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Marine Species: Billfish

It's rare to see a billfish on a dive, although you can snorkel with them seasonally off the Yucatan Peninsula. Here are some quick facts about billfish.

While it’s quite rare to encounter a billfish on a dive, some marine enthusiasts may have been lucky enough to see a blue marlin or swordfish leap from the ocean. One of the ocean’s most spectacular and fastest species, billfish are apex predators that roam the pelagic zone. They live in tropical, sub-tropical and temperate waters. Unfortunately, they are a highly prized game fish due to their speed and strength. This has resulted in plummeting billfish numbers in various areas of the world, especially the Caribbean and Pacific tropics. 

Marlin (Blue, white, black and striped)

Native to the Atlantic Ocean, the Atlantic blue marlin is one of two species of blue marlin. The largest of all billfish, the blue marlin can reach up to 16 feet (5 m) and weigh as much as 1,800 pounds (820 kg). The fish is also capable of speeds up to 100 miles per hour (160 kph). Blue marlin dine on pelagic fish, especially tuna, dorado, squid and even dolphin. The marlin uses its bill to strike and stun fish, not pierce them, which is a common misconception. While a top predator, the blue marlin is not without enemies. Mako sharks, killer whales and false killer whales all predate the blue marlin. 

The white marlin, like the blue marlin, lives in sub-tropical and tropical areas of the Atlantic. Preferring warmer waters, white marlin tend to populate banks and shoals where they feed on mahi-mahi, squid and larger pelagic species like tuna. Smaller than the blue marlin, white marlin can grow to over 8 feet l0ng (2.5 m) and weigh as much as 176 pounds (80 kg).

Perhaps the most visually stunning of all billfish, the striped marlin lives in the Indo-Pacific range. They’re commonly spotted off Mexico and Costa Rica and venture as far as Oregon. The distinctive light blue stripes or vertical spots on the side give the species its name. Sardines are its primary food source yet, like all other billfish, it will target squid. Larger than the white marlin, striped marlin can reach over 12 feet long (4 m) and weigh over 397 pounds (180 kg).


There are two species of sailfish: the Atlantic and the Pacific. It’s more common to see Atlantic sailfish, however, especially off the Yucatan peninsula where many operators allow snorkelers to observe these majestic creatures feeding on sardines between December and March. When raised, the distinctive dorsal fin of the sailfish can flash a majestic blue, purple and green tint depending on its excitement levels. Reaching over 12 feet long (4 m) and weighing 220 pounds (100 kg), the sailfish is the fastest fish of all, capable of reaching bursts of speed up to 70 mph (112 kph).