The Atlantic mackerel, Somber scombrus, supports one of the most important commercial fisheries and supports a significant sport fishing interest. The fish is a close relative of the tuna. The attraction of mackerel as sport fish is due primarily to the streamlined body, forked tail, pointed head, and high-speed swimming. An unusual characteristic of the mackerel is that it does not possess a swim-bladder. Mackerel are found in large schools in the Atlantic Ocean from the New England coast to the Carolinas, and in the Eastern Atlantic south to Spain.
The average size of mackerel is less than a pound (1/2 kg) although some fish weighing 2 lb (1 kg) are found in deeper water. Mackerel feed on pilchards, herrings, small schooling fish, and small crustaceans such as shrimp.
At spawning time female mackerels lay up to 500,000 eggs, which float due to the presence of oil droplets. Spawning occurs in the mid Atlantic states in the latter half of May and throughout June, and a few weeks later further north. The eggs hatch in about 96-120 hours, the lower the temperature the longer it takes for them to hatch.
The Atlantic mackerel can be distinguished from other species of mackerels by the pattern of up to 24 wavy black lines along the sides of its body above the
lateral line. The chub mackerel, S. japonicus, is smaller than the Atlantic mackerel but closely resembles it in its behavior and physical characteristics (but has fewer, fainter black markings than the Atlantic mackerel).
The Pacific mackerel is the only mackerel found on the west coast of North America and is the same species (S. scombrus) as is found in the Atlantic Ocean. Pacific mackerels are found from Chile to Alaska and along the coasts of Japan and the mainland coast of Asia.
The kingfish of king mackerel, Scomberomorus cavalla ranges widely in size from under 10 lb (5 kg) to more than 20 lb (9 kg). Some specimens caught in nets have been reported to weigh 100 lb (45 kg) and to exceed 5 ft (1.5 m) in length. The king mackerel has a blue-green back and silver sides, and a lateral line that is positioned high near the head and quickly descends below the second dorsal fin. King mackerel are found in great numbers in the Caribbean in the spring time migrating up the Atlantic coast with some entering the Gulf of Mexico.
The Spanish mackerel (S. maculatus) is a close relative of the king mackerel but grows only up to 12 lb (6 kg), the average being under 2 lb (1 kg). In warm offshore and inshore waters, the Spanish mackerel is subjected to heavy commercial and sport fishing.
The sierra, S. sierra, is very similar to the Spanish mackerel (some taxonomists consider them to be the same species) and is found in warm waters from Baja California to South America.
The cero, S. regalis, is found together with the Spanish and with king mackerels, and is characterized by rows of yellow or brown spots along its sides. The frigate mackerel, Auxis thazard, closely resembles the tuna because it has a lunate tail rather than the forked tail typical of mackerels.
See also Tuna.
Hoese, H. Dickson, and R. H. Moore. Fishes of the Gulf of Mexico, Texas, Louisiana, and Adjacent Waters. College Station: Texas A&M University Press, 1998.
Migdalski, E. C., and G. S. Fichter. The Fresh & Salt Water Fishes of the World. New York: Greenwich House, 1982.