What Is the Life Cycle of a Swordfish?

The swordfish, or “Xiphias gladius,” starts as an egg, hatches when the zygote reaches about 0.15 inches long and lives for about 9 years. Eggs are fertilized externally after females spawn anywhere from 1 to 29 million ova. The long bill at the end of a swordfish’s nose begins to develop when it reaches 1/2 inch long. Swordfish reach sexual maturity at 5 to 6 years.

Swordfish change drastically from egg to adult. Females lay eggs merely 0.06 inches wide. Embryos develop 2 days later. The large dorsal fin starts to shrink as fish grow after hatching. Juveniles have rough scales that remain on their bodies until they reach about 3 feet long. Adult fish do not have scales or teeth.

Swordfish specimens reach up to 15 feet in length and weigh 1,400 pounds when fully grown. Most wild adults taken by fishermen are between 4 and 6 feet long. The largest swordfish taken by fishing tackle weighed in at 1,182 pounds. Female swordfish are larger than males, and all specimens more than 300 pounds are female.

These apex predators eat fish and squid at varying ocean depths. Smaller prey is swallowed whole, while larger fish are stabbed with the swordfish’s long bill. These fish migrate all over the world’s oceans searching for food.