., Publ. Esp., 4: 272 p.

Dickson, K.A., 1995. Unique adaptations of the metabolic biochemistry of tunas and billfishes for life in the pelagic environment. Env. Biol. Fish., 42: 65-97.

Elliott and Ward, 1995Elliott, N.G. and R.D. Ward, 1995. Genetic relationships of eight species of Pacific tunas (Teleostei: Scombridae) inferred from allozyme analysis. Mar. Fresh. Res. 46 (7): 1021-1032.

Graham, J.B., F.J. Koehrn and K.A. Dickson, 1983. Distribution and relative proportions of red muscle in scombrid fishes: consequences of body size and relationships to locomotion and endothermy. Can. J. Zool., 61: 2087-2096.

Holland, K.N., R.W. Brill, R.K.C. Chang, J.R. Sibert and D.A. Fournier, 1992. Physiological and behavioural thermoregulation in bigeye tuna. Nature, 358: 410-412.

Joseph, J, W. Klawe and P. Murphy, 1988. Tuna and Billfish - fish without a country. 4th edition, Inter-American Tropical Tuna Commission (ed.), La Jolla, California: 69 p.

Klawe, W.L., 1976. Tuna as an English word for a scombrid fish. Inter-Am. Trop. Tuna Comm. (Unpubl. Manuscr.).

Klawe, W.L., 1977. What is a tuna? Marine Fisheries Review, 39 (11), paper 1268: 5 p.

Lowe, T.E., R.W. Brill, and K.L. Cousins, 2000. Blood oxygen-binding characteristics of bigeye tuna (Thunnus obesus), a high-energy-demand teleost that is tolerant of low ambient oxygen. Marine Biology, 136: 1087-1098.

Magnuson, J.J., 1973. Comparative study of adaptations for continuous swimming and hydrostatic equilibrium of scombroid and xiphoid fishes.Fish Bull., 71 (2):337-356.

Magnuson, J.J., 1978. Locomotion by scombrid fishes: hydrodynamics, morphology, and behavior. Fish Physiol., 7: 239-313.

Nakamura, I, 1985. FAO Species catalogue, vol. 5. Billfishes of the world. An annotated and illustrated catalogue of marlins, sailfishes, spearfishes and swordfishes known to date. FAO Fish. Synop., 125 (5), Rome: 65 p.

Olson, R.J. and H. Boggs, 1986. Apex predation by yellowfin tuna (Thunnus albacares): independent estimates from gastric evacuation and stomach contents, bioenergetics and cesium concentrations. Can. J. Fish. Aquat. Sci. 43 (9):1760-1775.

Partridge, B.L., 1982. The structure and function of fish schools. Scient. Amer., 247: 114-123.

Roger, C., 1994. The plankton of the tropical western Indian ocean as a biomass indirectly supporting surface tunas (yellowfin, Thunnus albacares and skipjack, Katsuwonus pelamis. Environ. Biol. Fish. 39 (2):161-172.

Roberts, J.L., 1978. Ram gill ventilation in fish. pp. 83-88 in : G.D. Sharp and A.D. Dizon (eds), The Physiological Ecology of Tunas, Academic Press, New-York: 485 p.

Sharp, G.D., 1978. Behavioural and physiological properties of tunas and their effects on vulnerability to fishing gears. pp 397-450 In G.D. Sharp and A.E. Dizon (eds), The physiological ecology of tunas, Academic Press, New York: 485 p.

Sharp, G.D. and A.D. Dizon, 1978. The Physiological Ecology of Tunas. Academic Press, New-York: 485 p.

Stevens, E.D. and W.H. Neill, 1978. Body temperature relations of tunas, especially skipjack. pp 315-359 in : Fish Physiology, vol VII (ed. W.S. Hoar and D.J. Randall), New York : Academic Press.

Sund, P.N., M. Blackburn and F. Williams, 1981. Tunas and their environment in the Pacific Ocean: a review. Oceanogr. Mar. Biol. Ann. Rev., 19: 443-512.

Suzuki, Z., Y. Warashina, M. Kishida, 1977. The comparison of catches by regular and deep longline gears in the Western and Central Equatorial Pacific. Bull. Far Seas Res. Lab., 15: 51-90.

Wardle, C.S. and P. He., 1988. Burst swimming speeds of mackerel, Scomber scombrus L. J. Fish Biol. 32 (3): 471-478.

Webb, P.W., 1984. Body form, locomotion and foraging in aquatic vertebrates. Amer. Zool., 24: 107-120.
 
 
 
 
979 Topics - 5229 Related Knowledge - 11257 Members - 47 Editors
freeMem:98,819,568 totMem:446,169,088 reqNum:1122058 openSessions:0 generationTime:2013/05/25 07:09:39