Pic o’ the Week: Baby Swordfish

You may have seen the picture circulating online of a tiny baby swordfish on a person’s finger. The baby is tiny, and notably, it already has a long bill — the “sword” that its common name refers to. Could this be true, or is it a photo editing trick that’s blazing across the internet?

It’s essentially true, though it’s not quite a sword at hatching time. When swordfish eggs hatch the larvae have a short snout and prickly scales. They measure about 4 mm long and are pelagic, or open-water, larvae. The short snout begins to develop into the longer bill when the larvae reach 12 mm in length.

This teeny swordfish and its tiny bill are cute to us humans, but make no mistake – swordfish bills are deadly. As this baby grows up it will use its bill, slashing it back and forth, to stun or injure its prey. 

Photo by Juan C. Levesque, in Florida Sportsman

We’ve all probably seen pictures of swordfish caught by fishermen. Their size and bills are impressive to sportfishers. After all, mature swordfish can grow to 4.5 meters long and weigh up to 650 kg. And here’s some good marine biology trivia for you: Despite their long bills, Swordfish (Xiphias gladius) are the sole member of the Xiphiidae family and are not in the billfish family, Istiophoridae.

More Fun Facts About Swordfish:
{*from the biologists at Marine Bio and NOAA Fisheries}

• Females lay between 1-29 million eggs, which are fertilized externally
• The eggs begin developing into embryos about 2.5 days after they’re fertilized
• Swordfish reach sexual maturity between 5-6 years of age and live up to 9 years 
• They have special eye muscles and a heat exchange system that allows them to swim in deep, cold water in search of prey
• Swordfish feed on a variety of fish and invertebrates such as squid
• They feed at the top of the food chain and are rarely preyed on by other animals. Sharks and larger predatory fishes may sometimes eat juvenile swordfish
• Atlantic swordfish are one of the fastest predators in the ocean. Their streamlined body allows them to swim at high speeds up to 50 mph