Large New Whale Species Identified in the Gulf of Mexico

Named Rice’s whale, the species can reach lengths of 42 feet and lives in the Gulf’s warm waters all year

Stranded Rice's whale
A 38-foot male whale washed up along Sandy Key in the Florida Everglades in January 2019. Researchers have now determined that the whale is a member of a previously unknown species they've dubbed Rice's whale. A necropsy revealed a 3-inch hunk of plastic lodged in its gut that may have contributed to its demise. NOAA / Florida Fish and Wildlife Commission

In 2019, a 38-foot baleen whale washed up near the Florida everglades, but now researchers suspect the individual may belong to a brand new species—Rice’s whale (Balaenoptera ricei)—that calls the Gulf of Mexico home, reports Zachary T. Sampson for the Tampa Bay Times.

A study detailing the discovery of Rice’s whale, published last month in the journal Marine Mammal Science, suggests there may be fewer than 100 of the new species left in the wild, instantly adding the species to the list of critically endangered species, according to a statement from the National Oceanic and Atmospheric Administration.

Dale Rice, a marine mammal scientist with a storied 60-year career, is the new species’ namesake. Rice recognized that a small population of whales was living in the northeastern part of the Gulf of Mexico year-round in the 1990s. But at the time, the assumption was that these were a sub-population of Bryde’s whales, reports Greg Allen for NPR.

In 2008, NOAA scientists conducted a genetic analysis of tissue samples from the mysterious Gulf population. That analysis suggested the population was genetically distinct from other Bryde’s whales, reports Michael Marshall of New Scientist.

“But we didn’t have a skull,” Patricia Rosel, a geneticist at the NOAA Southeast Fisheries Science Center and lead author of the paper, tells New Scientist. A skull, Rosel says, is essential to establishing a new species of whale.

When a fisher spotted a 38-foot carcass near Sandy Key in 2019, measurements and other data from the necropsy suggested it was worth a closer look.

"Through some really enormous efforts of the stranding network to respond to that dead whale...and save it and preserve it, we were finally able to look at the skull morphology and make comparisons to those other Bryde's whales," Rosel tells NPR.

Large New Whale Species Identified in the Gulf of Mexico
NOAA's Patricia Rosel examines the skull of what is now officially Rice's whale in the collections of the Smithsonian National Museum of Natural History. NOAA

To clean the massive skeleton for study, NOAA scientists and members of the Marine Mammal Stranding Network buried it underground at Fort De Soto Park for several months, and finally unearthed the bones and shipped them to the Smithsonian’s National Museum of Natural History where Rosel and others were able to study the specimen in detail.

The skull revealed tell-tale anatomical divergences from Bryde’s whale, in particular, bones atop the skull surrounding the animal’s blowhole, according to the Tampa Bay Times.

Chris Ciaccia of Live Science reports the newly minted Rice's whale can weigh up to 60,000 pounds and reach lengths of 42 feet. That’s a bit smaller than Bryde's whales, which can exceed 50 feet. Researchers estimate the new species can live to around 60 years old, but more data is needed to confidently establish a maximum age.

“Even something as large as a whale can be out there and be really different from all the whales, and we don’t even know it,” Rosel tells the Tampa Bay Times. “It really brings to light the urgent need of conserving and protecting these animals in the gulf, and making sure we don’t lose another marine mammal species like we already have.”