Gonatopsis

[GPO87]

Gonatopsis is noteworthy because as an adult, it lacks tentacles.


SEE! I even have proof!

Although, this really isn't all that unique, as members of Octopoteuthidae also have lost their tentacles....

Info at:
http://tolweb.org/Gonatopsis/19764

 

[Heather Braid]

Don't forget that every single Mastigo specimen that I have is also lacking tentacles. Of course, it's only because of their poor construction so they get pulled off. Gonatopsis sure is adorable in paralarval form!

 

[DWhatley]

Is that starlike formation around the beak an artifact of preservation/dissection or is that a notable construct of the animal?

 

[OB]

You are likely referring to the buccal crown, present in most squid species, but lacking in Octopus?

 

[OB]

It will actually cover the buccal mass, when called for, as seen here in Dosidicus.

 

[DWhatley]

It is the starfish looking arrangement around what I understand to be the buccal mass that I have not noticed before. It may be that I just have not seen it opened like that since I mostly see live animals and don't really look much at the dead one

 

[GPO87]

Is it not present on octopus? I didn't know that, OB! Cool fact of the day!

 

[DWhatley]

There is a buccal mass but not that starfish looking shape around it (either open or closed as in the Humboldt). I was sure I had not seen it before but then looked at my monitor's wallpaper - no starfish shape on O. briareus, just suckers in a circle around the not exposed beak. Then thinking about it, I am sure I have never see anything like that in the flesh, even with beak exposed so I would say from observation and personal photos the little guys we keep normally don't have it or it is very, very small and hidden behind the tiny suckers that encircle the beak area.

This is LittleBit (probably small vulgaris) all the ones I have for briareus show food in the way but it is the same as with hummelincki

 

[jeffday]

here's gonatopsis brooding eggs in the gulf of california. there was some back and forth over what genus of gonatid this was - mike v thought it was gonatopsis borealis but dick young wasn't totally sold on that identification, last i heard. pretty sure this is the only observation of gonatopsis with eggs.

 

[tonmo]

great shot! honestly thought I had seen this species brooding before. I will try to dig.

 

[tonmo]

This?

https://www.journals.uchicago.edu/doi/pdfplus/10.1086/BBLv223n3p259

from here:

Gonatus

These members of Gonatidae have one or more medial hooks on their tentacle club. They are also known for brooding masses of eggs in their arms. Gonatus brooding eggs Tentacle club of Gonatus californiensis Info at: http://tolweb.org/Gonatus/19767

tonmo.com

 

[tonmo]

oh! different species! thanks @jeffday for that pic -- unique!

 

[jeffday]

two species of gonatus have been observed brooding, one of them multiple times (onyx), but gonatopsis hasn't been observed aside from this instance.