The oceans are filled with many different types of fish that people consume in great numbers. Mackerel and sardines are both popular choices due to their nutritional value and versatility. However, some of the smaller fish look so much alike, or are served in such similar ways, that it can be hard to tell them apart. If you’ve ever wondered about the differences between mackerel vs. sardines, keep reading to find out what sets these popular fish apart.
Comparing Mackerel and Sardines
| Mackerel | Sardine | |
|---|---|---|
| Size | Weight: 1.5-2.2 pounds on average Length: Up to 26 inches | Weight: 0.2-4.5 ounces Length: 6-15.6 inches |
| Appearance | Torpedo-shaped, green-blue body; Two dorsal fins and two anal fins; finlets behind the dorsal and anal fins; forked tail | Elongated, flat silvery body; no scales on the head; single dorsal fin, finlets near forked tail |
| Diet | Carnivores; crustaceans, squid, fish, other invertebrates | Omnivores; zooplankton, phytoplankton, debris, parasites |
| Scientific Families | Family Scombridae; subfamily Scombrinae, genus Scomber | Family Clupeidae; genera Sardina, Dussumieria, Escualosa, Sardinops, and Sardinella |
| Uses | Human consumption; sold frozen, fresh, and canned | Human consumption, bait fish, animal feed, oil; Most often canned but can be purchased frozen |
The 5 Key Differences Between Mackerel vs. Sardines
The Atlantic mackerel can reach up to 7.5 pounds, but most average less than 3 pounds.
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The biggest differences between mackerel and sardines can be found in their size, appearance, diet, scientific families, and uses. Take a closer look at each of these features in the following paragraphs.
Size
The average mackerel is larger than the average sardine. The most common and economically important mackerel in the U.S. is the Atlantic mackerel. These mackerel average between 1.5 and 2.2 pounds, with the largest on record weighing 7.5 pounds. All sardines are small fish, generally weighing between 0.2 and 4.5 ounces on average.
Mackerel are also much longer than sardines. Mackerel grow between 10 and 16.6 inches on average, but they can grow up to 26 inches in length. Sardines generally measure between 6 and 15.6 inches in total length.
Appearance
Sardines typically have silver bodies and no scales on their heads.
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Sardines and mackerel have substantial differences in appearance. These unique qualities make it easy to tell them apart at a glance. Mackerel have a green-blue body with dark stripes on the top and lighter coloring on the bottom. Sardines generally have silver bodies with no scales on their heads.
Mackerel have torpedo-shaped bodies, while sardines have elongated, flat bodies. Mackerel have two dorsal fins and two anal fins, with finlets behind the anal and dorsal fins. Many sardines have a single dorsal fin and a single anal fin, but some sardine species can also have small finlets behind the anal fin. Both mackerel and sardines have forked tails.
Diet
Sardines are omnivores that feed on both phytoplankton and zooplankton.
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Mackerel are carnivores. They primarily feed on crustaceans, such as krill, shrimp, and copepods, tiny crustaceans that are a type of zooplankton, or animal-based plankton. Mackerel also eat squid, some smaller fish, and other marine invertebrates.
Sardines are omnivores. They eat phytoplankton, which is plant-based plankton, and zooplankton such as copepods, decapods, crab eggs, and young barnacles. They may also feed on debris in the water and parasites found on other fish.
Scientific Families
Sardines and mackerel are from different scientific families. There are over 30 species of mackerel in the Scombridae family. True mackerel belong to the Scombrini tribe, especially the genera Scomber and Rastrelliger. For instance, Atlantic mackerel belong to the subfamily Scombrinae and the genus Scomber.
There are over 21 species of sardine in the Clupeidae family. However, they may come from several genera, including Sardina, Dussumieria, Escualosa, Sardinops, and Sardinella. The European pilchard, one of the most common sardines, is considered the only “true sardine” as it belongs to the Sardina genus.
Uses
Atlantic mackerel are a popular food low in mercury and high in omega-3 fatty acids.
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Both mackerel and sardines are primarily caught for human consumption. Some of the most common mackerel and sardines, the Atlantic mackerel and the European pilchard, are low in mercury and high in nutritious omega-3 fatty acids. However, some, like the king mackerel, are high in mercury and should be avoided. Spanish mackerel has moderate mercury levels and should not be eaten very often.
Mackerel is sold frozen, fresh, or canned. It is served smoked, grilled, or poached. It is also fried in oil, made into soups, and roasted. This fish has a strong taste, whereas sardines typically have a milder flavor.
Sardines are most commonly sold in cans, but they can be found frozen and fresh, too. They may be eaten fresh out of the can, baked into pies, smoked, or even pickled. Sardines are also used as bait fish, animal feed, and as a source of oil.
