Quick Take
- The ocean sunfish looks like something that shouldn't exist, and its back end is the strangest part of all. See the strange anatomy →
- Scientists had one assumption about how sunfish behave in the ocean, but tracking data completely overturned it.
- The ocean sunfish was long considered the heavyweight champion of bony fish, a title it held until a close relative dethroned it. Explore the size records →
- Getting close to a fish this massive sounds terrifying, but there's a specific reason these swimmers weren't in danger while also having a reason they still needed to be careful. Find out about safety →
Most of us don’t think twice about pulling out a phone for a quick selfie. Doing it underwater with a giant ocean sunfish swimming a few feet away is another story. That’s exactly what happened to a group of swimmers off Cape Town, South Africa, who found themselves sharing the water with one of the strangest-looking fish in the ocean.
Ocean Sunfish Sighting in South Africa
The footage was captured off Cape Town by James Taylor while he was swimming with friends. Reports about the encounter described the enormous fish as an ocean sunfish, or Mola mola, and the group clearly wasn’t expecting their swim to turn into an underwater photo session.
At the beginning of the video, the swimmers are moving through the water when the massive sunfish comes into view. One of them lets out an excited squeal as the fish cruises nearby. Honestly, that’s probably a pretty reasonable reaction when something shaped like a swimming dinner plate suddenly appears next to you.
Taylor swims closer, and within seconds the group manages to turn toward the camera with the sunfish behind them. They eventually dip underwater and capture an even better shot with the enormous fish nearby. The sunfish seems remarkably calm throughout the encounter and continues moving through the water as its unexpected photo shoot unfolds.
How Big Are Ocean Sunfish?
Ocean sunfish feed heavily on jellies and other gelatinous animals, but their diet can also include squid, fish, crustaceans, and algae.
©Vladimir Wrangel/Shutterstock.com
The fish in the video looks enormous, but ocean sunfish can get much bigger. According to NOAA, the ocean sunfish (Mola mola) can approach 10 feet in length and weigh as much as roughly 4,800 pounds. Their huge, flattened bodies make them look even stranger because they don’t have the conventional tail most of us expect to see on a fish.
One distinction is worth making. Ocean sunfish have long been described as the world’s heaviest bony fish, but researchers now recognize the closely related giant sunfish (Mola alexandrini) as the record holder. Monterey Bay Aquarium notes that giant sunfish can exceed 6,000 pounds.
Sunfish also have an unusual structure called a clavus at the back of the body. Instead of a normal tail fin, the clavus forms a rounded, scalloped edge that works somewhat like a rudder. The fish generates most of its swimming power by moving its tall dorsal and anal fins from side to side.
Are Ocean Sunfish Aggressive Toward Humans?
Seeing a fish this large heading in your direction would understandably get your attention, but ocean sunfish are not known for being aggressive toward people. Smithsonian has even described Mola mola as an ocean “gentle giant.” Their diet is focused largely on jellies and other gelatinous prey, along with smaller fish, squid, and crustaceans.
Their awkward appearance can also be misleading. Scientists once thought sunfish were mostly sluggish drifters, but tagging research has shown that they are active swimmers capable of traveling long distances and diving hundreds of meters in search of food.
Of course, a calm animal is still a wild animal. Swimmers should give sunfish space, avoid touching or chasing them, and let the fish decide how close it wants to get. These swimmers happened to get one heck of a selfie out of their encounter, but the sunfish is still the one in charge of the photo shoot.
