Two Large-Mouthed Sharks Spotted on San Diego Shoreline for the First Time

SAN DIEGO – A pair bigmouth shark (Megachasma pelagios) which is very elusive appears and swims together off the coast of San Diego, United States of America (US). Only five megamouth sharks have been seen swimming freely in the wild and a pair has never been seen swimming together.

This pair of sharks appearing together may indicate courtship rituals prior to entering the mating season. In the 50 years since the species was discovered, there have been only 273 sightings, most involving sharks caught in fishing gear.

Sightings of a pair of bigmouth sharks were recorded by local fishermen in early September 2022. A new study analyzing the footage shows that the two sharks engaged in courtship or mating behavior.

“The curiosity of the fishermen is profitable to get information from the field as a whole. The 10 minutes of footage from the fishermen is the only information about the bigmouth shark,” Zachary Skelton, a graduate student at the University of California, San Diego, told Live Science, Saturday (25/3/2023).

To better understand the megamouth shark’s behavior, Skelton and colleagues analyzed footage based on it. They also studied the literature on the social behavior of other filter-feeding sharks, such as the basking shark (Cetorhinus maximus) and the whale shark (Rhincodon typus).

“Because the encounter was so brief, we had to rely heavily on research and other species to try to understand why the sharks were on the surface, why they were together and why in that particular place,” said Skelton.

The elusive bigmouth shark can grow up to 5.5 meters long and weigh up to 1215 kilograms. This round-headed creature is a filter feeder that is caught in its large mouth.