how to tuna?

Tuna aren’t a singular fish but a diverse group of oceanic species belonging to the tribe Thunnini, a division within the mackerel family Scombridae. This tribe encompasses approximately 15 distinct species, showcasing a remarkable range in size, from the diminutive bullet tuna to the colossal Atlantic bluefin

Consider the extremes: the bullet tuna Auxis rochei reaches a modest maximum length around 50 cm and a weight of about 1.8 kg. In stark contrast, the magnificent Atlantic bluefin tuna Thunnus thynnus boasts a significantly extended lifespan, with some individuals thriving for 35 to 50 years or even longer.

Recent assessments paint a mixed picture of their populations. A March 2025 report by the International Seafood Sustainability Foundation (ISSF) evaluated 23 global stocks of seven key commercial tuna species—albacore, bigeye, bluefin, skipjack, and yellowfin. Encouragingly, 65% of these stocks were deemed to be in a healthy state. However, the report also highlighted that 9% are currently overfished, and another 26% fall into an intermediate zone, requiring careful monitoring

Beyond their ecological status, tuna possess fascinating biological traits. They are exceptional swimmers, with some species capable of astonishing bursts of speed reaching up to 70 km/h around 43 mph. This agility is facilitated by their streamlined physique, powerful caudal fins, and the ability to retract their other fins, minimizing drag

Intriguingly, tuna are among the few fish that exhibit endothermy, a form of warm-bloodedness. Unlike most of their cold-blooded counterparts, they can maintain a body temperature higher than the surrounding water. This physiological advantage enhances their muscle efficiency, enabling sustained high-speed swimming for long-distance migrations and hunting expeditions into cooler waters

Fish with swim bladders for buoyancy: Tuna lack a swim bladder and rely on constant movement and specialized fins for buoyancy. Many bony fish possess a swim bladder to control their depth with less energy expenditure

Furthermore, their very survival is linked to constant motion. Tuna are obligate ram ventilators; they must continuously swim with their mouths open to ensure a constant flow of oxygen-rich water over their gills. Ceasing movement would lead to suffocation