Raja Binoculata egg casings, wow they are big!!

[Gill Envy]

After all these years and I've never stumbled upon an Raja Binoculata egg casing, the egg casing of a skate comonly known as the big skate which grows up to 6 ft. Did a dive in Mukulteo with a friend today and found the sea floor littered with them. If you have never seen one, they are huge. the first thought that went through my head was, holly cow, the thing that laid this was huge. It was twice the size of the egg casings of the nurse sharks we saw in an indonesian cave, and those sharks were 12 footers! When I got home I looked it up and was surprised to learn it was a skate, would have figured it was a mamoth shark. the casing stretched the better length of my forearm!! When I read up on the skate, it ws mentioned that they have remarkably large egg casings, so maybe this isn't such a big deal, accept that there were a couple of dozen of them and I'd never seen one before. They were mostly hatched, but a few were still gestating with little embryo's inside, which we gently candled with our dive lights... the egg casings are particularly cool because they have a very interesting angular, boxy look. it was a cool dive, just had to share it.

g

[BASSMAN]

What? No pictures?

[4ster]

We didn't bring a camera, darn it. Gill looked it up... here is a link:
http://www.arkive.org/big-skate/raja-bi ... 49807.html

Steve

[BASSMAN]

Okay so here's a question...

Why is it called a Big "Skate" and not a "Pacific North West Stingray"?

[smike]

How deep were you when you found them? I found a few earlier this year, in the 80 -100 fsw range. They were not hatched, and the young were not big enough to have a shape. I would love to get down there and see one with the embryo moving. There are pictures I took at this thread:

http://www.nwdiveclub.com/viewtopic.php?f=11&t=7267

S'Mike

[4ster]

About 115 - 130.

[smike]

I'm heading down there later today, to see the troll - Hope to find some then!

[gcbryan]

Okay so here's a question...

Why is it called a Big "Skate" and not a "Pacific North West Stingray"?

Because it's not a ray...no barb.

[gcbryan]

After all these years and I've never stumbled upon an Raja Binoculata egg casing, the egg casing of a skate comonly known as the big skate which grows up to 6 ft. Did a dive in Mukulteo with a friend today and found the sea floor littered with them. If you have never seen one, they are huge. the first thought that went through my head was, holly cow, the thing that laid this was huge. It was twice the size of the egg casings of the nurse sharks we saw in an indonesian cave, and those sharks were 12 footers! When I got home I looked it up and was surprised to learn it was a skate, would have figured it was a mamoth shark. the casing stretched the better length of my forearm!! When I read up on the skate, it ws mentioned that they have remarkably large egg casings, so maybe this isn't such a big deal, accept that there were a couple of dozen of them and I'd never seen one before. They were mostly hatched, but a few were still gestating with little embryo's inside, which we gently candled with our dive lights... the egg casings are particularly cool because they have a very interesting angular, boxy look. it was a cool dive, just had to share it.

g

The aquarium (SEA) had some on display. They removed the top portion of the casing and replaced it with clear plastic. You could see the embryo's moving and see the egg yolk like "thing" that they are attached to for nutrients.

[Gill Envy]

a marine biologist friend who works at one of the aquariums just sent me some info: the egg casings hold 4-12 developing embryos in each, that's why they are so big. He and his co-workers ultrasounded a couple of them and noticed that for a period, the developing gills are actually outside the body and look really bizarre.

on the dive we had some bright lights and could make out the embryo of one, it would be cool to be able to see through that window you are talking about. the casing is pretty thick so it wasn't super clear but still cool to see. turns out there are multiple eggs in each casing typically, which partly accounts for why they are so big... the dimensions of the biggest one was something like 11'' x 5'' x 4'' and looked like something from outer space. It's still hard to believe a skate can lay something that large, I imagine the skate that laid the largest one was of mammoth proportions. I've have seen a juvenile Big skate, but no where near 6' long. I was not aware we had such a large beast here in the sound.

the eggs where located directly out from the parking area next to the silver cloud Inn, we were in the 140 ish range when we saw the live one but I bet there are some live ones a bit shallower. I mention the location with a little bit of reservation, please respect these amazing creatures if you see one and be gentle with the eggs!!