How Do Swordfish Catch Prey in the Ocean Depths?

Marine biologists have long been aware that some ocean predators, such as tuna and sharks, are able to warm their eyes and brains while hunting for prey in cold underwater environments. But they didn’t know why until a groundbreaking study about swordfish from the University of Queensland in Australia revealed a likely explanation. That research determined that warming of their retinas allow swordfish to distinguish light flashes associated with prey movement more accurately. This improved their ability to see moving images and track their prey by as much as 10 times, the researchers found.

Warmer eyes, better hunting:

• It is common to find swordfish in the Pacific Ocean at a depth of 984 feet (300 m), where the temperature can be as low as 37°F (3°C).
• Temperature “must affect transmission speed in nerves and other molecular and neurochemical processes, slowing the whole nerve response down,” the researchers said.
• Contrary to popular belief, a swordfish’s "sword" is not used to spear prey, but used instead to slash at its prey. Once injured, the prey is easier to catch.

Frequently Asked Questions

How do swordfish use their bills to catch prey?

Swordfish utilize their elongated bills to slash at schools of fish, stunning or injuring them. This technique allows the swordfish to easily circle back and consume the incapacitated prey. Their bills are not used to spear, but rather as a tool to increase their hunting efficiency in the ocean depths.

What adaptations help swordfish hunt in deep waters?

Swordfish are equipped with large eyes that enhance their vision in low light conditions found in deep waters. According to research, they also have special organs near their eyes that heat their brains and eyes, improving their sensory performance in cold, deep-sea environments, which is crucial for locating and catching prey.

What is the diet of a swordfish?

Swordfish are opportunistic predators, feeding on a variety of species. Their diet primarily consists of pelagic fish like mackerel, herring, and lanternfish. They also consume squid and crustaceans. The exact composition of their diet can vary based on the availability of prey in their habitat.

How fast can swordfish swim when hunting?

Swordfish are among the fastest swimmers in the ocean, capable of reaching speeds up to 60 miles per hour. This incredible speed allows them to swiftly close in on their prey, making them formidable hunters. Their streamlined bodies and powerful muscles contribute to their impressive swimming capabilities.

Do swordfish hunt alone or in groups?

Swordfish are generally solitary hunters, especially when pursuing prey in the depths of the ocean. They rely on their speed and agility to overtake individual prey rather than hunting in coordinated groups. However, they may be found in loose aggregations when feeding opportunities, like baitfish schools, are abundant.

How does the swordfish's hunting strategy affect other species in the ocean?

The hunting strategy of swordfish can have a significant impact on the populations of their prey species. By preying on a variety of fish and cephalopods, they can influence the population dynamics and the overall balance of the marine ecosystem. As apex predators, they play a crucial role in maintaining the health of oceanic food webs.