• We have updated the guidelines regarding posting political content: please see the stickied thread on Website Issues.

Shells: Rivers Versus Seas

Frideswide

Frideswide

Fortea Morgana :) PeteByrdie certificated Princess
Joined
Jul 14, 2014
Messages
16,310
Location
An Eochair
Playing Skyrim with a mod that introduces shells and fossils for one to find and pack-rat over. The distribution matches my own perception (and is therefore totally correct, FACT!) that shells are found in oceans rather than by rivers. Some in rivers, for example water snails, but still...

But is this true? IRL I mean. And if so, why? Assuming that it wasn't a wizard that did it, what is the difference in the two environments which means that shells are better as a solution in one rather than the other?

Shells and humans have a very long relationship. I'm wondering if anyone knows of an overview of that relationship?
 
Frideswide said:
Playing Skyrim with a mod that introduces shells and fossils for one to find and pack-rat over. The distribution matches my own perception (and is therefore totally correct, FACT!) that shells are found in oceans rather than by rivers. Some in rivers, for example water snails, but still...

But is this true? IRL I mean. And if so, why? Assuming that it wasn't a wizard that did it, what is the difference in the two environments which means that shells are better as a solution in one rather than the other?

Shells and humans have a very long relationship. I'm wondering if anyone knows of an overview of that relationship?
Click to expand...
I don't know for a fact but I would guess that it has something to do with methods of eating and opportunities for it? Many of the shells I can think of eat either by burying themselves in mud or sand and siphoning or by scraping algae and stuff off rocks. The sea has a much greater variety of environments involving mud, sand and rocks and therefore a much greater capacity for varieties of shell.
 
Shells are mainly... calcium? are seas richer in calcium than rivers?

What is a tortoise shell made of? and a turtle?
 
Min Bannister said:
I don't know for a fact but I would guess that it has something to do with methods of eating and opportunities for it? Many of the shells I can think of eat either by burying themselves in mud or sand and siphoning or by scraping algae and stuff off rocks. The sea has a much greater variety of environments involving mud, sand and rocks and therefore a much greater capacity for varieties of shell.
Click to expand...
Probably because it was an inexhaustible and easy source of food supply, oysters are also river food, as are freshwater Clams, mussels, etc. All they would have to do back in the day would be find 'em, lift 'em, cook 'em or eat 'em raw I guess.
 
Does the tide help with filter feeding? Do shells help preserve the mollusc's environment when the tide goes out?
 
Tunn11 said:
Does the tide help with filter feeding? Do shells help preserve the mollusc's environment when the tide goes out?
Click to expand...
Well, I know from my sea-fishing day's that 'razor shells' feed when the tide is in and covering them, as they open up and take food via syphoning, thereby filtering the plankton from the sea water. And when the tides out, they bury themselves in the sand. Mussels/Cockles, etc also feed when the tide is up, as does most sea shell life.
Much the same principle with river varieties of shell life filtering out their food from the passing water.
 
Last edited:
The below is a UK freshwater 'swan mussel' shell - I picked it up by a small pond a few years ago and donated it to the fish in the barrel. It's not unusual to find beds of them in streams, but if otters find them they root them out and eat them, leaving the broken shells about the place.

IMG_20220716_0838109.jpg
IMG_20220716_0838179.jpg
 
I was going to take a picture of the freshwater mussels that line the Royal Military Canal where it passes through Hythe but the water was turbid and I couldn't see them this morning.
 
Erinaceus said:
I was going to take a picture of the freshwater mussels that line the Royal Military Canal where it passes through Hythe but the water was turbid and I couldn't see them this morning.
Click to expand...

If you get another chance...... :twothumbs:
 
Frideswide said:
If you get another chance...... :twothumbs:
Click to expand...
This morning I stumbled upon some photos I took showing mussels along the Royal Military Canal when the water level was exceptionally low four years ago (if Napoleon had been able to wait until 2019 it wouldn't have presented much of a barrier to La Grande Armée).
The gulls took advantage of a new food source!
 

Attachments

  • mussels1.jpg
    mussels1.jpg
    240.5 KB · Views: 15
  • mussels2.jpg
    mussels2.jpg
    270.3 KB · Views: 15
  • mussels3.jpg
    mussels3.jpg
    201.4 KB · Views: 12
Erinaceus said:
This morning I stumbled upon some photos I took showing mussels along the Royal Military Canal when the water level was exceptionally low four years ago (if Napoleon had been able to wait until 2019 it wouldn't have presented much of a barrier to La Grande Armée).
The gulls took advantage of a new food source!
Click to expand...
Gullible mussels I guess!
 
I've been told that shells are like trees in that if you count the rings you have a pretty good approximation of the age of the creature that once lived there. I have a mussel shell from East Falkland which has over 40 rings so the unfortunate inhabitant would have been over 40 years old.
 
I wondered for a long time why a marvellous pub l visited in the Forest of Dean area was called the Ostrich.

Years later, l read that it has nothing to do with African wildlife, but that it’s a contraction of “Oyster reach”, i.e. a section of a river where oysters are commonly found.

It turns out that it’s not uncommon as a pub name in the UK.

maximus otter
 
You must log in or register to reply here.
Back
Top