Are These Brackish Species

[iliveinazoo]

I was in the LFS with the girlfriend and at the weekend was suprised to see the new additions to their Brackish Water tanks:

1. A few Elephant Noses - I've heard that these are freshwater and are difficult to keep healthy; maybe they are difficult to keep because they only do well in a lightly brackish system?

2. Pygmy Puffers - the girlfriend wanted to buy these on the spot but I refused because Pygmy sounds a bit like Dwarf and I understand that Dwarf Puffers are freshwater. Is there a Pygmy Puffer and are they brackish?

3. Soft Shelled Turtle - I didn't think that there were any Brackish water Chelonia? Is there such a thing?

Your views/experience would be much appreciated

 

[jennybugs]

Pygmy puffers are dwarf puffers and strictly freshwater fish

 

[Colin_T]

elephant nose (Mormyrids) are freshwater and don't tolerate salt. No idea about the others but there is a posibility the shop simply put them in that section because they didn't have spare tanks for them in the freshwater section. The tanks themselves might not have had salt in them.

 

[nmonks]

1. A few Elephant Noses - I've heard that these are freshwater and are difficult to keep healthy; maybe they are difficult to keep because they only do well in a lightly brackish system?

Generally mormyrids don't occur in brackish water. There are odd exceptions, e.g., Brienomyrus brachyistius, but none of the commercially traded species.

2. Pygmy Puffers - the girlfriend wanted to buy these on the spot but I refused because Pygmy sounds a bit like Dwarf and I understand that Dwarf Puffers are freshwater. Is there a Pygmy Puffer and are they brackish?

Not brackish water. May well tolerate low salinities, sub-SG 1.005, but since these puffers are almost always best kept alone, I can't think of any reason to keep them in brackish water.

3. Soft Shelled Turtle - I didn't think that there were any Brackish water Chelonia? Is there such a thing?

Many species of turtle occur in brackish water. The classic example is the North American diamondback terrapin, Malaclemys terrapin. It is quite easy to keep in aquaria, and in the US particularly, reasonably widely traded.

Cheers, Neale

 

[iliveinazoo]

definately not that species of elephant nose i think that it was Gnathonemus petersii.

I'm now glad that i didn't buy any pygmy puffers (or the others) on impulse - i don't like the word tolerate it makes me think that the fish will be uncomfortable their whole life.

The puffers were being kept with small cherry shrimps but they weren't attacking them which i found strange! my figure 8's would polish them off in seconds.

 

[nmonks]

In biology, the word "tolerate" means something quite specific. It doesn't necessarily mean an animal is unhappy or uncomfortable; for a start, ideas of "happiness" and "comfort" probably don't make much sense when talking about animals. Rather, what is meant here is that an animal will live under these non-optimal conditions, but may exhibit a higher degree of sensitivity to disease, or may not be able to breed.

Neon tetras for example "tolerate" hard water, and millions of aquarists keep them thus. But they cannot breed under such conditions, and it's probably fair to say their longevity isn't as high as in a soft water aquarium. (It's still a lot better than in the wild though, where they barely live a year, millions dying off during each dry season.)

In the case of freshwater puffers, because they evolved from marine ancestors very recently, they generally tolerate salt rather well. Some species, such as green spotted puffers, can actually be kept in marine tanks (seemingly rather well) even though wild fish are apparently strictly freshwater fish. Think of it this way: although living in freshwater, these puffers still have at least some of their "marine habitat" gear in their bodies, and are able to switch these bits on should the need arise.

Cheers, Neale

I'm now glad that i didn't buy any pygmy puffers (or the others) on impulse - i don't like the word tolerate it makes me think that the fish will be uncomfortable their whole life.

 

[LauraFrog]

An interesting turnaround, freshwater fish in brackish tanks... I'm used to seeing brackish fish dying in freshwater tanks, overstocking of my own tanks being the general result. (Die hard fish rescuer here.)

I wonder how long it would take to breed a line of a 'freshwater' puffer species - keeping and breeding them in strong brackish or marine - until you had a fish that actually preferred those conditions? I've seen the preferred degree of salinity vary greatly with mollies within one or two generations, it would be an interesting experiment for anybody with the tank space and time to attempt it.