Hello Cephalopod lovers,

I teach marine science a the Dauphin Island Sea Lab in Alabama, USA. Presently, through my door I hear 2 of my collogues dissecting squid. My question is ... In all female squid, are the large thick white organs the nidamental glands, anterior to the egg mass, and egg mass the correct term for the gelatineous structure holding the eggs? If so, what is the reddish/pink organ/structure connected and associated, generally on the anterior end of the nidamental gland? Which of these organs is actually the ovary and are cephalopods the only animals which possess a nidamental gland? Thanks in advance for your knowledge.
A fellow ocean geek,
Greg Graeber

:welcome: to TONMO! Sadly, I have no clue on your question, though...

Hello Cephalopod lovers,

I teach marine science a the Dauphin Island Sea Lab in Alabama, USA. Presently, through my door I hear 2 of my collogues dissecting squid. My question is ... In all female squid, are the large thick white organs the nidamental glands, anterior to the egg mass, and egg mass the correct term for the gelatineous structure holding the eggs? If so, what is the reddish/pink organ/structure connected and associated, generally on the anterior end of the nidamental gland? Which of these organs is actually the ovary and are cephalopods the only animals which possess a nidamental gland? Thanks in advance for your knowledge.
A fellow ocean geek,
Greg Graeber


OK Here goes, The large gelatinous mass (or kinda feathery in an immature specimen) at the apex of the mantle is the ovary. Attached to that on either side is a sort of wavy meandering structure this is the oviduct, then there is a roundish gland attached to the end of the oviduct, this is the oviducal gland. The long white glands on top of all the viscera are the nidamental glands and in Loliginids (like the california market squid) there are smaller accessory nidamental glands attached to this. The reddish/pinkish structure is the digestive gland a hepato-renal gland essentially the sewerage works! I've attached a diagram and picture of Nototodarus sloanii an ommastrephid squid from NZ (that I work with) note: it has no accessory nidamental glands!

There is a downloadable online dissection guide at www.utmb.edu/nrcc/model.html
Cheers

Jean

:cuttlehi: Greg!

Below is an image of a female Pholidoteuthis - sorry the head looks a little funky, it seems to have been twisted in the photo so that you can see the dorsal head surface but the ventral mantle cut (which is why the funnel retractors are twisted). In this species the accessory nidamentals are quite large, so you actually get four large white glands in there. Not sure what the situation is with your squid - is it Loligo? I'm not really much of an internal morphologist, so someone will probably come along and point out a grievous error on the diagram below...

Here's another more detailed illustration (http://library.thinkquest.org/26153/marine/sketch/686.jpg) (but without the glands), and the Cephalopoda Glossary (http://tolweb.org/accessory/Cephalopoda_Glossary?acc_id=587) on the Tree of Life may also be helpful.

Not sure if anything else has nidamentals.

Apparently Nidamental Glands are also found in Gastropod Molluscs and some Elasmobranchs! I learned something today and it's only 9.15 am :wink:

J

Now I'm confused. I've been doing this for a while, but none of the specimens on those links look much like ours so I am trying to attach some shots. Any other help would be great! We get them frozen in 5 pound blocks from California, so I guess they are Liligo. Here they are (hopefully?) any ID of parts and Genus or Species of these would be awesome. Again thanks for the help!
Greg

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I would say...

Thank you all, I really appreciate it.

.....ummmmmmmmmmmmmmmmmmmmmm

Kat, where did you get that Pholidoteuthis pic from? Accessory nidamental glands? Perhaps I am getting old and forgetful, but if those truly are accessory glands then I'm inclined to believe this brute deposits eggs of some sort to the sea bed.

I don't recall ever having seen them before on Pholidoteuthis, would be very surprised if it had them, and wonder whether they are some other structure (oviduccal gland?; distended distal portion of oviduct?).

I have a similar question. I'm trying to sort out the reproductive structures in Gonatids and..although it may seem silly......I'm having trouble determining what structure I'm looking at. It is purplish and solid (I preserved the specimen a few days ago) at the base of the mantle, but there is no evidence of eggs. I'm pretty sure this is a juvenile based on size (may be a small adult - there are no tentacles to look for hooks) so would ovaries even be developed? I'm guessing its female since I couldn't see any male structures but could be wrong.

Anyone have any ideas?

Purplish and solid? Hmmmm. The only other structures inside the viscera that are non reproductive that are likely to be this colour are: the digestive gland, OR the stomach caecum (or stomach), OR the spiral caecum.

It is more likely to be the digestive gland if it is solid.

I managed to locate both the stomach and the digestive gland (its pretty hard to miss - they're huge in Gonatids) and the caecum I believe was behind this structure (a large blind sac coming off of the digestive tract just after the stomach)....that's why I was thinking reproductive organs

Can you post a photo?

I'll try to get a picture and post it.

Sorry that it has taken so long to post these pictures.

The first picture is of the 'purple' structure and the second is of the structures behind it. My supervisor and I pulled it apart looking for other organs, but this is my best reconstruction.

Cheers.

Is that a preserved specimen? It looks like it! To me your purplish solid structure looks like a full caecum. Many squids do the bulk of food storage/digestion in the caecum not in the stomach. If it was N. sloanii I'd say it was the caecum containing a (large) meal of cephs and perhaps some crustacean such as Euphausiids (the eyes can make the contents quite dark). The tubules behind it look like pancreatic ducts. The small sac at the end of the gill is one of the branchial hearts.

J

looks like a wonton.

Is that a preserved specimen? It looks like it! To me your purplish solid structure looks like a full caecum. Many squids do the bulk of food storage/digestion in the caecum not in the stomach. If it was N. sloanii I'd say it was the caecum containing a (large) meal of cephs and perhaps some crustacean such as Euphausiids (the eyes can make the contents quite dark). The tubules behind it look like pancreatic ducts. The small sac at the end of the gill is one of the branchial hearts.

J

Thanks Jean,

When we pulled it apart a bit, it was solid cells...there wasn't any space to suggest it being a caecum. This is the only specimen we've found so far that had this structure...which explains why I'm a bit stumped.

Ok If it's solid I'm stumped too..........I wonder if squid get cancer......a Tumour perhaps????? Can you get a close up shot of the "cell" structure? Maybe down a microscope?


J

Jean, if it was preserved it would become a solid structure; seen this so many times. Often the fluids inside take on a gel-like consistency and flake when teased apart.

Thanks Steve, never thought of that (D'oh :roll:), none of mine were preserved...........so I stand by my earlier comment that it looks like a full caecum!

but Do cephs get cancer??????????

J

There are many kinds of tumors; not all tumors are cancerous. Lots of mammals get varieties of tumors. Do cold blooded animals? Do fish? Invertebrates? In any case, this specimen didn't die of cancer or benignant tumors.

Very curious.

Maybe it had fatal sushi at a not to be named sushi bar on E9th and Stuyvesant? :wink:

There are many kinds of tumors; not all tumors are cancerous. Lots of mammals get varieties of tumors. Do cold blooded animals? Do fish? Invertebrates? In any case, this specimen didn't die of cancer or benignant tumors.

Very curious.


True........tis brain fade.......put it down to the start of student enrollment and the accompanying chaos!

Teleost Fish do get tumours, both benign and malignant, melanomas are especially common I believe. Cartilaginous (Chondrichthys) fish (sharks etc) are not known to get them.

In any case, this specimen didn't die of cancer or benignant tumors.

Very curious.

I'm pretty sure cancer wasn't the cause of death...

hello again,

So I have been diligently dissecting squid for my project and the more I dissect, the more I realize that the purple structure I was confused about must be the caeca (Jean and Steve were right). That'll teach me to second guess the experts :notworth:

Thanks again for the help.:grin: