MRI and CT scan tech used to nondestructively classify "new" octopus
Ordinarily, if biologists wish to confirm that an animal specimen represents a new species, they have to perform a dissection – essentially destroying it. Now, though, the task has been accomplished non-invasively, using MRI and CT scan technologies.
Back in 2016, scientists from Germany's University of Bonn discovered what they thought could be a new species of dumbo octopus, so-named because of the fins on its head that look like elephant ears.
Measuring about 30 cm long (12 in), the creature was captured in a steel basket on the seabed of the North Pacific Ocean, and was then winched 4,000 meters (13,123 ft) up to a research vessel on the surface. Unfortunately, due to the relatively sudden change in water pressure, the octopus died upon reaching the ship.
Because they only had the one valuable specimen, the scientists wanted to keep it intact – but they also wanted to look inside of it, to see if it really was a previously unknown species. In a recently published paper, lead scientist Dr. Alexander Ziegler describes how they went about doing so.
In an initial MRI (magnetic resonance imaging) scan, the creature's internal organs and other soft tissues were successfully revealed in a series of high-resolution 3D images. Due to the fact that its beak and rasping tongue were made of a hard substance known as chitin, however, they didn't show up very well. This problem was remedied by performing micro-CT (computed tomography) scans, which are better for imaging hard materials.
Additionally, the animal's DNA was sequenced from a tissue sample that was taken when it was captured.
When all the data was analyzed, it was determined that the adult male specimen did indeed represent a new species of dumbo octopus. The creature has been named Grimpoteuthis imperator, which is Latin for "Emperor dumbo" – it was captured near Japan on an underwater mountain range, the peaks of which are named after Japanese emperors.
Because the specimen is still in one piece, it can now be examined by other biologists who might otherwise have to collect and kill additional octopi. What's more, a "crisp digital copy" of the specimen can be downloaded from the online MorphoBank database.
"Our non-destructive approach could set a precedent, especially for rare and valuable animals," says Ziegler.
A paper on the research, which was co-authored by PhD student Christina Sagorny, has been published in the journal BMC Biology.