Green Wolf Eel Brackish Compatible?

[Dave Legacy]

Hi,

Here's the run down. I've recently been working on putting together a 37G Tall (29.5 x 12.5 x 25.5) Oyster Reef themed tank to house a single Green Spotted Puffer. GSPs start off in mid-ranged brackish water and then migrate out into full marine as they reach maturity at about 4" in length.

I've recently become facinated by the Green Wolf Eel (C. subducens) and have been thinking about keeping one. After doing some research I have found that Green Wolf Eels don't require a lot of space because they don't move around and that there has been successful breeding of an adult pair in a 30G tank. This meaning my tank size should suffice in housing 1 adult. I have also found that tankmates are ok as long as they wont fit in the Green Wolf Eels mouth (GSP reaches adult size of 6" and GWE adult size of 18") and that puffers are considered one of the acceptable tankmates.

Here's are my questions:

1. Does anyone have any experience with housing a Green Wolf Eel any species of puffer together? What about behavior towards any type of tankmate?

2. Does anyone know what the growth rate of a Green Wolf Eel is? In what time frame should I expect to see it reach the adult size of 18".

3. I have read on Fishbase.org that the Green Wolf Eel has been seen in brackish water. Does anyone have experience with this? If they are tolerant of brackish water, or spend their juvenille life in brackish that would mean I could combine the 2 fish together right off the bat.

Any insight on this topic would be highly appreciated. If I can pull this off I'll start stacking my oyster reef in ways to form caves for the Green Wolf Eel.

Thanks in Advance,
David

 

[aquamanA]

jeez all this wolf eel stuff is way too advanced for me to even know about all this stuff I heard that the wolf eel is a very scary creature plus it takes a long while to look after it so yeah you do your best and I hope it all goes well.

 

[nmonks]

Hi Dave,

I've seen these fish but never kept them, so cannot speak with authority.

What I would suggest is that since keeping even regular marine fish at SG 1.018 is usually fine (and was normal in the early days of marine fishkeeping), then a brackish-tolerant species should easily handle SG 1.015, perhaps even a bit less.

When adapting marine fish to brackish water, I like to set up the tank to marine conditions, and then reduce the salinity with each water change.

I think these fish should look great together. The wolf eel wants as built-up a habitat as you can create... it sounds like these fish come from the rubbly area in shallow water where all the shells and broken coral pieces form a rocky reef. This is also ideal puffer habitat, and very like the places I've watched Sphaeroides spp. puffers hunt in Florida. Incidentally, also common in these rocky reefs are magrove saplings, and it might be fun to stick a couple of these plants in the tank, too.

Personality-wise, I think you will be okay provided the fish don't compete for space. I'd create an open sandy area at the front where the puffer can beg for food without being too close to the wolf eel. Conversely, I'd make sure the reef structure had enough width/depth that the eel could completey retreat from the puffer should it want to. That way, each should be happy.

I'd be tempted to add the wolf eel first, and the puffer afterwards. I've found puffers that are perfectly tolerant of existing fish often aggressive towards newcomers.

For more info on the wolf eel, you might try asking on the marine forums. As far as I know, these fish are never traded as brackish water fish. This doesn't mean they aren't good brackish water fish... there are several marine fish (like the dog-faced puffer) that make superb brackish water fish. But you will find a total absence of information on them in the usual fresh/brackish water books and web sites.

Cheers,

Neale

 

[Dave Legacy]

Neale,

I tried the Marine section and this is all I got:

GSP's (t nigrovidis) start out in fresh to water and migrate to light brackish water.

However Green Piuffers (T. Fluvalitis) start in light brackish and go into full salt, if you have T. Nigrovidis, the far more common species (IME) then full marine would kill it.
be sure that you have the right one. http/puffernet.tripod.com/confusion.html

Okay moving on, what is an oyster themed tank? if you have any noncoral invertibrates a Green puffer will eat them, it will also nip the fins and scales on your green wolf eel.

I do not believe that GWE's are anadroumous, heading into water of lower salinity to breed, I do think that should you get say an 8" individual you shouldbe able to keep it in heavy brackish 1.017 for a number of months without serious harm coming to it.

- Opcn

 

[nmonks]

Hi David,

I used to think spotted puffers (T. nigroviridis and T. fluvialitis) both needed brackish, not marine water, but others with more experience have changed my mind about this. Many reliable reports say they will do well in marine aquaria (as adults at least). In the Aqualog pufferfish book, for example, Ebert comments that specimens kept in freshwater are smaller and more delicate than when kept in either brackish or salt water. By brackish he seems to mean SG 1.010, which is also what is recommended in the Aqualog brackish book.

I have never kept these species so cannot comment on this from personal experience. I have kept a marine puffer in brackish without any problems, so my assumption is that the estuarine puffers (and other fish) are perhaps more adaptable than we give them credit for.

This is, for example, one reason I think trying out the green wolf eel in brackish is worth a shot. If you look at the list of marine fish that swim routinely into brackish water, it's quite an eye-opener. Just among the commonly traded tropical marine aquarium fish you can add batfish, emperor snappers, dog-faced puffers, sharpnosed puffers, sergeant majors, and stripeys. In the wild, the list includes stuff like tarpon, tuna, mullet, halfbeaks, barracuda, jacks, snook, herring, stingrays, etc., etc. There are countless small fish like flounders, gobies, puffers, and atherines that we don't see traded but are common inhabitants of estuarine waters.

The idea that there is a "wall of salinity change" at the edge of the sea that stops marine fish going into brackish water is completely wrong. A significant proportion of marine fish use estuaries either as feeding grounds or spawning grounds. That most of them don't go into weakly brackish or freshwater tends to colour the argument, so some people (aquarists) don't think of them as "brackish water fish", but anyone with a knowledge of marine biology or even sea angling will know estuaries are key parts of the marine ecosystem.

Cheers,

Neale