The shark takes its name from one of its primary sources of food—Pacific salmon. Despite this common prey, the salmon shark also eats a wide variety of other marine creatures (see below). These sharks are sometimes mistaken for great white sharks because their body shape and coloring are so similar. But they are much smaller than their relatives.
Interestingly, these predators have the ability to regulate their body temperature. This is a skill limited to a few other fish species. They use vascular counter-current heat exchangers or retia mirabilia. The close proximity of arteries and veins. This creates heat within the shark’s body.
In Japanese waters, where the shark is common, it’s often referred to by other names. These include the Japanese mackerel, sakezame, mokazame, and radukazame.
The salmon shark is a gray-colored shark that, like most large marine animals, has a paler underside. It has white markings and darker blotches on its underside as well. The shark also has a wide tail with a short ridge running along the upper part of the lower lobe. Juveniles are smaller in appearance but are generally identical. Both have shorter snouts and a similar appearance to a great white shark, although significantly smaller. Similarly to great whites, and other oceanic sharks, the salmon shark has blade-like teeth which is used to efficiently kill its prey.
These sharks grow between 6.5 and 8.5 feet, or 198 – 260 cm, and can weigh up to 485 pounds, or 220 kg. Male sharks reach a slightly smaller size than their female counterparts, a familiar trait in sharks. The largest-ever confirmed sighting of a salmon shark was 10 feet, with the highest estimated weight at 992 pounds. It’s believed these sharks can live to around twenty-five years old.
Salmon sharks live primarily in offshore waters and oceanic environments but it’s not uncommon to see them inshore, just off the beach line. They range from the sub-Arctic to subtropical waters. It can be found throughout the North Pacific Ocean as well, with a range as far south as the Sea of Japan and as far north as Alaska.
Interestingly, and as noted by “Growth and maturity of salmon sharks (Lamna ditropis) in the eastern and western North Pacific, and comments on back-calculation methods,’ there is a difference in range depending on sex and age. Eastern populations of these sharks are primarily female, while the Western populations are mostly male. It’s not known exactly what causes this separation.
Many sea creatures rely heavily on the water temperatures around them. However, the salmon shark populations are different in this respect. Despite fluctuations in the temperature of the surrounding water, the shark has the ability to regulate its own body temperature. Retia mirabilia, or counter-current heat exchangers, are utilized by the salmon shark. They are a series of veins and arteries that sit close to each other and warm up the cold blood that comes from the gills and visa-versa. This reduces the loss of heat from the blood. This allows the salmon shark to thrive in cool temperate waters.
Some of these colder waters include the Sea of Okhotsk and the Bering Sea in the Northeast Pacific to waters in Southern Baja California near Mexico, covering vast areas of the ocean.
It’s common for salmon sharks to feed on different fish, herring, squid, salmon, birds, sea otters, and more. Some of these fish include halibut, pollock, sablefish, tunas, codfish, sardines, and more.
The salmon shark, like other sharks, is ovoviviparous. This means that they develop eggs inside the womb that remain there until the mother is ready to give birth. The embryos feed on the ova produced by the mother. A typical salmon shark litter size is between two to six pups.
It’s believed that females reach maturity at around 8-10 years of age, with males maturing by five. The gestation period is around nine months. In pups, it is said that there are around 2.2 males born for every female.
Threats to Salmon Sharks
Salmon sharks are not a particular threat from fisheries and commercial fishing. There do not appear to be any commercial fisheries that target salmon sharks. But, like almost every marine creature, they are sometimes captured as bycatch but are usually discarded. They are often cited as a nuisance because of their habit of damaging fishing gear.
They are also liable to consume parts of the intended catch. Due to the frequency of these sharks being captured as bycatch, their conservation status is considered to be vulnerable to extinction. This is heightened by the development along seashores and around coastal waters where nurseries are located.
Salmon sharks live in relatively high levels of abundance. A good sign of their population health is that they are currently marked as animals of least concern on the IUCN Red List of Threatened Species. Their population within the western central pacific, eastern central pacific, and northwest Pacific, to name some, are prime examples of this.
When these sharks are caught, sometimes their fins are cut off and sold. Their flesh is uncommonly sold in the United States, but it does happen. More often, products like leather and oil are created by the captured salmon sharks.
They are also not considered a threat to human beings. They are likely capable of injuring humans, but few, if any, attacks have ever been reported. Salmon sharks are sometimes hunted by other larger sharks, their biggest natural apex predator.
Facts About Salmon Sharks
- The salmon shark, like other sharks, is ovoviviparous.
- The salmon shark is a gray-colored shark that, like most large marine animals, has a paler underside.
- Male salmon sharks are usually smaller than female salmon sharks.
- Salmon sharks live primarily in offshore waters, but it’s not uncommon to see them inshore, just off the beach line.
- Different areas of the world’s oceans are inhabited by male and female sharks.
- Female sharks are primarily found in the east, and male sharks in the west.
- These sharks grow between 6.5 and 8.5 feet and can weigh up to 485 pounds.
Are salmon sharks dangerous?
The salmon shark is a “potential” danger to human beings. This means that it has the ability to harm human beings but there are few, if any, reported injuries or attacks by salmon sharks.
How long is a salmon shark?
Salmon sharks can grow between 8-10 feet long. There have been reports of some significantly longer. But, like most outliers, these sights often go unconfirmed.
Are salmon sharks good to eat?
Some people like to eat salmon sharks. For example, in Japan, the heart is considered a delicacy. Some fishermen in Alaska and other parts of the world also choose to fish for these sharks.
Are salmon sharks related to mako sharks?
Yes. The salmon shark belongs to the Lamnidae family. This family includes the shortfin and longfin mako shark, the porbeagle, also known as a mackerel shark, and the great white.
Can you own a salmon shark?
While it is legal to own a salmon shark, as it is with most sharks, it’s unlikely that the salmon shark would make a good pet. They are large animals, although not as large as their relatives, the great white, and would require specialized care.