Mackerel Family Photos and Information – Scombridae
Skipjack Tuna, Katsumonus pelamis, a representative of the Mackerel or Scombridae Family.
The Mackerel or Scrombridae Family, known as macarelas in Mexico, includes bonitos, mackerels, and tunas, which are some of the most important food fishes and popular game fishes in the world. The family has 54 global species that have been placed in 15 genera that are found worldwide in tropical and temperate waters. Of those, 23 are found in Mexican oceanic waters, eight in the Atlantic, eight in the Pacific and 15 in both oceans. They have elongated robust fusiform bodies that are moderately compressed are built for speed. The body colorations are a metallic blue than transition to silvery ventrally. Some are the fastest fish in the ocean and can approach 47 mph (75 kmph) with strong endurance. Species range in length from 20 cm (7.9 inches) to 4.58 meters (15 feet). They have heads with pointed snouts and large mouths and the well-developed teeth vary by species. Their caudal fins are deeply forked and most have caudal fin bases with three keels with a larger one in the middle. They all have two separated dorsal fins and a series of five to 12 finlets behind the rear of the anal and dorsal fins. The first dorsal fins have nine to 27 rays and originate well behind the head. The pectoral fins are high on the body. The pelvic fins are modest to small in size with six fin rays and are found below the pectoral fins. The lateral lines are simple and the bodies are covered with small to moderate sized scales or they have a scaly corselet of large thick scales. Scombrids maintain a pelagic, nomadic existence, often with wide migratory patterns for feeding and reproduction and include transitions to cooler waters. Scombrids can be found as solitary individual or in ginormous mixed schools of similar sized of up to 5,000 individuals and can migrate up to 15 km (10 miles) per day. They occur in coastal waters, some only in oceanic waters, and some in both. Most are found near the surface, in water with temperatures between 10oC (50oF) and 18oC (64oF), with high oxygen content (2.0 to 2.7 ml per liter) and salinity, above the thermal incline. Tunas need to be in continual motion to generate an adequate amount of oxygen in their system to avoid them from suffocating. To help absorb oxygen from the water they have an extraordinary amount of gill surface. Many are found along the thermal discontinuities such as oceanic fronts. They only go into deeper waters in pursuit of prey. They remain in continuous motion requiring a continual source of oxygen for survival. They are opportunistic daytime visual predators of the open oceans. The smaller mackerels have long gill rakers and are filter plankton feeders. The bonitos, larger mackerels, and tuna feed on larger prey including crustaceans, small fishes, and squid. The tunas attack schools of prey fish trying to break up schools, producing disorientation and straggling. In turn they are preyed on by larger fishes including billfish and large tunas, sharks, seals, porpoises and sea birds. Humans are also major predators of scombrids. Many of the tunas are warm blooded that helps them maintain high speeds and endurance. The tunas have large hearts and blood volumes as-well-as high proportions of red muscle that allows for sustained swimming. They have very high metabolic rates and require a continual source of food. The sexes are normally very similar and cannot be differentiated visually, however the females may be larger than the males. Reproduction is oviparous with year round batch spawning with each female tuna releasing from 2 to 70 million eggs annual that quickly hatch into planktonic larvae that grow quickly. Fecundities of mackerel range from 300,000 to 1.5 million eggs per female per year. Fecundity in Wahoo is approximately 6 million eggs. Most scombrids grow rapidly reaching maturity in two to five years. Average growth rates vary according to the species. In general, the larger tunas grow to about 40 cm (16 inches) to 55 cm (22 inches) the first year and then the annual growth rates slow to 20 cm (8 inches) to 30 cm (12 inches) per year. The smaller Tuna species only attain 20 cm (8 inches) to 35 cm (14 inches) in the first year and their annual length increments rapidly decrease to less than 10 cm (4 inches). Tunas range in length from 50 cm (20 inches) to more than 3.0 meters (9 feet 9 inches) and from 1 kg (0.5 pounds) to 2 kg (2 pounds) to more than 600 kg (1,320 pounds) in weight. In contrast the bonitos and mackerels are of less than 1 meter in length. The mackerels and small tuna have life spans of a few years; the large tuna have live spans of twelve to fifteen years. Scombrids date to the lower Tertiary lower Eocene period, forty to sixty million years ago.
Most scombrids are important food, commercial, and sport fishes. Albacore, Atlantic Bluefin, Bigeye, Pacific Bluefin, Skipjack, Southern Bluefin and Yellowfin Tuna are some of the most important commercial fishes in the world and caught at the level of five to six million tons collected annually. In some parts of the world heavy commercial exploitation of open-ocean tunas has led to depletion of tuna populations. Much of the tuna catch is harvested for canning. Many of the world angling records for Scombrids have occurred in Mexican waters – these include the Albacore, Thunnus albacares (West Coast of the mainland), the Black Skipjack, Euthynnus lineatus (Baja California), the Pacific Bonito, Sarda chiliensis (Baja California), the Pacific Chub Mackerel, Scomber japonicas (Baja California) and the Wahoo, Acanthocybium solandri (Baja California).
From a conservation perspective there are various reports that there has been a dramatic decrease in the global population of scombridae fishes that approach 75% over the last 40 years. Human influence on the scombrids has rendered at least five species to become endangered or vulnerable to extinction: the Albacore, Thunnus alalunga – Near Threatened; the Bigeye Tuna, Thunnus obesus – Vulnerable; the Monterrey Spanish Mackerel, Scomberomorus concolor – Vulnerable; the Northern Bluefin Tuna, Thunnus thynnus – Endangered, and the Southern Bluefin Tuna, Thunnus maccoyyii – Critically Endangered.
There are currently 16 members of the Mackerel or Scombridae presented in this website:
Albacore, Thunnus alalunga
Atlantic Bonito, Sarda sarda
Atlantic Chub Mackerel, Scomber colias
Black Skipjack, Euthynnus lineatus
Bullet Mackerel, Auxis rochei
Frigate Mackerel, Auxis thazard
Gulf Sierra, Scomberomorus concolor
Pacific Bluefin Tuna, Thunnus orientalis
Pacific Bonito, Sarda chiliensis
Pacific Chub Mackerel, Scomber japonicas
Pacific Sierra, Scomberomorus sierra
Skipjack Tuna, Katsuwonus pelamis
Spanish Mackerel, Scomberomorus maculatus
Striped Bonito, Sarda orientalis
Wahoo, Acanthocybium solandri
Yellowfin Tuna, Thunnus albacares