Billfish: Everything You Need to Know

Billfish are large, saltwater fish that have long, pointed bills. The bill fish family includes sailfish and marlin, which make up the family Istiophoridae. The swordfish are a sole member of the family Xiphiidae.

The two fish families in question, billfish and marlin, are classified as apex predators. This means that sit at the top of their respective food chain and feed on a wide variety of smaller fish, crustaceans and cephalopods.

large billfish
Large Billfish


Billfish are pelagic and highly migratory. They frequent all the major oceans.

Though they commonly live in tropical and subtropical waters; swordfish typically reside temperate waters. To feed, billfish use their long spear/sword-like upper beaks to slash at and stun prey .

Although their bills can be used for hunting, they are most commonly known to accidentally impale boats. They hold high value to sports fishermen as game fish.

Bill fish are some of the largest fish in the world, and they’re also among the strongest. They natively live in the Atlantic, Pacific, Indian Oceans, as well as Mediterranean Sea.

Types of Billfish

There are four main types of bill fish inhabiting the world’s waters: marlin, swordfish, sailfish, and spearfish.


The swordfish is named after its most prominent feature- an elongated, sharp bill. It often uses this weapon to slash at other fish, which swordfish closely resemble in shape and size.

The coloring of these fish differ, but they are predominantly brownish-black with a white ventral side. They have one tall dorsal fin situated in the middle of their backs and another smaller second dorsal ending near their tailfins.

They are widespread in the tropical and temperate areas of the Atlantic, Pacific, and Indian Oceans because they migrate a lot.

Of all billfish, swordfish are not only among the fastest, but they’re some of the quickest creatures on Earth, reaching speeds up 97 km/h. As sizeable predators, swordfish typically grow to be 120 inches long and weigh in at over 1400 lbs.



The marlin is the largest of all bill fish, featuring an elongated body and spear-like bill that resembles a sailor’s marlinspike.

There are around ten species of blue marlin, with the Atlantic blue marlin being the most prominent. The blue marlin is similar in appearance to the swordfish and sailfish. However, it is much larger and stronger than either of them.

In fact, the blue marlin is one of the largest and strongest predators in the oceans, with very few creatures preying on it other than killer whales and sharks. Besides its impressive strength, the blue marlin is also a popular game fish worldwide.

The female blue marlin, found in tropical and temperate Atlantic waters, can reach a weight of 1,985 pounds and a length of 180 inches.

striped marlin
Striped Marlin


The Sailfish’s massive dorsal fin often stretches the entire length of its back, which is where it gets its name.

Dark blue on the upper body and white under the belly, swordfish are top predators that can weigh up to 220 lbs and grow around 132 inches long. Their design features a long, sharp upper jaw which they use as a deadly weapon to hunt down prey.

Sailfish are really fast. In fact, they’re considered the fastest marine creature in existence, being able to swim at speeds exceeding 109 km/h. They live in the epipelagic zones of the Pacific and Atlantic Oceans. Newly hatched sailfish are easy pickings for other fish that consume plankton as their main diet.

Sailfish Breaching


The spearfish is a pelagic billfish that inhabits open ocean waters. It is typically characterized by its lean, lightweight appearance and dark blue, spotless dorsal fin.

Although some species of spearfish can weigh up to 115 pounds and grow as long as 100 inches, most average between 50-75 inches and 20-60 pounds.

There are four types of spearfish: long bill, short bill, Mediterranean, and round scale.

The longbill and roundsacle spearfish live in the waters of the Atlantic Ocean while the shortbill variety is only found int he Indian and Pacific Oceans.

The Mediterranean spearfish is most commonly found near the surface of the 200-meter deep sea.

In conclusion

Billfish are large and predatory, distinguished by their sleek body and signature long, flat spear-like bill.

Lightning-fast and with spectacular sword-like bills, these bill fish are some of the most magnificent creatures in the oceans.

Although more people are fishing for fun and profit, this has actually caused a drop in certain species’ populations. We need to come up with solutions to protect these animals from becoming extinct.


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