Skip to main content

Probably better recognized as one of the species that make up its group (Swordfish) rather than its general name, Billfish are large fish that are recognizable by their long, pointed snouts.

You’ve probably seen them (or at least pictures of them), if their name doesn’t ring a bell. They include swordfish, marlins, and sailfish, among others. Those long, spear-like snouts help them hunt, and these fish are apex predators (meaning they don’t normally have predators who hunt them). They are also large, with their largest species (the Atlantic Blue Marlin) weighing over 800 kg and some of their members being over 4 meters long. Living in all of the world’s oceans, they sometimes are commonly found in tropical, sub-tropical, and temperate waters, so they’re not entirely unexpected along the coasts of the First State.

Here are some of the species you might encounter:

Blue Marlin

Delaware’s largest billfish.

Its body is cobalt blue on top with 15 blue vertical bars (stripes) on the sides and a silvery white belly.



Dark blue along the upper half of the body, fading to brownish-blue on the lower sides to silver white on the belly

The first dorsal fin is high, sail-like, blue-black and covered with many small black spots.

The other fins are silver-blue.

On the sides there are 15 to 20 vertical bars (stripes) consisting of several small blue spots.


White Marlin

Smaller than many other billfishes.

The body is dark blue above and silvery white below, with brown spots on the sides of the white portion.