Researchers who explore the ocean are privy to a lot of interesting things that the layperson is not. They routinely see things that are incredibly fascinating, but even they’re surprised sometimes. Such was the case in 2018, when scientists found an embryonic cat shark in its egg case.
“This is extremely rare,” one of them said. “To actually see one of these egg cases with the shark inside.”
The cute little shark was spotted during the Océano Profundo 2018 expedition, which took place along the Pichincho Wall at depth ranges of 820-1,200 feet. It’s a poorly understood deepwater area surrounding Puerto Rico and the U.S. Virgin Islands.
Cat sharks are an oviparous species, meaning they lay their eggs outside the mother’s body. The pups are then left to fend for themselves. The yolk sac that’s visible in the egg case gives the growing animal all the nutrients it needs to develop, and the sacs can be attached to algae, like in the video above, or even on invertebrates. As soon as the shark pup reaches a certain stage of its development, it’s ready to swim and begin life outside the egg sac.
“While we’d seen these cases on previous expedition dives, they had all been empty,” the researchers wrote. “The fact that we saw this one, alive and directly linked to a coral colony, tells us a lot about how important deep-sea corals are as nursery habitats for fishes and other organisms.”
