Proof of ‘gigantism’ found by deep sea explorers off southern US: A huge shrimp

Giant Acanthephyra caught between 3,937 and 4,921 feet down during a NOAA expedition of the southeastern U.S.
Giant Acanthephyra caught between 3,937 and 4,921 feet down during a NOAA expedition of the southeastern U.S. NOAA Ocean Explorer photo

A “giant” shrimp longer than a human hand was encountered Sunday as part of an expedition to collect data “about unknown and poorly understood deep water areas” in the Gulf of Mexico.

Deep sea explorers, who were clearly impressed, cited the blood-red creature as an example of “the phenomenon of gigantism in the deep sea, when animals grow much larger than their shallow water relatives.”

The expedition, supported by the National Oceanic and Atmospheric Administration, posted photos of the discovery Monday, including one showing the normal size for such shrimp is about the length of a fingernail.

“Normal” shrimp from the twilight zone and “giant” shrimp from the midnight zone. NOAA Ocean Explorer photo

The giant shrimp was found between 3,937 and 4,921 feet down, during a mission ominously called “Journey into Midnight: Light and Life Below the Twilight Zone.” The expedition is being funded by NOAA, and is led by scientists from a wide range of institutions and organizations.

“Gigantism in animals is found exclusively” in ocean waters below 3,280 feet — an area known as the “midnight zone,” said expedition member Tamara Frank, of Halmos College of Natural Sciences and Oceanography at Nova Southeastern University.

Among her explanations is one that suggests even bigger shrimp could be out there, waiting to be found.

“Probably one of the most important reasons, is that they have indeterminate growth, meaning that there is no set size at which they stop growing like in humans – as long as they get enough food, and aren’t eaten, they just keep growing and growing,” Frank wrote in a post on the NOAA Ocean Exploration and Research site.

One reason they keep growing could be fewer predators in the deepest parts of the ocean, she wrote.

“However, with a large size comes the drawback of needing more food, and while there are fewer predators below 1,000 meters, there are also fewer prey,” she says.

“You run the risk of starving to death because you cannot find enough food to feed your growing body. That is why the deep sea is not filled with huge shrimp, giant squid are few and far between, and jellyfish the size of cars have only rarely been seen.”

The expedition continues through June 22, focused on “the water column in some of the deepest parts of the Gulf of Mexico,” says NOAA. Among its goals is to see the impact darkness has on deep sea animals, officials said.

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