Sand and young rays.

[andersp90]

Since the Amazon basin is huge, I would imagine it is pretty varied. Much of the sediment load of the river must come from the erosion of the Andes Mountains.

So, while I can't comment on the specifics of the Amazon River basin, here is some info that might be helpful.

The substrate type is going to depend on where on the river you are. In the areas where the river is flowing faster- there is going to be larger sediment, in general less eroded (more angular, not as rounded). Where the river slows down, the river does not have enough energy to carry the larger sediment, so it gets buried. Probably more mud in these areas. By the time particles get this small they have been weathered a long time, so in general it should be pretty rounded in all but the hardest mineral types.

Now throw into the mix seasonal changes in water flow and thus the energy of the river and it's ability to carry sediment, add in the huge areas of the amazon river that these animals inhabit and I don't think it is possible to make generalizations about something as big as 'The Amazon River Basin'.

Also, keep in mind that in any river, there are areas where the water is flowing faster and where it flows slower. These different areas will have different types of sediments in them. In a river, if a fish prefers a more rapidly flowing area, or an area with a different type of substrate it moves. In our captive environments, this is not possible.

It all get's quite complicated the more you think about it. That's why it's so cool though!

You may be able to find articles on the sediment types within the amazon river basin.

Would some river sand-sampels from Peru, brazil and Colombia be usefull?

 

[amazongirl]

Would some river sand-sampels from Peru, brazil and Colombia be usefull?

It would allow you to know what the the sand is like in that portion of the river at the moment in time but I don't think it would tell you much about the river in general, or even a specific country. That would be kind of like trying to characterize all the river sediment in England based on one sample.

 

[Bogwoodbruce]

When you were saying about african ccihlids being in sand and not damaging gills etc,,, cichlids only take sand though their mouths and gills which is everynow and then.

Rays are on the sand or substrate pretty much all the time. How can you compair that??? also i image that rays gill rakers are much more delicate than those of cichlids.

Just my 2cents.

 

[andersp90]

When you were saying about african ccihlids being in sand and not damaging gills etc,,, cichlids only take sand though their mouths and gills which is everynow and then.

Rays are on the sand or substrate pretty much all the time. How can you compair that??? also i image that rays gill rakers are much more delicate than those of cichlids.

Just my 2cents.

Thats good to know.

Try and read about some of the Malawi species. Or mabye even the geophagus species.

Then comment again.

 

[Bogwoodbruce]

Thats good to know.

Try and read about some of the Malawi species. Or mabye even the geophagus species.

Then comment again.

Yeah, at the shop we have over 70 tanks of wild african cichlids, my boss has been out in the lake, most the other mbuna species dont even sift through the sand and will eat the sediment and algae from the rocks.

It mainly the open water haps, and larger predators that sift.

Anyway how can you compair geophagines to rays, geos have developed over time and have mouths feeding habbits adapted for substrate sifting, thats why i always keep my geos on fine gravel. I dont like sand..

And it wears your impellor down.

Im gonna stay out of this discussion

I dont know everything just what i know from personal experience.

 

[Nic]

this is why i keep barebottom....