Scientists examine a newly hatched dumbo octopus
With their big fins Dumbo octopods (Grimpoteuthis) remind of the giant ears of Disney's elephant of the same name. Researchers were now able to observe how such an animal hatched from the egg.
During an expedition to explore a chain of underwater mountains off the US East Coast, researchers had the opportunity to observe and film a dumbo octopus just hatching from the egg. The results of her research have now been published in the journal Current Biology.
"It was the first time that such a deep-sea octopus was observed directly during hatching," says Liz Shea of the Delaware Museum of Natural History and lead author of the study, which included scientists from the University of Bonn, the University Hospital Münster, and the Woods Hole Oceanographic Institution (WHOI).
The octopus egg, which was attached to a cold water canal branch, was brought aboard the US research vessel "Ronald H. Brown". At coral branch, a female had apparently attached her egg sheaths. A remote-controlled vehicle collected the coral sample at a depth of almost 2,000 meters.
"It was a unique observation, a turning point that sheds light on a completely unknown part of the life cycle of Dumbo octopods in the deep sea," said Tim Shank, deep-sea biologist at WHOI and co-author of the study.
After the researchers placed the small squid in a container of seawater after hatching, the researchers were surprised when they saw that the animal immediately began to move its fins synchronously.
"As the video by Dr. Shank shows, the Dumbo Octopus behaves like an adult animal, which is about ten times bigger," explains co-author Alexander Ziegler from the Institute for Evolutionary Biology and Ecology at the University of Bonn.
To find out more about this rare specimen, members of the research team at the University Hospital Münster have taken a look inside with a high-resolution magnetic resonance tomograph. Using MRI images, the researchers created an interactive three-dimensional model of the inner organs of the small deep-sea octopus.
"Especially striking was a large yolk sac, which serves as a nutrient source directly after hatching, until the young can independently catch tiny crustaceans in the deep sea," explains Dr. Ziegler.
Due to the size and shape of the internal organs of the rare specimen of the Dumbo octopus genus Grimpoteuthis could be assigned. "Unfortunately, it was not possible to determine the species, because egg and juvenile can belong to a species that is still unknown to science," says Shea.
The scientists urge that their study stresses the importance of protecting this sensitive deep-sea habitat, which is still largely unexplored. Trawling and Tiedsee mining endanger the habitat of deep-sea corals and all organisms associated with them.
Link to the study: www.cell.com/current-biology/fulltext/S0960-9822(18)30034-4