According to a popular Disney princess, "flipping your fins, you don’t get too far"–unless, of course, you happen to be a Dumbo octopus. Thanks to their giant fins, these marine creatures bear a striking resemblance to the floppy-eared Disney elephant, and, unlike Ariel the mermaid, they successfully navigate the seafloor while flapping their floppy fins.
Scientists’ understanding of the Dumbo octopus is relatively limited, but a new study in Current Biology sheds some light on the deep sea dwellers, detailing the first observations of dumbo octopus hatchlings. The biggest takeaway? Newly hatched Dumbo octopuses are nearly identical to their adult counterparts, which means their trademark fins are present from the very beginning.
As Newsweek’s Kristin Hugo reports, the team’s findings are significant because dumbo octopuses, or creatures in the genus Grimpoteuthis, are incredibly difficult to study. They live on the bottom of the seafloor (as deep as 13,000 feet below sea level). And even when scientists dive that deep, they typically can't find octopus eggs, which the adults hide on bits of coral.
“If an egg is able to be disguised long enough, then it has a better chance of surviving to adulthood without being eaten,” Elizabeth Shea, curator of mollusks at the Delaware Museum of Natural History and lead author of the new study, tells Hugo.
The team's rare specimen dates back to 2005, when Tim Shank, marine biologist at the Woods Hole Oceanographic Institution and author of the new study, led a research cruise that used remotely operated vehicles to explore the Northwest Atlantic. According to a press release, he noticed tan, golf ball-like masses stuck on coral branches and decided to collect several samples.
After realizing that the specimen was a type of egg casing, Shank deposited the coral into a five-gallon bucket. Soon, the egg case opened, and a hatchling emerged.
“Once the fins were observed while [the hatchling] was still in the bucket, it was clear that it was a 'dumbo' octopod,” Shea says in a statement.
Scientists observed the hatchling for about two hours and recorded a short video of it swimming around a petri dish.
Later, the research team measured the specimen and examined its anatomy with magnetic resonance imaging. As Live Science’s Brandon Specktor reports, the hatchling’s mantle, or casing that contains most of its internal organs, is tiny, measuring just a half inch across. Despite its small size, tests showed that the octopus was born fully formed.
Specktor writes, “[It had] everything it needed to immediately swim with its fins, sense its environment and capture prey (which Dumbo octopi swallow whole). It was even born with a large internal yolk sac, researchers said, which contained enough nutrients to keep the hatchling alive for several days while it learned to catch its first meal.”
The MRI scans, as well as an accompanying 3-D reconstruction of the hatchling, allowed scientists to better understand the octopus’ complex central nervous system and led them to their overall conclusion: Dumbo octopuses hatch as competent juveniles.
“From a biological perspective, this is kind of connecting the dots in an otherwise somewhat poorly understood group of organisms,” Shea tells Hugo.