American Oceans

Striped Marlin

The majestic striped marlin is one of the most unique and powerful pelagic fish in the world. The striped marlin, or Kajikia audax as it’s known in the scientific community, belongs to the class of billfish, and it’s similar to swordfish and other marlin species.

Striped Marlin or Kajikia audax in the ocean

Today, we’re going to take a closer look at everything you need to know about this prolific Pacific sportfish.

From their characteristics and appearance to their lifecycle, reproductive habits, habitat, and more.

Characteristics & Appearance

Thanks to its unique look and long bill, the striped marlin is one of the most easily recognizable species in the ocean. Here’s how you can spot a striped marlin in the wild the next time you’re on the Pacific.

Weight & Length

The striped marlin is the smallest of all marlin species, but it isn’t tiny by any stretch of the imagination.

Striped Marlin side view of length

A striped marlin can tip the scales at nearly 500 pounds, and the largest specimens can grow to over 12-feet in length. The average mature striped marlin is about 410 pounds and 11-feet long.

Physical Characteristics & Color

Striped marlins are some of the most beautiful and unique fish in the ocean. They possess many physical characteristics that make the species easy to recognize, even compared to other marlins.

Striped Marlin sword-like bill physical characteristics

The standout physical characteristic of the striped marlin is its distinct sword-like bill. Compared to other marlin species, the bill of a striped marlin is a bit more slender, and it’s also fairly blunt, and the fish has tons of tiny teeth, so it can easily break down its prey.

The coloration of a striped marlin is similar to blue marlin, and both fish have a dark blue band that runs from the bill to the tail, and the color fades to silver about halfway through the fish.

The key difference between the striped marlin and blue marlin is that striped marlins have 10-20 striations of lighter blue that run across the sides of the fish’s body.

Striped marlins have a long, torpedo-like body, which helps them reach impressive speeds in the water.

These fish have a flexible set of pectoral fins, a large dorsal fin with a small adipose fin before the tail.

Lifespan & Reproduction

Striped marlins typically live for about ten years, and they reach full maturity within 2-3 years after birth. Male striped marlins reach maturity a bit more quickly than females do.

While they’re solitary fish, they will pair off into small schools based on size during spawning season.

Reproduction is external with these fish, and a female striped marlin will release millions of eggs during a spawning session, and a male will then fertilize the eggs.

Spawning sessions occur regularly through the summer, with female marlins releasing over 100 million eggs across dozens of spawning sessions.

Juvenile striped marlin are susceptible to a variety of ocean predators. As the fish nears maturity, predation risk is significantly lower thanks to its large size and intimidating bill.


Striped marlin are a highly migratory pelagic species, and they can be found throughout the Pacific and Indian oceans.

The fish inhabit tropical and subtropical waters, as they rely on warm water to regulate their body temperature.

The species is highly migratory, and they spend the winter months closer to the equator, where the water is warmer.

During the summers, they move north to find the more temperature waters of the North Pacific and Indian oceans.

Where Do Striped Marlin Live?

Striped marlin live offshore, in waters as deep as 300 meters. It’s rare to see striped marlin in coastal waters unless there are areas with massive cliffs or drop-offs where the marlin can easily reach deeper water.

Marlins spend most of their day hanging around deeper waters. At night, they ascend to the surface to feed.

During the spawning season, striped marlin head to the central Pacific or southern Pacific off the coast of Mexico.

Food & Diet

Striped marlins are apex predators with a carnivorous diet. The species is known to feed voraciously at the water’s surface during nighttime, and they eat a wide variety of different small fish and cephalopods.

What Do Striped Marlin Eat?

Striped marlin have a varied diet mostly composed of fish and squid. Striped marlin feed primarily on small fish such as anchovy and sardines. They’re also happy to make a quick meal of squid and certain crustaceans.

Striped marlin feed primarily at night and at the water’s surface, where small fish like anchovies and sardines are abundant.

Beyond smaller prey, striped marlin will also feed on trevally and smaller tuna species, which are significantly larger than the baitfish, which make up most of their diet.

When targeting larger prey, striped marlin will use their bill as a weapon, thrashing it back and forth to incapacitate their prey before feeding.

Reports suggest that marlin will also attack and eat smaller shark species that live near the surface.

Threats & Predators

Striped marlins sit fairly high on the food chain, but they still face threats from many sources, including humans, predators, and climate change.

Human Threats

Humans represent the largest threat to striped marlins, as they’re a prized trophy fish that thousands of anglers across the world hope to grapple with each year.

Beyond recreational fishing, striped marlin are also targeted commercially, and they’re a popular fish in kitchens across the world.

Climate Change & Global Warming

Climate change and global warming may prove to have a significant effect on the distribution and overall health of the striped marlin species.

These highly migratory fish constantly move with the seasons to inhabit the most temperate waters and best feeding environments.

As ocean temperatures warm, the migration patterns and distribution of fish is sure to change as the striped marlin seek out the most habitable environment.

It remains to be seen what the overall implications of climate change will mean for this species.


Striped marlins are a massive species that can grow to over 12-feet long. Plus, their long bill is a massive deterrent to other predators.

While toothed whales and large sharks occasionally grapple with and kill striped marlin, they don’t have any legitimate threat from predators.

Other Threats

Beyond human, environmental, and predatory threats, striped marlin are also susceptible to parasites. Most parasites are nearly harmless to the marlin.

But one species, a worm-like copepod that extends from the back of the fish, can pose problems for striped marlin.

These parasites are rare, and usually, only one or two are present. But, some marlin seems especially susceptible to these parasites, and dozens or hundreds of them can prove fatal to the fish.

Conservation Status

The striped marlin is a relatively sturdy fish with strong population numbers throughout the waters it inhabits.

Populations in the western Pacific and Indian oceans aren’t as strong as those in the eastern Pacific, but this fish isn’t endangered or at risk of extinction. The IUCN gives the striped marlin a designation of “near threatened.”

Fun Facts About Striped Marlin

Striped marlin are one of the most majestic animals that roam the open ocean, and there are so many cool things to learn about them. Check out some more fun marlin facts below.

  • Striped marlin have the tallest dorsal fin of all marlin despite being the smallest of the three species
  • The average female striped marlin produces between 10-30 million eggs in each litter, and up to 120 million eggs during each spawning season
  • The stripes of the marlin will change color in response to danger or excitement
  • The biggest threats to striped marlin are anglers, orcas, and large sharks
  • Striped marlin are considered “near threatened” by the IUCN, and they’re a protected species in most waters
  • Striped marlin use their bill when hunting larger prey and to defend themselves
  • Like most billfish, striped marlin are solitary creatures that mostly hunt and live alone

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