Biodiversity within a given habitat

[Kinbote]

Not strictly a cichlid question, but I figure this is probably where the experts hang out.

As far as biotope creation goes, what's the general opinion on the number of species that would likely be present within a given area?

My guess is that compared to the average fish tank, where you'd find any life at all you'd probably find more individuals but fewer species, but I'm not really basing that on anything concrete. I'm just assuming that where two species occupy a similar niche, one probably does it better and would outcompete the other, so I probably wouldn't expect to see more than one type of tetra, one type of cory, one type of eartheater and so on in close proximity. But then a lot of similar species have a pretty wide range, so there's got to be some overlapping.

What do you guys think? It's hard to find underwater footage from the amazon.

 

[skjl47]

Hello; Here is an example, from memory so it bears further checking out, using the birds in a backyard. You may have a number of types of sparrows, finches, woodpeckers and others visiting your back yard each year.
Consider the nuthatch. The explaination given was that they have an adaptation of their feet that allows them to go up and down the side of a tree. Having two toes facing front and two toes facing back, where most birdss have three in front and only one in back. This allows them to exploit a food source easier than other birds so they are not in such direct competition in the same habitat. Some behavior adaptations do the same sort of thing. (one does not come to mind just now) and there are combinations of behavior and physical adaptation. This allows similar animals to share the habitat in what i have known as separate niches. The concept of a niche applies to all the other essential parts of life as well as hunting food. Shelter, nesting, water and such.

The Amazon basin will have the things needed for life in abundance. Lots of basic solar energy all year and plenty of water. I seem to recall it being one of the most biologically diverse habitats of the world, others are some of the coral reefs. It has been referred to as the lungs of the world.

I suspect that there can be a good number of tetra species in one area in the Amazon and that they coexist by having some sort of adaptation that allows them to exploit a slightly different portion (niche) of the common environment and that way avoid a lot of direct competition.

 

[Aquanero]

This is an old paper but might cover the question your asking.

http://cires.colorado.edu/limnology/pubs/pdfs/Pub111.pdf

 

[Kinbote]

This is an old paper but might cover the question your asking.

http://cires.colorado.edu/limnology/pubs/pdfs/Pub111.pdf

Thanks, that's exactly the kind of thing I wanted. Too bad they don't give a species breakdown per lake, though.

 

[Kinbote]

Yeah, I remember Darwin counting a huge number of plant species exploiting slightly different niches within a square yard of a field near his house. The trouble is in estimating how many niches and how much specialisation there is in the amazon (or wherever) without hard data.

 

[Kinbote]

Here's an article cataloging the species collected from a 300m stretch of a single river over a few months: http://www.scielo.br/scielo.php?pid=S0073-47212001000100016&script=sci_arttext

 

[Kinbote]

The above article is from a semiarid region, so not quite as species-rich and not quite the same species as the habitats biotopers are likely simulating.

Here's one from the upper Amazon floodplain; the sampling area is a bit more spread out, but it's still fairly localised: https://docs.google.com/viewer?a=v&...4003/Albert%20PDF's/Correa-et-al-2008_JFB.pdf