Family: Scombridae (Mackerels, tunas, bonitos),
subfamily: Scombrinae Order: Perciformes
Class: Actinopterygii Fish Base name: Yellowfin tuna
Max. size: 239 cm FL (male/unsexed);
max. published weight: 200.0 kg ;
max. reported age: 8 years
Environment: pelagic, oceanodromous, brackish, marine, depth range 1 – 250 m
Climate: tropical; 15 – 31°C; 45°N - 45°S, 180°W - 180°E
Thunnus albacares, a kind of tuna, The second dorsal fin and the anal fin are both bright yellow, so thus its common name as yellowfin tuna, and can be very long in mature specimens, as are the pectoral fins. It is found in open waters of tropical and subtropical seas worldwide. Yellowfin tuna are a popular sport fish in many parts of their range and are prized for their speed and strength when fought on rod and reel as well as for their table qualities.
Both physical and physiological
Tuna muscles have aerobic oxidation rates that are 3–5 times higher than in other teleosts and extremely high glycolytic capacity (150 mol g–1 lactate generated) due to enhanced concentration of glycolytic enzymes. Gill resistance in tuna is high and may be more than 50% of total peripheral resistance so that dorsal aortic pressure is similar to that in other active fishes such as salmon or trout. An O2 delivery/demand model predicts the maximum sustained swimming speed of small yellowfin and skipjack tuna is 5.6 BL s–1 and 3.5 BL sec–1, respectively. The surplus O2 delivery capacity at lower swimming speeds allows tuna to repay large oxygen debts while swimming at 2–2.5 BL s–1. Maximum oxygen consumption (7–9 × above the standard metabolic rate) at maximum exercise is provided by approximately 2 × increases in each of heart rate, stroke volume, and arterial-venous O2 content difference. The large surface area of the gills and thin blood-water barrier means that O2 utilization is high (30–50%) even when ram ventilation approaches 101 min–1kg–1. The heart is extremely large and generates peak blood pressures in the range of 70–100 mmHg at frequencies of 1–5 Hz. The blood O2 capacity approaches 16 ml dl–1 and a large Bohr coefficient (–0.83 to –1.17) ensures adequate loading and unloading of O2 from the well buffered blood (20.9 slykes).
(Source: International Union of Biological Societies symposium The biology of tunas and billfishes: an examination of life on the knife edge , organized by Richard W. Brill and Kim N. Holland.)
Because of its physical and physiological modifications to the oxygen transport system promote high metabolic performance of tuna, the marine collagen extracted and refined from the skin of Thunnus albacares has excellent thermo-stability compared to other collagen derived from fish. It is reported that the collagen from warm-water fishes, like Thunnus albacares, is more stable than the collagen from a cold-water fish like salmon.
The fish skin is highly refined and the collagen is extracted, therefore collagen from Thunnus albacares marine fish is of high quality.
Table : Thermal Stability of various fish species
Resistance to Temperature (Td)
Pacific saury fish