Thursday, December 14, 2023

Dolphin With 'Thumbs' Stuns Experts In Historic Discovery


Marco Margaritoff
Wed, December 13, 2023

While many dolphins look alike, one particular specimen is sticking out like a sore thumb.

That’s what scientists at the Pelagos Cetacean Research Institute in Greece thought after spotting a dolphin with oddly deformed flippers that resemble human thumbs. According to LiveScience, the dolphin was observed in the Gulf of Corinth over the summer — twice.

“It was the very first time we saw this surprising flipper morphology in 30 years of surveys in the open sea and also in studies while monitoring all the stranded dolphins along the coasts of Greece,” Alexandros Frantzis, president of the institute, told the outlet Monday.

Frantzis added the dolphin was “swimming, leaping” and “playing” normally despite the “thumbs” and had no trouble keeping up with its pod. He believes the fins’ shape “does not look like illness” but stems from “rare and ‘irregular’ genes” as a result of inbreeding.

The 1,300 striped dolphins in the gulf are reportedly isolated from their Mediterranean peers and thus have limited options for breeding. According to the Marine Mammal Protected Areas Task Force, it’s the highest permanent striped dolphin species in the Mediterranean.

LiveScience noted that cetaceans, or marine mammals such as whales, dolphins and porpoises, naturally have phalanges. These finger bones are typically concealed by the tissue of their flippers, however, and not entirely missing — as seen in the Greek specimen.

The deformed flippers are currently being attributed to a genetic defect due to inbreeding.

“With a first rapid glance I thought it was injured,” Frantzis told HuffPost. “I immediately started shouting the news for the entire crew to focus on this dolphin and try not loosing it from our view. The dolphin went away from the bow, but we succeeded to approach it again and it came to bow-ride.”

Striped dolphins are some of the most abundant cetaceans in the world, according to the National Oceanic and Atmospheric Administration. They’re usually found in pods of 25 to 100 and have been observed jumping more than 20 feet above the surface of the water.

Their flippers are typically intact, however, unless mangled by predators or affected by disease.

“My surprise was huge when I realized then that both pectoral fins were not ‘normal,’” Frantzis told HuffPost. “I started spreading the news and effort went on for half an hour, because now we had to record this unique case photographically.”

“We got some first pictures of the flippers, which was great, but I was not totally satisfied,” he continued. “Fortunately, a few days later we met again the same school of dolphins and the same dolphin!”

The institute first reported its findings on YouTube in October. Fortunately for boaters around the world, these did not include any thumb-wielding orcas — yet.


'Unique' Dolphin with 'Thumbs' Spotted by Researchers in Greece in Rare Discovery

Bailey Richards
Tue, December 12, 2023 

"It is lovely to see that this animal is thriving," anatomy and neurobiology professor Lisa Noelle Cooper told Live Science of the striped dolphin


Alexandros Frantzis/Pelagos Cetacean Research Institute
Close up of the thumb-like flipper documented on a striped dolphin in the waters around Greece

A dolphin spotted off the coast of Greece stuck out from their pod like a sore thumb!

The striped dolphin, which has flippers that resemble thumbs, was spotted twice this summer in the Gulf of Corinth, Live Science reported.

The rare creature was spotted and photographed by researchers with the Pelagos Cetacean Research Institute (PCRI), a scientific non-profit focused on the study and conservation of cetaceans (whales, dolphins, and porpoises).

The PCRI first reported the sightings in October while sharing the results of recent boat surveys in a YouTube video.

“We recorded a unique striped dolphin with thumbs on both its pectoral fins,” the institute wrote in the video description.

Related: Casper the Rare White Dolphin — One of Only Three in the World— Appears in California

According to Alexandros Frantzis, the president of the PCRI who captured the photos of the rare dolphin, this was not only a "unique" sighting — it was something the institute had never seen before.

"It was the very first time we saw this surprising flipper morphology in 30 years of surveys in the open sea and also in studies while monitoring all the stranded dolphins along the coasts of Greece for 30 years," Frantzis told Live Science via email.


Alexandros Frantzis/Pelagos Cetacean Research Institute
Close-up photos of the thumb-like flippers documented on a striped dolphin by the Pelagos Cetacean Research Institute

Despite the creature's rare, thumb-like flippers — which "[do] not look like illness at all," per the researcher — it was able to keep up with the rest of their pod, "swimming, leaping, bow-riding [and] playing" with other dolphins, he said.

The Gulf of Corinth, the semi-enclosed inlet of the Ionian Sea, is the permanent home of about 1,300 striped dolphins who are isolated from the rest of the Mediterranean population, according to the Marine Mammal Protected Areas Task Force.

The dolphin's "thumb" flippers may be "the expression of some rare and 'irregular' genes" that arose because of interbreeding in the isolated dolphin population, Frantzis told Live Science.

Related: Football-Sized Goldfish Have Invaded the Great Lakes: They 'Eat Anything and Everything'

Lisa Noelle Cooper, an associate professor of anatomy and neurobiology at Northeast Ohio Medical University (NEOMED), also spoke with the outlet and agreed with Frantzis' theory that the thumb-like flippers are linked to the marine mammal's genetics.

"I've never seen a flipper of a cetacean that had this shape. Given that the defect is in both the left and right flippers, it is probably the result of an altered genetic program that sculpts the flipper during development as a calf," said Cooper, who studies mammal bone structure, per her NEOMED bio.

A stock photo of a striped dolphin

Whereas humans' fingers are fused into hands in the womb with cells that die off before birth, dolphins' flippers are formed by cells that accumulate around their forelimb bones, per Cooper.

"Normally, dolphins develop their fingers within the flipper, and no cells between the fingers die off," she told Live Science.

Related: Gray Whale Gives Birth in Front of Boats Filled with Amazed Onlookers in California — Watch!

Cooper said that the "hook-like" flipper formation observed in the unique dolphin from the Gulf of Corinth — where just the thumb and fourth finger remain — appears to be the result of missing tissue and missing finger bones.

"It looks to me like the cells that normally would have formed the equivalent of our index and middle fingers died off in a strange event when the flipper was forming while the calf was still in the womb," she told the outlet.

Of the creature's "thumb," she said it "may have some bone inside of it, but it certainly isn't mobile," noting that "no cetaceans have mobile thumbs."

Added Cooper: "It is lovely to see that this animal is thriving."

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