and if you want more "scientific proof" heres some copy/paste action from the most knowledgable zoologist/chemist/herptologist i have ever seen on a frog forum


Originally Posted by brinkerh420
I found that it was frustrating not being able to mix species. I have a tank with a fire bellied toad and a tank with a green tree frog. The green tree frog stays at the top, the Toad stayed in the water, so it seemed like they could coexist, but I took the advice of just about every member of dendroboard, and didn't mix them. The only problem with mixing them would be 1) toxins from fire bellied toad, and 2) Fire bellied toad got all the food. anyone have anything else to add?

Will
Actually those are not the only reasons to not mix species from seperate geographic regions. Mixing animals from different regions allows parasites and pathogens to jump hosts and adapt. This can result in epidemics that can cause a lot of problems such as the mycoplasma epidemic that is killing off native tortoises in the Gopherous genus (and box turtles now), ranaviruses, and there is not evidence that the strains of chyrid killing amphibians globally may be the result of more than one strain with little or low impact on the amphibians, being able to mix resulting in increased lethality.

Do not mix species from seperate regions.

The problem when you are mixing species from different geographic regions is that you are really setting the stage for a possible outbreak of pathogens/parasites. We have seen this in other animas for example the massive mortality caused by mycoplasma infections in native tortoises of the Genus Gopherus, and now box turtles. We also have seen massive mortalities from chytrid which appears to be the result of different geographical strains getting mixed together resulting in a massive pandemic. This is why the whole argument of "healthy", "stress free" or other claims are moot as this is a direct risk to the enviroment and native species already under pressure. The water that you dump down the drain or plant cuttings or substrate that is discarded is all a risk. This is one of the major reasons why animals from seperate regions should never be housed together. It is one of the simplest things we can do to protect the hobby and the enviroment. There is a petition that is under review in front of USF&W right now to ban the import and interstate transport of amphibians because of the risk of chytrid, you should do your best to help the hobby by not giving them more points as to why the hobby should be banned from interstate transport without certification that the animals, eggs or other materials are chytrid free.

Ed


"Ed is Ed Kowalski the lead keeper at the Philly zoo. He is also one of the best biologists/herpetologists I know. His experience in breadth and time beats most of ours here, myself included."



Actually folks I chose the Beginners forum for the point that this is where people tend to inquire about mixed species exhibits so this is the appropriate venue for the topic. I am breaking this into parts as otherwise the single post would be huge running the risk of losing some of the important points.

Hi Chuck,
There are few basic items that are best illustrated with a simple set-up as opposed to a complex set-up. I intend to get to the potential arboreal part soon (and will include ideas such as visual barriers, refugia etc). (I intend to address some of the hybridization issues but anura is a large genera with some possibilities that preclude hybridization problems).
The whole point to this discussion is to hopefully provide some guidelines for the people who may be considering this venture.

On to the second part of spatial needs. The following paragraph is based on the absolute minum supplied by a simple set up. The most important point is that amount of space provided by the 5 gallon/frog rule begins to break down pretty quickly.

In enclosures larger than the 5.5 gallon tank used in the example, the space not used by a frog like a tinct can be much more dramatically different as in many tanks, the height increases faster than the length and width of the tank(although there are often tanks such as 20 longs that are not as problematic.
For example a ten gallon tank is 20 long x 10 wide x 12 high giving a total of 2400 cubic inches. However if we then calculate the usable volume of the tank using the same criteria used in the 5.5 gallon tank (in the first post) we get 3 inches high x 10 inches wide x 20 inches long we get 600 cubic inches or 25% of the total volume of the tank (and only a 50% increase of the usable space of a 5.5 gallon tank).
If we then go up to a 20 gallon high tank 16.5 high x 12 wide x 24 long we get 4752 total cubic inches with a usable area of 3 x 12 x 24 = 864 cubic inches. In a 20 gallon high tank the amount of usable space drops to a low of 18% of the tank (or a total of 3.6 gallons) yet the 5 gallon/frog rule has us then placing four dart frogs in the tank. In a 20 gallon long (approximate external dimensions of 30x13x12 gets 4680 cubic inches with a usable space of 1080 cubic inches a use rate of 23% or a total of 4.6 gallons).
When looking at even larger standard enclosures such as 55 gallon aquaria (48 x 12 x 20 = 11520 total cubic inches) with a usable space of 1728 cubic inches or a total of 15% of the tank space or a total of 8.25 gallons. (Or based on the 1frog/5 gallon rule 11 frogs which would each have 157 cubic inches each or a total volume of .68 gallons each)
So the usable space indicates that there is something wrong with this method of determing density of frogs as the actual density of multifrog enclosures exceeds the 5/gallons frog limit commonly recommended by the masses as the size of the tank increases (each frog has 300 cubic inches of space/frog (using the 5 gallon/frog rule) in a ten gallon, and 270 cubic inches in a 20 long as opposed to 157 cubic inches of space in a 55 gallon). (Using ten gallons per frog is slightly better but still suffers the same drawbacks).
This then raises the question, then why are we able to keep these frogs at these densities in larger enclosures?

Part of the reason why is because the large enclosures lack floor space, they provide vertical room for decorations that allow the frogs to use more of the volume of the enclosure (but still not an equivalent volume per frog). These decorations provide visual barriers allowing the frogs to escape one another much as they would on the forest floor.

Additionally, in the larger enclosures the minimal amount of floor space decreases but the total amount of space increases. It is this other space that needs to be considered for other species.

Any further questions/comments? If not, I hope to address some of the complex enclosures items.

Ed


I apologise to the original poster for changing the subject, but Ed, in your opinion should this be standard procedure for any water change regardless of species?
I do... Yes it is acutally one of the simplest actions people in the hobby could do to demonstrate that they are concerned about preventing parasites/pathogens from jumping to native populations. People often forget that in many cities, the run off from storms enters the same treatment lines as regular sewage and in heavy storms it can result in untreated discharges into the enviroment. There is data out there now that demonstrates that some pathogens like chytrid can live for potentially more than a month in water that contains nutrients.

Ed


if you want some more reasons NOT to house different species in the same enclosure just let me know id be more than happy to use google for you