In the North Pacific coast the best time is usually between August and October, but it can be fished throughout the year. Yellowfin tuna is a favorite of fishermen. In the Central Pacific coast it can be found every month of the year, especially from June to September. In the Southern zone its best season coincides with Marlin and sailfish, but it can appear at other times of the year.
It reaches the maximum size of 94 inches, but it is common to find it when they approach 59 inches with weights of 388.89 pounds.
It can be found to depths of 1500 feet, although it is more frequent around 330 feet. It is a highly migratory species.
It has a strong tendency to form concentrations, more by size than by species, that usually occur in waters near the surface. The schools can be integrated by one or several species, even Costa Rica are observed along with dolphins or floating objects and debris.
It feeds on school fish, mainly molluscs and crustaceans.
General characteristics of Yellowfin Tuna
This tuna is quickly identified by presenting a dorsal, pectoral and long back fin, the dorsal fins are barely separated by a small space, the first one has 11 to 14 spines and the concave, second dorsal and back margin are similar, with the distal profile also concave and both followed by 7 to 10 pinions.
Dark blue metallic back, turning yellow to silver on the sides and belly, can ventrally have about 20 white lines, “broken”, almost vertical. Dorsal and rear fins, including pinions, bright yellow, pinules with a narrow black border.
Reproduction of Yellowfin Tuna
Fish larger than 120 cm are sexually mature and their age corresponds to about 24-36 months, but varies by region. They reproduce throughout the year in the central areas of their distribution. The spawning period is most intense when the temperature rises in the northern and southern hemispheres, respectively. In the Atlantic Ocean two breeding groups were detected: one that spawns between the months of May and August in the Gulf of Mexico and another that does so from July to November in the Caribbean Sea.
In Costa Rican waters, spawns twice a year, releasing several million eggs that, like the larvae, spend a short period as part of the pelagic communities. According to her size, a female releases 5 to 60 million eggs a year6. Eggs (like larvae) are pelagic, spherical, transparent and floating.
Method to catch Yellowfin Tuna
Its catch in sport fishing is by trolling using Bonito as bait but different lures are also used.
Location of Yellowfin Tuna in Costa Rica
It is found throughout the Pacific coast of Costa Rica and also on the Caribbean coast. The area of Tamarindo, Guanacaste is a favorite for many.