Any ideas on ID? Pelagic species from 2000 NOAA trawl

OB · Apr 01, '07, 4:50am

This one from the Bering Sea has been puzzling me for some time...

"Scientists are uncertain of the specific identity of this rarely caught pelagic Octopod. The yellow ring occurs only in females and is thought to be commonly eaten by Dalls' Porpoise. They are rarely ever caught in standard survey trawls."

**tonmo** · Apr 01, '07, 9:09am

Originally Posted by ob

The yellow ring occurs only in females

weird.

**Clem** · Apr 01, '07, 9:21am

Function of the yellow ring presumably related to mating and/or the brooding cycle, however Blaauw conjectures that the ring allows the octopus to play both 45s and standard LPs.

**cuttlegirl** · Apr 01, '07, 10:16am

I found a reference to the family Bolitaenidae.
http://www.environment.gov.au/cgi-bi...hecklistMode=2

The pelagic octopods of this family have gelatinous bodies, with arms shorter than the mantle. The arms are equipped with a single row of suckers and are connected by a web of moderate depth. The mantle is oval with the aperture wide. Adult females have a luminous organ in the form of a thick ring under the integument around the mouth. The radula is comb-like. Males lack a hectocotylus.

Will search some more...

Here you go - http://tolweb.org/Bolitaenidae/20193

Your photo looks like Japetella diaphana

**Clem** · Apr 01, '07, 10:28am

Cuttlegirl, looks like you nailed it. Good job!

OB · Apr 01, '07, 11:18am

Hear, hear!!!! Japetella diaphana

PS: Adam, that is SO funny

**Steve O'Shea** · Apr 01, '07, 2:16pm

I've never seen such a large one! Most peculiar indeed (we get the pelagic juveniles here (NZ), but they're certanly not common).

**main_board** · Apr 01, '07, 6:43pm

The ID seems to be definitive. Good job cuttlegirl! I was thinking the same thing as Steve, though. TolWeb says they're small octopods, with the largest specimen being 85 mm ML. Now it's difficult to get much in that image for a size reference, but I was thinking that that orange thing top right was a glove of some sort. That would make this a considerably bigger specimen. But I'm not really sure.
Thanks for posting this. Its a really cool species that I hadn't a clue about!

Cheers!

OB · Apr 02, '07, 2:46am

The arms in the specimen held in the pic above appear to be around 150 mm or so and tolweb states that the arms are "considerably shorter" than the mantle; a fact collaborated by the photographs of young specimens included in the entry. Now if a 150 mm + mantle would be hiding underneath the arms in the palm of that gloved hand, I'd be surprised. I'd be a lot less surprised if it turned out that the arm mantle ratio changes over time, with the arms getting longer towards maturity. This appears to be the case in many cephalopods, so why not this one?