The common confusion between “Bonita” and “Tuna” arises frequently, yet these are distinct species, even though they share a broader family classification. While both are prized in fisheries and cuisine, their biological classifications, physical appearances, and culinary applications reveal clear differences.
Taxonomic Relationship
Bonita and Tuna both belong to the Scombridae family, which also includes mackerels. This familial connection means they share some evolutionary history, but they diverge at the genus level. Bonitas are classified under the genus Sarda, encompassing species like the Atlantic bonito (Sarda sarda) and the Pacific bonito (Sarda chiliensis).
Conversely, “true tunas” belong primarily to the genus Thunnus, which includes well-known species such as Bluefin (Thunnus thynnus), Yellowfin (Thunnus albacares), and Albacore (Thunnus alalunga). Other species like Skipjack tuna (Katsuwonus pelamis) are also considered tuna, belonging to different genera within the broader Thunnini tribe.
Distinguishing Characteristics
Observable physical attributes offer clear ways to differentiate Bonita from Tuna. Bonitas generally exhibit a more elongated and slender body shape compared to the more robust, torpedo-shaped bodies characteristic of many tuna species. Tuna, particularly larger species like Bluefin, are built for speed and endurance with sleek, streamlined forms.
A prominent visual cue is their coloration and stripe patterns. Bonitas typically display distinct diagonal or slanted dark stripes on their backs, extending towards their silvery bellies. In contrast, tunas often have more uniform coloration, generally dark metallic blue or black on top and silvery below, lacking the prominent diagonal stripes of Bonita. Size is another differentiating factor; Bonitas are generally smaller, typically reaching lengths of about 75 cm (30 inches) and weights up to around 12-15 kilograms. Many tuna species can grow significantly larger, with some Bluefin tuna exceeding 4 meters (14 feet) in length and weighing over 800 kilograms. Their fins also show differences: some Bonita species have notably long pectoral fins, while tunas are characterized by retractable fins that fold into grooves, along with small finlets behind their dorsal and anal fins.
Culinary Aspects
The biological differences between Bonita and Tuna translate into distinct culinary profiles. Tuna, especially Bluefin, Yellowfin, and Bigeye, is prized for its rich, often fatty, and relatively mild-flavored meat, which can range in color from light pink to deep red. This higher fat content and buttery texture make tuna a preferred choice for raw preparations like sushi and sashimi, as well as for searing into steaks. Overcooking tuna can result in a dry, grainy texture, so it is often prepared rare to medium-rare.
Bonita meat, on the other hand, typically has a stronger, more pronounced, and often described as “fishier” taste compared to tuna. Its flesh is generally darker and has a firmer, sometimes flakier, texture with moderate oil content. Due to its more robust flavor, Bonita is frequently used in preparations where a stronger fish taste is desired, such as smoking, canning, or in specific regional dishes. While some find its flavor too intense for raw consumption, others appreciate its richness in cooked applications like stews or grilled dishes.