The Billfish Family

You can’t talk about the differences of swordfish vs marlin without talking about their similarities first. Both marlin and swordfish are members of the esteemed billfish family and popular among Louisiana fishing charters.

Billfish are one of the most advanced animals on the planet. Billfish are highly migratory and spend their lives moving from one place to the next. They can be found in all oceans, and some have even been tracked across the Atlantic.

The “sword” of the Swordfish and Marlin

The iconic “sword”, which is visible on all billfish, regardless of whether they are swordfish or marlin, can be seen at the front of every fish’s body. It is called a “rostrum” and is used to slash and stun their prey. It makes for a quick snack as they circle back to complete the task.

How Swordfish and Marlin swim

All billfish possess advanced swim bladders which allow them to quickly change depths without consuming a lot of energy. Swordfish, for example, can reach depths of around 1,500 feet during the day. It is important to have an understanding of the water column before you fish for them.

Marlin vs Swordfish

There are some easy ways to tell the difference when talking about Marlin vs Swordfish. Although, if you’re like most people new to sport fishing, you may consider swordfish and marlin to be the same type of fish species. This is due to their general appearance. Even though these two large marine creatures have similarities, they’re different in several ways, such as their size, their fins and taste. So before you start fantasizing on what it feels like to catch a blue marlin, here are three ways they differ, along with some suggestions on how to prepare swordfish and marlin dishes.

blue marlin

 Blue Marlin


If you’ve ever read Ernest Hemingway’s “The Old Man and the Sea“, you may remember how an old fisherman struggled to catch a marlin. The most distinguishing feature of a marlin is their spear-like snout or bill and dorsal fin, which forms a crest, reaching forward. The upper jaw of a marlin is long. Furthermore, the spear can be deadly to prey, which is primarily squid and smaller fish. This makes marlins one of the top sea predators.

Marlins have a reputation for being exceptional swimmers as they can swim as fast as 50 mph. These popular, strong sporting fish can be found in the deep-sea tropical regions of the Pacific, Atlantic and Indian Oceans. Marlins have a long lifespan with females living as long as 30 years and males reaching around 20 years.




Also known as broadbills, swordfish are salt-water, predatory and migratory fish characterized by their flat, long bill. Their bodies are round and elongated. They get the name swordfish from their bill, which resembles a sword. Interestingly, you can determine the age of swordfish by looking at their annual growth rings that can be found on the fin rays.

Swordfish have a heating mechanism, found next to their eyes, that helps in conserving heat. Besides conserving heat, this heating mechanism also improves the vision of the swordfish, and makes them better hunters. Used much like a spear, their sword-like organ is designed for slashing prey.

How to tell a Marlin from a Swordfish

Although marlin and swordfish are both large fish, these fish species have several differences, such as:

  1. Marlin vs Swordfish size

One way to tell the difference between a marlin vs swordfish is size. In fact, the largest marlin species, the blue marlin, is longer than 16.4 feet, weighing up to 1,400 pounds vs swordfish, which are smaller, only reaching 9.8 feet and weighing 1,430 pounds.

  1. Marlin vs Swordfish dorsal fin and body

Another difference of a swordfish vs marlin is the dorsal fin, which are the fins on their back. The dorsal fin of a marlin resembles a sail vs a swordfish, whose fins look much like the fins of a shark. What’s more, marlins have a tubular, smooth body, which is unlike the elongated, round body of swordfish.

  1. Marlin vs Swordfish taste

The pink flesh of marlin tastes much like swordfish, but swordfish is considerably lighter. Marlin is a fatty fish, consisting of a high-fat content. Thus, marlin flesh is very dense, similar to tuna, having a strong flavor. On the other hand, marlin has a milder flavor than that of swordfish.

swordfish vs marlin

Fishing for Swordfish vs Marlin

While there are many differences between them, hunting for swordfish vs marlin is somewhat similar. The most important thing you need is an experienced deep sea fishing charter captain. An experienced fishing captain knows the right time and place to improve the chances of catching either a great marlin or swordfish.

Would you like to go on a Gulf of Mexico sport fishing adventure of a lifetime? Whether you’re fishing for marlin or swordfish or any of the other types of fish anglers can expect to find in the Gulf of Mexico, Louisiana Fishing Charters can help. Captain Troy has over 30 years of experience deep sea fishing in the Gulf. Contact us to learn more about our wide range of fishing excursions.

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Where can you catch Swordfish and Marlin

Both swordfish and marlin reside in deep water. A good place to start is close to the edge of the continental shelf – the place where the relatively shallow water around land drops off into the deep blue abyss of the open ocean. They frequent the continental shelf drop-off where ocean currents upwell nutrient rich water. These areas contain high concentrations of baitfish, and the billfish are all over them. You can also find marlin and swordfish closer to shore around underwater seamounts and other seafloor features that attract schooling baitfish.

cooking marlin vs swordfish

Recipe ideas for Marlin and Swordfish

Both Swordfish and Marlin can taste great if cooked properly. While there are many ways to prepare either Marlin or Swordfish, here are what we feel are the best.

How to cook Swordfish

The best way to prepare swordfish is filleting it into steaks that can be grilled since this fish’s flesh is quite firm. As a result, you can prepare swordfish in a variety of more ways than what can be done with other more delicate fish. An example is placing swordfish steaks on skewers. You could also prepare swordfish as a fish soup, using larger chunks of the fish. Another way is to pan-fry your swordfish or consume it sashimi-style.

How to cook Marlin

Marlin is best when served sashimi style, which is raw, uncooked meat without rice. Don’t cook it entirely. Once done, cut the marlin into thin slices. Sprinkle your marlin with some sesame seed oil drops, fresh coriander and lime juice for a tasty Asian appetizer. You could also eat marlin in sushi, which has rice. You can also quickly sear marlin on all sides and serve it rare like a tuna steak. There’s also Peruvian-style marlin.

However you decide to prepare your tasty meal and whatever your preference of swordfish vs marlin, you can enjoy eating a well earned meal that you caught and cooked yourself!

Did you enjoy this post? Now let’s compare Bluefin vs Yellowfin Tuna!