A shark that survived being bitten in the head by a marlin

A blue shark had its head skewered by a swordfish, but lived to tell the tale, as the first known example of a shark surviving this type of skewering.

When the shark was captured by fishermen in Vlore, southern Albania, it had no new bite wounds and had food in its stomach, indicating it was feeding normally. A subsequent autopsy revealed a 18.6-centimeter fragment of the swordfish’s beak embedded in the skull.

“I was surprised when I noticed that there was a marlin’s beak inside the shark’s head,” says Andrei Gadzic from the Shark Club ADRIA Research Center in Vlore.

Gadzic has performed tens of thousands of shark dissections. “I’ve never encountered anything like this before, nor have I read about it in the literature,” he says. His team tried to revive and release the bycatch shark if possible, but the shark died before reaching the port.

To date, eight occurrences of blue sharks have been recorded (glaucoma) skewered by a marlin (Xiphias Gladius) A swordfish rostrum was found in or near the shark’s head. Bigeye shark (Allopias supersiliosus) and mako shark (Isurus Oxyrhynchus) Bites have also been found by billfish, a group that includes swordfish.

This is the first time a shark has been confirmed alive in such an encounter. The juvenile marlin likely reacted instinctively by lifting its head and snapping off its beak without damaging the shark’s vital structures, Gadzic said.

The adult shark was 275 centimeters long and weighed 44 kilograms. The marlin can reach a maximum length of about 455 centimeters and a weight of 650 kilograms. There have been some reports of blue sharks feeding on marlin tuna, and both animals use aggressive hunting tactics to feed on dense schools of fish and squid.

Such punctures can occur when a swordfish attempts to defend itself from a blue shark attack, or by an accidental collision when both predators are feeding on the same prey. Gajic said further observations are needed to determine the cause.