The ocean is a mysterious place. While the ocean covers 70% of our planet, we have only discovered 5% of it leaving us with many questions. Questions like, “What on Earth are these spiral thingies that keep washing up onshore?”
During the spring and summer, horn sharks lay two egg cases every 10-14 days with one embryo in each case. The cases are made of material that are similar to fingernails or hair and it forms around the fertilized egg inside of the mother in the oviducal gland.
According to Christopher Lowe, the marine biology professor who runs the Shark Lab at California State University, Long Beach, they really aren’t sure why the egg case has its spiral shape. “It’s unclear how that shape actually develops.” but his guess is that the gland inside of the shark is twisted so the egg case takes its shape.
After the eggs are laid, the mother doesn’t stick around. She leaves the embryo in a safe place and the embryo lives off of a yolk sac inside. “The mom basically packs a little lunchbox full of nutrients that the developing embryo will grow off of,” says Lowe.
The spiral shape helps the egg sac stay put in the ocean. It allows it to get a good grip amongst the rocks and other sea life where the mom lays it down. Lowe explains, “It wedges into a rock really well, so that if there’s surge and waves, it won’t move the egg, and it makes it harder for predators to get it.”
Eventually algae will grow on the egg case to help camouflage it and keep it safe from predators. A common predator is the sea snail called the whelk. Using their mouth, they can drill a hole into the egg case and eat the yolk.
Although mom bailed on them, the female sharks will lay eggs where they know that there is food, like small shrimp and crabs that the baby horn shark will be able to easily find.
13. The More You Know
So next time you see one of these little suckers, remember that it once housed a little baby shark that is now exploring the ocean, eating shrimp and crabs and living his life. For more information about horn sharks, check out this video!