I found the photo at a Japanese tumblr called フリンジ削除 (link).
I'm quite confident it's not a creature of any sort. Perhaps a food item made by embedding something (?minnows) into gelatin inside a casing.
Followup: Solution pending! See Heavenlyjane's two comments.
I don't know what that is, but it's probably set in agar-agar and not gelatin, which may help you figure it out. Also, there is a drink called the Pissed Off Japanese Minnow Farmer. Thanks, Google!
ReplyDeleteMy first thought was some amphibian egg mass such as a toad or salamander whose eggs have hatched but the tadpoles have not yet emerged. I do not, however, have any evidence to back that up.
ReplyDeleteIt looks like an egg mass. I agree with Darren
ReplyDeleteI'm reminded of Dojo Jigoku, a Japanese dish in which baby Dojo fish are put into a frying pan full of oil. A block of cold tofu is then placed in the oil, and then you turn on the heat. As the oil gets hotter and hotter, the Dojo burrow their way into the cooler center of the tofu. But eventually, even the tofu is fried all the way through, and the Dojo are cooked inside. Not surprisingly, Jigoku means "hell."
ReplyDeleteBut that doesn't look like tofu. Maybe it could be what Claire said, agar-agar, and the same idea.
I think I've narrowed it down as a sausage jelly, which are egg masses produced by either Conical Sand Snails or Sordid Sand Snails. Here are a couple of links with photos:
ReplyDelete(1) Image #1
(2) Image #2
(3) Image #3
I think your photo shows the eggs as more developed.
Those are almost definitely tadpoles inside the "jelly". Some kind of amphibian egg mass that is about to release the offspring. Better get them closer to the water.
ReplyDeleteyes but do snail larvae look like little tadpoles?
ReplyDeleteGood question, Christine. I couldn't find any confirmatory images on a search. Apparently they are called "veligers"...
ReplyDeleteNot solved actually. I sent this image to Dr. Harasewych, curator of gastropods at the Smithsonian's National Museum of Natural History and he himself is baffled. He said it is definitely not an egg mass from Polinicies (conical or sordid sand snails). He is circulating it among Japanese colleagues to see if there are clues in the original Japanese website. More to follow, I hope.
ReplyDeleteI wrote to Dr. Bruno Pernet, a mollusc-focused marine biologist at Cal State Long Beach, and he reported the following:
ReplyDelete" I'm assuming the elongate, dark things in the jelly are embryos. If so, I would argue that this is not mollusc or annelid; they look kind of fishy to me! I don't know of any fish that lays embryos in gelatinous masses like that, but I don't know much about fishes.
Sorry, that's all I've got. I've never seen anything like that before. "
Will change focus of search to icthyology, and from there to Japanese food culture.
Thank you, Conor, for service over and above the call of duty.
ReplyDeleteI'm forwarding to a marine biologist cousin, as well.
Dr. Woollacott of Harvard University agrees with Dr. Harasewych, but offers no further insight.
ReplyDeleteDr. Kohn of the University of Washington adds the following:
"Jerry Harsewych is right, in fact it's not molluscan and certainly not Conus! It appears to be an egg mass containing tadpole larvae. As far as I can tell they have only forelegs, suggesting that they are likely salamander. It could be the Japanese giant salamander Andrias, that may reach 5' in length, but I don't know what its eggs are like."
The hunt continues.
Prompted by the comments above, I did some additional searching and found this re the Dunn's salamander in Japan:
ReplyDelete"At deposition, these eggsacs are still small. They absorb water during the first days and actually become larger than the female. According to the literature, the egg masses of Hynobius dunni typically measure between 15 and 30 cm (6-12 inches)... After a few days, the outside layer of the eggsacs becomes a quite tough and elastic. This might deliver a certain degree of protection against eventual dehydration and certain predators, such as Planaria...
As the larvae near hatching, the outer membrane of the eggsac seems to become less tough. Inside the eggsacs, the larvae hatch from their individual eggs, then they appear to be trapped inside the egg sac. After a while, the rear end of the eggsac opens, and the larvae swim or fall out..."
More at this link, including photos:
http://www.caudata.org/cc/species/Hynobius/H_dunni.shtml