You're familiar with beluga whales, blue whales, humpback whales and killer whales, but have you ever heard of Omura's whales? That's OK. Scientists hadn't heard of them either until 2003, and the species has eluded close study until just this year.

A Woods Hole Oceanographic Institution release from October 22 details a new study on the whales and their behavior. It describes them as "one of the least known species of whales in the world."

Even for people who aren't marine biologists, these whales represent a fascinating piece of the ocean ecology puzzle. We're all familiar with the Save the Whales movement. Research on Omuar's whales will tell us how rare the species is and whether it needs to be the focus of conservation efforts.

Salvatore Cerchio

"This is the first definitive evidence and detailed descriptions of Omura's whales in the wild and part of what makes this work particularly exciting," says Salvatore Cerchio, the study's lead author. The paper appeared in the Royal Society Open Science journal earlier this month.

Omura's whales were originally mistaken as Bryde's whales until genetic testing in 2003 determined they're a separate species. They live off the coast of Madagascar and look slightly different than the better-known Bryde's whales. They're a little smaller and have jaw markings that are dark on the left side and white on the right.

Cerchio and a team of researchers spent two years observing the whales and their calves, recording their vocalizations and gathering skin biopsies for DNA analysis. The DNA work confirmed the species and photographic cataloging identified 25 individual whales.

Omura's whales can reach up to 38 feet (11.5 meters) in length, which is quite small when compared with larger species like blue whales, which can reach up to 100 feet (30 meters). That size makes them challenging to track in the wild. A new round of studies is planned for later this year to learn more about the whales' vocalizations, behavior and population size.

Omura's whales aren't the only surprising species to pop up on scientists' radars recently. Researchers identified a new species of Galapagos giant tortoise that had been hiding in plain sight, much like these whales. It shows how even well-studied corners of the globe can still offer up biological mysteries.