Many sharks bear live young (viviparous or ovoviviparous), while some deposit egg cases (oviparous).
Pictured here are two eggs cases belonging to a blotchy swell shark (Cephaloscyllium umbratile) or nanuka-zame (ナヌカザメ) in Japanese.
It’s basically a catshark that can puff itself up as a means of self-defence.
I haven’t seen any of these sharks, but we found these two egg cases relatively deep, at about 23 metres…where white against a primarily brown background was a dead giveaway. Having them deposited so closely together is rare according to my dive guides.
The eggs are relatively new, and it takes about 10 months for the babies to mature and hatch…which means that these egg cases should be around until early next year. Within a short time, all the guides in the area will know about these eggs, so a lot of divers will have the opportunity to see and photograph them (plus keep an eye on them).
If I get a chance to visit again during the interim, I’ll make a point of checking again to see how these young sharks progress.
Forgot to mention that these egg cases are called mermaids’ purses here…ningyo no saifu (人魚の財布)
Very pretty egg cases. An artistic piece in itself.
very nice, we have lots of swell sharks here in california. The sharks are usually in small caves / crevices during the day and come out at night. we call them mermaid’s purses too. Try backlighting the eggs, they look great like that!
Thanks Karenne!
Scott: I though about it, but the eggs are still fresh, so there’s nothing much to see yet. Perhaps when they grow up a bit, if I get another opportunity. I’ll have to look for the adults too. And thanks for letting me know re: mermaids’ purses. Interesting that it’s the same in two languages.