Orcas specialize in hunting the largest fish in the world in packs

Nov 29. () –

A total of four hunting events, where orcas hunted the world’s largest fish, the whale shark, have been documented by scientists in waters of the Gulf of California.

In coordinated attacks, the orcas targeted the sharks’ pelvic areas, which caused them to bleed out and gave them access to the liver. The behavior of orcas in this way could mean that there is a specialized pod of hunters in the Gulf of California, the researchers conclude.

Orcas can feed on marine mammals, turtles and fish. In the Gulf of California, a pod may have acquired new skills to help them hunt whale sharks, the world’s largest fish. which grows up to 18 meters long.

Whale sharks feed at aggregation sites in the Gulf of California, sometimes while they are still young and smaller. During this stage of life, they are most vulnerable to predation, and anecdotal evidence suggests that orcas could be hunting them. Now, researchers in Mexico have reported four separate hunting events.

“We show how the orcas deployed a collaborative hunting technique for whale sharkscharacterized by focusing on attacking the pelvic area, causing the whale shark to bleed to death and allowing the orcas to access the lipid-rich liver,” he said. in a statement Erick Higuera Rivas, marine biologist at Conexiones Terramar and main author of the article, published in Frontiers in Marine Science. “One individual participated in three of the four events, along with other members who could belong to a pack specialized in hunting sharks“.

The predation events occurred between 2018 and 2024 in the southern Gulf of California and were captured in images and videos taken by members of the public and scientists. Individual killer whales were identified by analyzing photographs of their dorsal fins and distinctive features such as scars.

A male orca named Moctezuma was present in three of the four hunting events.. A female orca previously observed in Moctezuma’s presence also participated in an event, suggesting they could be related or members of the same pod.

“When hunting, all members of the pod work together, striking the whale shark to turn it over. In that position, the sharks enter a state of tonic immobility and can no longer move voluntarily or escape by going deeper,” explained Higuera Rivas. “By keeping it under control, the orcas have greater ease and speed in approaching the shark’s pelvic area.” and can extract organs of nutritional importance to them.

The orcas may be targeting the ventral side of the whale sharks because their bodies are thought to be less protected there. For example, there is less muscle and cartilage in this area, allowing easier access to the aorta. Although whale shark livers are an important part of the orca diet, there was no photographic observation of the orcas consuming the organ.

SPECIAL SKILLS

Hunting this way could mean that some orcas in the Gulf of California have acquired special abilities that help them hunt whale sharks. In other regions, orcas may have learned to do the same, but the evidence is limitedthe researchers said.

Gathering the data the scientists needed was not easy. Attacks cannot be predicted, access to images and videos may be limited, and image quality is often too low to reliably identify animals.

Despite this, the researchers said their finding could have several implications. The fact that there is a whale shark hunting pod in the Gulf of California the need to manage marine adventurers and tourists increases, the researchers warned. “There must be a specific regulatory standard that guarantees that any type of non-extractive use activity is carried out in a respectful and sustainable manner,” said Higuera Rivas.

Furthermore, if the thesis is supported that Moctezuma and his pod have acquired ecological and behavioral information to hunt whale sharks in the Gulf of California, the pod could be vulnerable to a possible disappearance of this specific prey due to climate change in the region. .

Ultimately, new information related to these killer whales helps researchers better understand their unique adaptations to their needs and geographic location. “It’s very impressive how the orcas work together strategically and intelligently to access only a very specific area of ​​the prey. This highlights how big predators they are.“, concluded Higuera Rivas.