Pathological ammonites

[Phil]

Very interesting discussion. I have two and a half questions for you:

1) Is it possible to differentiate between parasitic and fungal infection in ammonoids?

2) Has parasitic distortion of the shell been observed in Nautilus?
If so, is the modern Nautilus an appropriate baseline for comparison? Or do the differences in conch morphology not allow for a direct correlation?

Phil

 

[spartacus]

I'll sit this one out if you don't mind I may learn something if I shut-up.

 

[Architeuthoceras]

Phil said Fungal 8)

That is the first time I have ever seen the words fungal and ammonoid used in the same sentence. Of coarse the fist time I really saw parasite and ammonoid in the same sentence, was just after this thread started. I was just starting to get a grip on the difference between injury and parasitic/"fungal"/viral/biologic.
This is all a long way of saying I dont know!

Nautilus kept in captivity produce a discolored and distorted shell...Fungal/parasitic

Injury and repair is usually obvious, a jagged edge with new shell and ornamentation picking up where it left off, only offset. A parasite would probably cause a longitudinal scar that would last until it was extirpated. What would a fungal infection look like?

More study is needed, unfortunately I really must get back to work now

 

[spartacus]

Kevin, it is time for me to speak as I've just learnt something

extirpated

pukka new word logged & ready for use

 

[Phil]

Phil said Fungal 8)

OK, I could swear I saw a reference to this a couple of days ago, hence I posted the question. :? Typically, I am damned if I can find the reference now, despite extensive searching. Best forget I mentioned it unless I can turn up something substantial!

(I've confused myself now....)

 

[Carl J. Bobrow]

Nautilus deformation "black shell syndrome"

Good day all, a bit of information and more to come on the topic when I have my notes and images in front of me. The Nautilus seems to develop quite quickly in captivity this may be due a variety of factors. One of the many symptoms of captivity is the deformation of the shell "black shell syndrome.” I will post some images when I get the chance. These may be stress related due to water chemistry, lack of vertical migration (pressure change), food, light etc... The natural environment of the Nautilus is at mid depth on the reef shelf 200ft and below. Therefore, changes in shell development are to be expected but some of them are rather startling. The pathology report done at the National Zoo to one of the Nautilus which died a few years back as well as pathology on living specimens do not indicate infection or hosts as the result although there are host living opportunistically in the locality of the deformation. So the best guess is... environmental factors are at play causing abnormal shell development.

More to come

Regards

Carl




PS:if you want to find a wonderful text, Treatise on Invertebrate Paleontology, which includes three volumes on Cephalopods (only two available) try these sites locations

http://www.ku.edu/~paleo/treatise.html

http://rock.geosociety.org/bookstore/default.asp?oID=0&catID=13&rslID=2

http://rock.geosociety.org/bookstore/default.asp?oID=0&catID=13&pID=TREK

 

[Architeuthoceras]

Thanks Carl,

Do you know of any parasitic shell deformation in wild Nautilus shells? I seem to recall that Peter Ward broke some Nautilus shells just to see how they repaired themselves and what affect it had on their bouyancy, but I cant remember anything about parasites.

And thanks for the heads up on the treatise.

 

[Carl J. Bobrow]

Nautilus shell reply

Thank you for the question and the reminder, I posted the mail from work and forgot to add the obvious. The American Museum of Natural History has a wonderful collection of Nautilus shells. Dr. Landman has permited me on occasion to examine these (no big deal really) and what we found was that in fact in the wild Nautilus do exhibit the shell deformation that is common or ever present in captivity. Though I am not sure about those kept at Palau (need to check on this). So it seems that this is a natural state for some reason for some Nautilus the big question is why. One of the things on my list of things to do is to check the collection at the Smithsonian, when I get the chance to breath, and see what they have.

As a side bar I think that the Spirula Spirula has been overlooked and I am trying to avocate a more intensive study of them, perhaps a good Phd. project for someone, I wish I had the time to do it! hahahahaha

more later and pix to I promise

CjB

"freedom from tyrrany"

 

[Architeuthoceras]

Looking closer at some of my fossils, I found this Eosyngastrioceras hesperium (Late Mississippian, Arnsbergian Stage) with a small pathology

Top Picture:
Lateral and ventral view, the pathology is on the right side of the ventral view


Lower Picture:
a closeup of the pathology

 

[Carl J. Bobrow]

Bite marks!




This is exciting, well sort of I suppose.

A quick note and I trust others will confirm my opinion, the "nick" or "grove" exhibited in the pic (previous post, good shot too) is that of a predatory bite. You can view such "blemishes" on modern day Nautilus shells, they are often attributed to Octopus bites (P.D. Ward etc...).

I know I promised some images on deformed Nautilus shell and I will. Although I loath excuses here is the current one, these pics live on my sons computer at home and I have had little time to log on in the evening due to travel and work at the Smithsonian. I will get these out as well as some additional images of the bite marks on Nautilus shells for comparison.

Regards

CjB