How Big Do Swordfish Grow?

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Key Takeaways:

  • Swordfish can grow to be very large, over 1,000 pounds and 14 feet long.
  • Pacific swordfish reach a greater size than Atlantic and Mediterranean swordfish.
  • Females grow faster, live longer, and reach a larger size than males.
  • Swordfish grow about 14 inches per year on average.
  • The average commercial swordfish is 47-75 inches long in the Pacific.


Swordfish are renowned as one of the fastest and largest predators in the oceans worldwide. With their distinctive long, flat bill resembling a sword, these powerful fish are highly migratory and a popular target for commercial and recreational fishing. But just how big do swordfish grow? What is their maximum size and weight? And do factors like gender and geographic region impact their growth?

This comprehensive article will analyze the size dimensions of swordfish in detail. It will provide key facts and statistics on the average and record lengths and weights of these giants of the sea. Regional variations in swordfish size, as well as differences between males and females, will be explored. With abundant data sourced from scientific research and fisheries information, readers will gain valuable insights into the impressive growth capacity of swordfish.

Understanding the size potential of swordfish is important for fishery management and also sheds light on their ecology as fast, formidable marine predators. This article will deliver a deep-dive into swordfish size that both informs and captivates – inviting readers to discover more about these iconic fish.

What Is the Average Size of Swordfish??

How Big Do Swordfish Grow?

Swordfish have a reputation for reaching an enormous size, but what are their actual typical dimensions? Looking at average data is important for understanding their baseline growth statistics.

  • On average, swordfish grow to be up to 10 feet long and weigh 150-200 pounds. However, these are mature adults – swordfish go through a rapid growth phase when young.
  • Newly hatched swordfish measure just 0.08 inches (2 mm) long and weigh only 0.001 ounces (0.03 g). They reach 6.7-13.8 inches (17-35 cm) by 6 months old.
  • By age 1, swordfish average around 26 inches (65 cm) and by age 2, they reach about 47 inches (120 cm). Full adult size is reached by age 5.
  • Swordfish grow approximately 14 inches (36 cm) longer each year until maturation. Growth slows after reaching sexual maturity.
  • Females grow faster and larger on average than males of the same age.

So while “typical” adult swordfish measure about 10 feet and 150-200 pounds, their growth rate from a tiny hatchling to maturity is incredibly fast. They reach near full-size by age 5, packing on over a foot of growth annually in their early years.

What Are the Largest Swordfish on Record??

While the averages reflect normal growth, some swordfish become true giants of the sea. What are the record sizes documented for these massive fish?

  • The maximum reported length of a swordfish is 14 feet 11 inches (4.55 meters) and the heaviest recorded weight is 1,430 pounds (650 kg).
  • In the North Atlantic, swordfish can reach close to the record size, with a documented maximum weight of 1,165 pounds.
  • In the North Pacific, the maximum recorded weight is close to 1,200 pounds and length of 14 feet.
  • One study documented a 645 pound (293 kg) swordfish caught near Chile in the South Pacific.
  • Pacific swordfish in general reach a larger size than those in the northwest Atlantic and Mediterranean.

So while 1,000+ pounds and 14 feet long are extremely rare, some swordfish do reach these record dimensions. The Pacific region tends to produce the largest swordfish specimens globally. Their tremendous size confirms the swordfish’s status as apex pelagic predators.

How Does Size Vary Between Ocean Regions??

While Pacific swordfish attain a greater size than those in the Atlantic, there are some regional differences in fish sizes across ocean basins.

  • In the Atlantic, the largest swordfish are found in the northwest region. One study found average weights of 241 pounds (110 kg) for males and 372 pounds (169 kg) for females.
  • In the Mediterranean Sea, swordfish only reach about 275 pounds (125 kg) on average based on fishery data.
  • In the Pacific, northwest region swordfish also tend to be larger, with averages of 150-280 pounds (70-130 kg).
  • One South Pacific study found average weights of 123 pounds (56 kg) for males and 224 pounds (102 kg) for females.
  • In the Indian Ocean, limited data indicates averages around 110-150 pounds (50-70 kg).

So the northwest Atlantic and Pacific tend to produce the largest swordfish, while the Mediterranean Sea individuals remain relatively small. There are always outliers – super-sized swordfish can turn up in any ocean basin. But location does impact typical dimensions.

Do Females Grow Larger Than Males?

How Big Do Swordfish Grow?

Among individual swordfish, females have a clear size advantage over males. Let’s analyze the key evidence:

  • Females grow faster than males at the same age, maturing around age 5 compared to 4 years for males.
  • Maximum size records are typically from female swordfish. The 1,430 pound record was a female.
  • Female swordfish live longer, up to 9 years or more compared to a 5 year average lifespan for males. More lifespan allows larger growth.
  • Studies consistently show significantly higher average weights for mature female swordfish compared to males. Up to 1.5 times heavier on average.
  • The discrepency in size is linked to reproduction – females make a greater energetic investment in generating eggs.

So across ocean basins, female swordfish mature later and attain significantly larger dimensions than male fish during their longer lifespans. The evidence clearly points to gender as a key factor influencing swordfish growth.

How Fast Do Swordfish Grow Each Year?

Swordfish undergo a period of extremely rapid juvenile growth before their rate slows as adults. What is their annual growth trajectory?

  • Newly hatched swordfish grow about 0.4 ounces (11 grams) per day initially. Their growth is nearly exponential early on.
  • By 6 months old, swordfish reach about 13.8 inches (35 cm) from their 0.08 inch hatch length – gaining well over an inch per month.
  • Growth slows slightly but remains fast, with swordfish reaching around 47 inches (120 cm) by age 2.
  • Swordfish grow approximately 14 inches (36 cm) longer each year until maturation around age 5.
  • After reaching adulthood, linear growth continues but slows to about 6 inches (15 cm) per year.
  • So most growth occurs early in life, with swordfish gaining up to 14 inches annually and then slowing to less than half that rate when mature.
  • The bulk of weight gain also happens in juvenile stages before adulthood.

The fast yet decelerating growth allows swordfish to reach 10 feet so quickly. Their growth rate in the first years of life is remarkably fast for any fish species.

What Is the Average Size of Commercially Caught Swordfish?

For fisheries targeting swordfish, what are the typical sizes landed?

  • In the Pacific Ocean, the average commercial swordfish catch is 47-75 inches (120-190 cm) long.
  • In the Indian Ocean, catch averages around 79 inches (200 cm).
  • In the Atlantic, average lengths are approximately 47-98 inches (120-250 cm).
  • So commercially caught swordfish range from just under 4 feet to over 8 feet in length.
  • But recreational catch averages are smaller, around 37 inches (95 cm).
  • There are minimum size restrictions in most fisheries to allow juvenile swordfish to mature before potential capture.

So while monster 14 foot swordfish make headlines, commercial fishing targets smaller mature adults averaging 5-8 feet long. Recreational landings are usually even smaller juveniles or young adults.

How Does Fishing Pressure Impact Swordfish Size?

Extensive commercial fishing targeting large adults may now be reducing swordfish size averages.

  • Heaviest swordfish catches now are 300-400 pounds versus 600 pounders in the past.
  • One study in the Mediterranean found a 33% decline in average weight from the 1930s to 2000s.
  • Pacific swordfish size dropped sharply when longline fishing expanded in the 1960s-80s.
  • Minimum size limits aim to protect juveniles but may increase pressure on larger adults.

So while swordfish do reach 14 feet and over 1,000 pounds, intensive fishing means fewer ever grow that big today. Conservation measures try to strike a balance for sustainable fisheries.


Swordfish stand out for their ability to attain incredibly large sizes as apex ocean predators. Although adults average a length around 10 feet and 150-200 pounds, the maximum documented size is a mammoth 14 feet and over 1,400 pounds. Regional factors play a role, with Pacific swordfish reaching larger dimensions than Atlantic/Mediterranean individuals. Within each ocean basin, some areas produce larger fish, like the northwest Atlantic and Pacific. Gender also impacts growth patterns, as females grow faster, live longer, and ultimately become much larger than males. With rapid juvenile growth of up to 14 inches per year, swordfish reach their impressive size quickly but their growth decelerates after maturing around age 5. Intensive commercial fishing has reduced the number of monster-sized swordfish over time, making the maximum sizes now a rarity. But the evidence confirms swordfish can still grow to be giants, and understanding their growth capacity highlights their prowess as pelagic hunters. Swordfish represent an iconic and enduring part of our ocean’s heritage.

Frequently Asked Questions About Swordfish Size

How big is a newborn swordfish?

Newborn swordfish are tiny, measuring just 0.08 inches (2 mm) long and weighing only 0.001 ounces (0.03 g) at hatching. They are vulnerable as larvae but grow rapidly.

What is the growth rate of juvenile swordfish?

Extremely fast growth characterizes juvenile swordfish. They reach about 13.8 inches (35 cm) by 6 months old and gain around 14 inches (36 cm) in length each year early on. Some gain over an inch per month.

How fast can swordfish swim?

Swordfish are one of the fastest fish in the ocean. They have been clocked reliably swimming over 60 mph to hunt prey. Some unconfirmed reports have recorded them at over 80 mph.

Where are the largest swordfish caught?

The northwest Atlantic and Pacific regions produce the largest swordfish on average, with maximum confirmed sizes over 1,165 pounds. The Pacific generally has larger swordfish than the Atlantic.

At what age do swordfish reproduce?

Swordfish reach sexual maturity around 5 years old. Females mature at a slightly older age than males on average. They must attain substantial size before reproducing.

What is the average weight of a swordfish?

The overall average weight for an adult swordfish is 150-200 pounds. But regionally, averages range from about 110 pounds in the Indian Ocean to over 350 pounds in the North Atlantic.

How does climate change affect swordfish?

Rising ocean temperatures may impact swordfish reproduction and shift suitable habitat over time. But as a highly migratory species, they may adapt more readily than other fish.

What eats adult swordfish?

Large sharks and marine mammals like orcas and sperm whales are the only predators of full-grown swordfish. Their meaty size and speed makes them challenging prey.

How long do swordfish live?

Swordfish have a lifespan of about 5 years on average for males and up to 9 years for females. Their rapid growth when young is an adaptation to their shorter life expectancy

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