Logo
Please visit our Sponsors
FAQs on Mormyrid Fishes Compatibility

Related Articles: Mormyrids, ElephantfishesElectrogenic Fishes,

Related FAQs:  Mormyrids, ElephantfishesMormyrid Identification, Mormyrid Behavior, Mormyrid Selection, Mormyrid Systems, Mormyrid Feeding, Mormyrid Disease, Mormyrid Reproduction, Bony Tongue Fishes, Electrogenic Fishes, Aba Aba Knifefish, African Butterflyfish, Arapaimas, Arowanas, Featherfin Knives, New World Knifefishes,

Tough Decision to Make; Mormyrid comp.      6/14/17
Hello Crew! This is Renee from Idaho with yet another situation specific mormyrid question for you.
<Fire away.>
But first I have to tell you that my BGK is doing beautifully, staying healthy, growing, and continuing to enchant every day (getting the catfish for her was a brilliant idea! Not only are they keeping the tank clean, but she feels more comfortable with them than any other dither fish I've tried and now she moves around the entire tank - thank you again for that suggestion).
<Cool.>
However, in the past I've shared with you my desire to get an elephant nose someday. I've put it off because that species is not available in my area and because I wanted to focus on my BGK and other tanks, but now I find
myself in a situation. My local aquarium store, who I previously asked about the availability of the elephant nose fish, gave my information (with my permission) to a military couple, who are being relocated, who have an elephant nose they can't take with them, but they only want to give the fish to someone with experience with Mormyrids.
<Understood.>
I told them my experience was very limited (at best), but invited them out to see my tanks and talk with me about taking the fish. We had a nice visit and they loved my BGK (who chose to be very social for the occasion).
I explained to them that while I wanted their elephant nose, that I did not have time (or the energy) to properly prepare a whole other tank for the fish before they were going to be forced to leave (I have an empty 55 gallon, but it's dry, has no substrate, filter, or heater - I've just been storing it). Still, they seemed quite determined to get me to take the fish and suggested that it would be fine in my 75 gallon.
<Hmm...>
Well, my 75 gallon currently houses 2 rope fish, one peacock eel, and a 2 inch Bristlenose, and I just don't know if that group would be compatible for ALL the animals.
<Very difficult to predict. In terms of tank loading, not a problem assuming good filtration and regular water changes. The question is whether the Elephantnose and the Black Ghost will coexist. Ecologically, they occupy very similar niches so there will be competition for them in terms of swimming space, hiding place, food, and most importantly, electrical frequencies. This latter is the key here: if they jam one another, they'll irritate each other, and because the sense is electrical, not visual, you can't really "hide" them from one another by adding more rocks, plants, etc.>
I told them I believed the peacock eel also found its food by use of an electrical signal and I don't know if that would cause a problem for the elephant nose or the eel.
<I'm not aware of electric sense organs in Spiny Eels, but I could be wrong. If they have one, it'll be passive, like on sharks, simply able to pick up the electric signals caused by muscle contractions in prey animals; fish with active electric senses, like Black Ghosts and Elephantnoses, have distinctly "stiff" bodies so that the electromagnetic field is fixed, allowing them to sense the distortions caused by obstacles, rivals and prey. Much more sophisticated!>
I told them I wanted to help them, and that I wanted the elephant nose, but I wasn't going to sacrifice the current residents of my 75 gallon tank, the elephant nose, or my sanity by forcing this.
<Right.>
I've been researching since last night and can't find anything specific, both for or against, putting the elephant nose in with the rope fish and eel, so when they called me this morning, I told them I was going to write to you for your advice - if you thought it would work, I'd take the fish; if not, they were going to have to find someone else to take it. So, what do you think?
<I'd give it a shot *if* you had the option of returning the Elephantnose if they squabble. But if you're lucky, the two species will use different frequencies, and beyond territorial skirmishes, will ignore each other. I wouldn't bet the house on it, but it'd be worth a go, particularly if both specimens are still relatively small. Neither species is heavily armed, so aggression tends to be a slow burning sort of thing, with stand-offs and chases, rather than bites. So all else being equal, you can see if they're failing to get along, and act accordingly. Cheers, Neale.>
Re: Tough Decision to Make. Mormyrid comp.       6/15/17

I'm sorry, I should have been more clear. The elephant nose would not be going in the tank with the BGK.
<Ah!>
You see, (and you're going to think I'm crazy) I have 8 fish tanks up and going and although the tanks are not species specific, they are parameter specific.
<Sensible.>
I refuse to expect a fish to "adapt" to less than ideal parameters for that species just because I want it.
<Agreed; some fish are adaptable of course, but others will inevitably do poorly in the wrong conditions. You simply need to know your fish.>
I believe that each tank should meet the specific requirements of the fish I want to put in it. Therefore, the BGK has her own 72 gallon tank that she shares only with her Brochis catfish and one Bristlenose because they share the same parameters and the Brochis and the Bristlenose don't mind the extra current that the BGK needs (plus there are areas where the current isn't as strong).
<Quite so. Brochis are sadly underrated, but a much better choice than Corydoras in larger, deeper tanks. Things like Megalechis and Hoplosternum are good too, being even more hardy and a bit more robust, so good choices with adult oddballs that aren't actually predatory, just big.>
Even though the water parameters would fit the elephant nose, I still would not put that species in this tank for the reasons you mentioned plus the fact that elephant nose don't like a strong current.
<I think they're a bit more adaptable than you might think. Bear in mind that even a brisk aquarium current is barely a dribble compared with the flow in an African river! So provided there are resting spots below or behind rocks where they can rest, these sorts of fish should tolerate water flows up to 8-10 volume of the tank per hour. But yes, for sure they won't appreciate turbulent flow in open tanks without shelter.>
The tank I want to put the elephant nose is a separate 75 gallon that has only the two rope fish, the spiny eel, and a Bristlenose.
<Oh, he'd be fine here.>
It has a sand substrate, plenty of plants (the plants have a tendency to "move" as the spiny eel likes to tunnel through the sand), and plenty of caves to hide in. It has a Cascade 1000 canister filter which provides a pretty good current, so I keep the spray bar submerged to slow it down as the rope fish don't like a strong current either. That is the tank I was going to put the elephant nose in. The rope fish are 6 and 8 inches and the elephant nose is just under 4 inches, so I don't think I have to worry about them trying to eat the elephant nose (they haven't bothered the spiny eel and its about 4 inches as well). Plus, I feed only frozen foods (bloodworms, baby brine shrimp, daphnia, Cyclops, and chopped up grocery store fish or prawns) so hopefully that satisfies their craving for meat.
<All sounds good. Elephantnoses go wild for plankton, so your baby brine shrimps, daphnia and Cyclops should fit the bill nicely! Once settled they're pretty tough, even bossy, but these tankmates sound about right for them.
Good luck, Neale.>
Re: Tough Decision to Make      6/15/17

Many, many thanks! The couple that have this fish live on (or near, I haven't been to their home) Mountain Home Air Force Base in south central Idaho. It's about a 2 hour drive for me, but they were so excited (and I think relieved) when I just called them and told them you gave the "thumbs up" that they offered to meet me halfway in Boise.
<Cool.>
Their movers are coming this Friday to get the rest of their belongings, and they fly out on Saturday, so we've arranged to meet tomorrow when I can pick up the fish. I'm really excited, (ok, and a little bit nervous as I won't be able to return this fish if something goes wrong), and your comments have given me the confidence to go ahead.
<At the very least, you're giving this fish its best chance of a secure future. Keep us posted.>
Thank you for all you do!
<Most welcome. Neale.>
Re: Tough Decision to Make      6/16/17

Well, here he/she is! I hope I reduced the picture small enough for you to download. (lol) I'm sorry about the picture, but he/she wasn't in the mood to "mug" for the camera and this is the best I could negotiate.
<Not an easy species to photo, trust me!>
It's understandable though, he/she just spent the last 3 or 4 hours in a plastic butter tub driving in a car and then suddenly finds himself/herself in a whole new world.
<Quite so; this is an intelligent animal (for a fish, anyway) sensitive to its world. Give it time.>
Is this species always so thin?
<Nope. While the "stem" between the tail and body is thin, the actual girth of the body should be relatively chunky; Mormyrids are valued food fish in the wild. At the least, you want the belly area to be distinctly convex, and regular small feedings (even 3-4 per day) is a good way to help this fish put on weight. They have big appetites (perhaps something to do with their electricity production) and do need good quality food, and plenty of it. Daphnia, brine shrimp and the like are useful; if you can get them, clean wormy foods are excellent, perhaps Microworms but ideally small earthworms and the like. Tubifex and bloodworms definitely taken, but not without their risks.>
Is there a way to tell if its male or female?
<Probably, if you're another Mormyrid. Females are probably a bit more chunky when mature (commonly the case with fish) but they actually identify gender by using their electric sense, so far as we're concerned, they basically look the same. If you know any physics specialists with an oscilloscope, it's actually possible to hear their clicking with the right tools. Very neat. Cheers, Neale.>

Re: Got My First BGK; multiple Mormyrid stkg.      5/1/17
If you can stand yet another question from me, I was hoping you could clear up some information (or, possibly, misinformation) I found on the internet.
I have read that you cannot (or at least should not) keep more than one mormyrid in one tank.
<Does depend on the species. Some are quite sociable, and do well in groups of 6 or more specimens. Indeed, most of them probably are social in the wild, certainly the class Elephantnose seems to live in big schools, but the sheer size of the standard Elephantnose makes this very difficult to accommodate at home. Singletons can do well, becoming fairly tame if looked after well. A big group should be fine too, but unfortunately in twos or threes they tend to squabble unless the aquarium is very large, so they're rarely kept in groups outside of public aquaria.>
They say that the electrical impulses these fish use to find food would conflict and potentially cause both fish to starve.
<Correct. Dominant specimens hog the best frequencies, forcing weaker specimens to use less effective ones, making it harder for them to navigate and find food. Not a problem in the wild where a big school of them couldn't be dominated by a single specimen for any length of time, but in the aquarium, it can be a bully's paradise with so little space available for weaker fish to move out of trouble.>
I have no intention of getting any more BGK's, but I keep thinking about the little Elephant Nose. I'd love to have one, and their water parameters are consistent with the BGK, but I don't want to cycle up another tank right now.
<I would not mix Elephantnoses and Black Ghosts in the same tank, at least, not without a Plan B if it turned out the two species didn't get along.>
Also, I'm concerned that because the BGK comes from fast moving waters and the Elephant Nose lives in slow moving water, that the Elephant Nose would suffer in the same tank.
<Quite so.>
Again, this is not something I plan on doing in the near future as I have my hands full with the BGK. I guess you could say I'm just starting to research.
<Do review some of the smaller, more sociable members of both these groups. The Glass Knifefish (Eigenmannia virescens) for example is fairly widely traded, and small enough that maintaining a group in, say, a 55-gallon tank
wouldn't be impossible. Such a species could cohabit with tetras and catfish, if all were chosen with care. Similarly the Baby Whales (various Pollimyrus and Petrocephalus species) are smallish relatives of the Elephantnose that are viable in groups if you have the space. Cheers, Neale.>
Re: Got My First BGK     5/1/17

Thank you again! But I've got my heart set on an Elephant Nose.
<Understood.>
However, given your advice, I think its best that I just focus on the BGK for now and put off getting the Elephant Nose until sometime in the future when I'm able to set up a tank just for that fish.
<Wise. Although good community fish in the sense of cohabiting well with small African tetras and the like, their special food requirements do mean they're poor choices for rough-and-tumble set-ups alongside species such as
non-herbivorous catfish and loaches that might compete for food. They can be picky eaters, but not excessively so, and will adapt to a range of foods. I memorably saw an adult specimen consuming vast quantities of baby brine shrimp!>
Thank you so much for all you do!
<Most welcome. Neale.>

Xenomystus and Gnathonemus... stkg.; and tog.     1/22/16
I'm planning a 120 gallon for a group of elephant noses. I'm also considering a group of Xenomystus nigri, in addition to or replacement of the elephant nose school.
There is advice on your site about Xenomystus, that adults are territorial but not so much that it's impossible to keep a group.
<Can be if "crowded"; something like Mbuna cichlids...>
I also found a video of a public aquarium with dozens of adult Xenomystus, (it was much taller and bigger than a 120), they were active, and not avoiding each other. So I don't know what that says about their behavior in a smaller group and smaller tank.
<Ah yes; can be grouped here>
In a 120 gallon, how many Xenomystus could be added to a school of 10 or more elephant noses?
<About the same number>
Is their a similar approach with Xenomystus and Gnathonemus, keeping them in larger groups works and small groups leads to problems?
<Yes>
Or is Xenomystus less aggressive and a smaller group of 5 will live together peacefully?
<Not likely in this large a system... 2 or 3 would likely, or ten or more.
The Notopterids may well pose a problem of out-competing the Mormyrids for food>
Is a 120 with a group of both of these fish too crowded?
<Not likely; though incompatibility for food....>
And finally is it better to use a 4' x 2' x 2' 120 gallon, or the 60-72" long version that only has 18" of depth?
<For me, for these fishes, the longer and shorter... more bottom area>

Thanks, I don't know if combining these fish is best left to a tank bigger than a 120.
<Best to not combine, but use other, more mid and upper water fishes as tankmates IMO/E. Bob Fenner>
Xenomystus and Gnathonemus /Neale       1/22/16

I'm planning a 120 gallon for a group of elephant noses. I'm also considering a group of Xenomystus nigri, in addition to or replacement of the elephant nose school.
<They can coexist, given space.>
There is advice on your site about Xenomystus, that adults are territorial but not so much that it's impossible to keep a group.
<Quite so.>
I also found a video of a public aquarium with dozens of adult Xenomystus, (it was much taller and bigger than a 120), they were active, and not avoiding each other. So I don't know what that says about their behavior in a smaller group and smaller tank.
<Pairs and trios can be a bit unpredictable, but larger groups work better, especially in large tanks.>
In a 120 gallon, how many Xenomystus could be added to a school of 10 or more elephant noses? Is their a similar approach with Xenomystus and Gnathonemus, keeping them in larger groups works and small groups leads to problems?
<Correct; I'd not keep fewer than six of either, which 120 gallons should house perfectly well. A few more of either, as water quality and filtration allow, and of course depending on other tankmates, such as dither fish you think helpful.>
Or is Xenomystus less aggressive and a smaller group of 5 will live together peacefully?
<See above. Xenomystus may be irritated by the electrical signals produced by the Gnathonemus. So you want space, and I'd suggest a decent number of nice big ceramic tubes (or similar) where the Xenomystus can rest up, away from the Gnathonemus. There'll also be a fair amount of competition for food, and I'd definitely be getting youngsters that I could train to take frozen foods rather than older, more fussy specimens.>
Is a 120 with a group of both of these fish too crowded? And finally is it better to use a 4' x 2' x 2' 120 gallon, or the 60-72" long version that only has 18" of depth? Thanks, I don't know if combining these fish is best left to a tank bigger than a 120.
<Hope this helps, Neale.>

Mixing FW electrogenic fishes   7/12/08 Hi! ??? I have a 46 gallon, bowed front tank which is planted and contains many hidey-holes (small and large). About a month ago I purchased my first elephant nose fish and his roommate of one year, a single black knife fish (I love both fish and didn't want to separate them after so long together). <Mmm, problematical... electrogenic fishes often don't "mesh" signal, personality wise> They seem to be great "friends", first sharing the same clear tube and then moving to the same cave. I've read many places that since they are both weak electrogenic fish, they may stress each other. I don't know if I'm hurting them by keeping them together or if they are just not of the norm and actually are good together. <Mmm, well... if yours are getting along... a reminder to all: the "price" of freedom? A: Constant vigilance... a good spiel for these personal-liberty-stolen times> Another quick question, I was interested in getting more elephant nose fish. I heard more then 3, but I'm not sure if a 46 gallon will comfortably house 4 elephant nose. I heard both, that it is big enough and that it is NOT big enough and? I was looking for a reliable answer. Please help! And thank you in advance! ~Rachel <I would not mix more in here... Please have a cautionary, informational read here: http://wetwebmedia.com/FWSubWebIndex/mormyrids.htm and the linked files in order, above. Bob Fenner>

Elephant nose fish... sys., comp.    4/4/08 I was thinking about getting a ten gallon tank. I want to put an Elephant nose fish in the tank, some angel fish, and maybe a small bristle nose Pleco and/or some bottom feeders maybe some Cory cats or clown loaches. What do you think of this grouping of fish? Thank you. Nick <Hi Nick. In a word, NO! This combination of fish won't work. Starting at the top: Gnathonemus petersi is one of the most difficult fish in the hobby to maintain for any length of time. These things are non-negotiable: a sandy substrate, excellent water quality, live or wet frozen foods (bloodworms particularly), and no bottom-feeding tankmates. Most specimens starve to death, so you have to consider feeding carefully. Secondly, Angelfish and Clown Loaches and Bristlenose Plecs are all far too large for a 10 gallon tank. A pair of Angels might fit into a 30 gallon tank along with a few midwater fish, but Clowns need to be kept in groups (at least three specimens) and ultimately need tanks 55 gallons upwards. Both Clown Loaches and Gnathonemus petersi are super-sensitive to copper-based medications, and Gnathonemus petersi especially will be quickly killed by the standard anti-Ick medications. So before thinking about tankmates for this fish, you need to have a quarantine tank set up. For a 10-gallon tank, you really need to be thinking about small, inactive fish around the 1 to 1.5 inch mark. Shrimps and Nerite snails are also worth considering. If you're a beginner, steer clear of 10-gallon tanks entirely; they're difficult to stock and even more difficult to maintain. For inexperienced aquarists, the 20-gallon tank is the ABSOLUTE minimum. Hope this helps, Neale.>

African Knifefish with Elephant Nose... Ost. comp.     01/13/2008 I've read conflicting information in various media concerning putting African Knifefish with Elephant Nose fish. <Indeed?> I'm moving my 7" African Knife into his own 55 gal tomorrow and would like to know if I can put my two 5" Elephant Nose with him. <Possibly, but Elephantnoses do get a bit territorial, so make sure it has lots of hiding places. Xenomystus nigri isn't one of the Knifefishes that generates an electric field, but it is apparently sensitive to them. So while I doubt the Elephantnose will make a bee-line for the Knifefishes in the same way it does other electrogenic fishes, the Knifefishes might get annoyed by the electric field from the Elephantnose, and that could lead to tensions.> I know both fish have weak electrical fields. <Xenomystus nigri does not generate an electric field. Appearances aside, it belongs to the non-electrogenic Notopteridae Knifefishes, a different group to the electrogenic Gymnarchidae and Gymnotiformes, both of which contain true electrogenic species.> Several sources say you can mix Elephant Nose with African Knifefish but *not to mix them with Black Ghost Knifefish. A bit confusing because they don't say WHY. Temperament perhaps? <Black Ghosts -- Apteronotous albifrons -- are members of the electrogenic Gymnotiformes group, and likely when Elephantnoses and Gymnotiformes are mixed, the two varieties of fish annoy each other with their electric fields.> The 2 Elephant Nose bump into each other but I've not seen any aggressive behavior in the 2 months I've had them, they seem to get along well and were bought together from the same tank. <In theory, Elephantnoses are schooling fish, but in captivity they often don't get along. The reasons aren't clear for this.> All 3 fish are great eaters but I'd like to keep them separate from my other fish because I'm afraid they just wouldn't be able to compete for food in other tanks. <Agreed, though provided Elephantnoses are mixed with species that never take food from the bottom of the tank, they can be placed in communities. Hatchetfish, halfbeaks, Danios, African Butterflies and so on would work.> Would it be a reasonable solution to put them together? There will also be a 1 1/2" Raphael Catfish but no other fish. <Certainly worth a shot. I tend to recommend against mixing catfish/loaches and Elephantnoses because of problems with feeding. But if your fish are feeding well already, then maybe you'll be fine.> Thank you for your time, options & your dedication. Sincerely, Mitzi <No problems, and happy to help. Neale.>
Re: African Knifefish with Elephant Nose  01/14/2008
I'm going to go look (online 1st) for "The Diversity Of Fishes" and snatch up the 1st copy I find, thank you! You can't put a price on a good book that you can refer back to for many years, I love books. It fascinates me that if we give a fish what IT needs (physically, psychologically & diet-wise) that the other aspects fall together. <Hi Mitzi. Yes indeed... one of the nice things about keeping fish (compared with, say, dogs) is that it's relatively easy to create an environment so natural the fish will complete its entire, natural life cycle in captivity including social interactions, courtship, breeding, and brood care. Dogs, by contrast, are largely limited to being pets, and rarely get to interact fully with other dogs, let alone organise themselves socially.> Common sense should tell someone Elephantnose don't need any bottom feeding completion. The fish shop told me to put them with Loaches and feed only brine shrimp, I just roll my eyes at them most the time. <All too common. Most stores see them as oddball "scavengers", which they're SO NOT!> These 2 will eat just about anything. I had to get creative but I figured out that if I cut stringy chunks of any kind of meat or insect they'll devour it. <Try putting in a small ball made of aluminum foil; supposedly Elephantnoses find these "toys" fascinating!> All my tanks have zucchini or squash in them and they even mash their funny noses into that. I haven't figured out if they're eating or not yet-but it's sure fun to watch them! <Not sure if they're eating it, but perhaps. They do hunt mostly by olfaction, and only secondarily using electric field detection. Hence they "touch" interesting things with that chin barbel to taste it.> It makes me wonder if they can communicate somehow. <Yes. Communication in Elephantnoses has been much studied and is known to be extremely complex. Essentially, dominant individuals "monopolise" the best frequency, and lower status individuals have to use less desirable frequencies. Within the group, there's constant jockeying as fish try to use the best frequency (i.e., the one that offers best navigation resolution). Presumably, they also use electric signals to convey things like sex and willingness to mate.> One will find food and 1/2 a second later the other one will come shooting as fast as he can from the other end of the tank. Just like chickens. <Hah!> I can't wait to find that book-thank you so much! Mitzi <There's quite a big chapter on electricity in fishes; it is a unique sense that fish have but no other vertebrate (something to remind those annoying "warm, fluffy animal" chauvinists! Enjoy, Neale.>
Re: African Knifefish with Elephant Nose  01/14/2008
Food for thought here. There was much you told me that I honestly didn't know. I don't know where else I'd have found such specific information (which is why I pick your brain often). I wish I had access to some sort of a "fish library" like the medical library we have. I'd be in heaven. <Hi Mitzi. If there's one book I'd recommend for anyone interested in fish beyond merely keeping them alive in a glass box, that book would be 'The Diversity of Fishes' but Helfman et al. It's a university-level text book, but so well written, and with so many diagrams and photos, that I think anyone with even a mild interest in how fish work and what they do will find it a fascinating read. Not a cheap book (I think I spent about £50 on my copy ten years ago) but should be accessible through libraries or used book stores if you don't want to pony up for the new edition. But trust me, once you've taken a peak, you'll want your own copy... it's that good!> I did move the African Knifefish & his little Raphael Catfish yesterday as planned but did *not put the 2 Elephant Nose in there, it didn't feel right to do so because the Elephant Nose are such busy bodies. <Elephantnoses are exceptional fish in many ways, and great fun once you understand their needs. They are among the very few fish for which scientifically accepted "play behaviour" has ever been observed, implying a level of intelligence well above what we normally associate with fish.> I didn't want Wendell the Knifefish to be stressed with all that activity. After reading what you had to say I'm glad I held off. <Cool.> The Elephant Nose have been in a 3 ft tank with 10 Hatchets and I guess they'll stay there until the aquarium fairy brings me a bigger tank for them. <Sounds as if he's happy. You seem to have figured out that elephantnoses do best with surface-dwellers. Good call.> Thank you, Neale. You've no idea how much I appreciate you. <Not a problem.> Mitzi <Cheers, Neale.>
Re: African Knifefish with Elephant Nose  01/14/2008
So much I didn't know about the Elephantnose-even after all I thought I'd read. <Always the way!> I found the book and ordered it on Amazon.com. I'm so excited :-)) My birthday is Jan 15th so it's a birthday present to myself, I can't wait to get it! <Hope you will enjoy.> I actually do understand the interactions of dogs, to a certain extent anyway as mine are all spayed or neutered. Dogs were my "1st love" as far back as I remember. People seldom understand why I 'want' a dozen dogs in the house but then they don't understand my fascination with a dozen aquariums either. I see & understand the interactions between the dogs, I can tell at a glance what each dog is portraying to another, why they're doing it and how to either stop or encourage the behavior. The dogs know the 'leader' is the short blonde lady with the aquarium hose-ha! <You "get it" -- Dogs are happier when kept in groups of their own kind, not just with people. At the very least, it's so much nicer for a dog when you take it on walks with someone else's dogs too, so that they can make a little "pack" and go do their thing, instead of always following the Two Legs about.> Sorry to take up your time, but I learn so much from you and maybe what you write will help someone else with these same kind of fish. <Who knows!> Thank you!! Mitzi PS I'll try the aluminum foil with the Elephantnoses. It'll give me and the Hatchet fish both something to watch :-) <Let me know what happens. Have read this, but never seen it. Cheers, Neale.>

Parrot fish with Mormyrus tapirus (freshwater African dolphin) 01/08/2008 hi- I needed some advice on compatibility between the fish in my tank. <Ah, these questions always bring up a question of my own: Did you research the fish BEFORE buying them? Investing in a good aquarium book is one of the best things you can do.> I started up a 55 gallon tank about 6 weeks ago. once the tank was set up, I added three parrot fish. A week later, I added two dwarf Gouramis. <Already bad. Parrot Cichlids are nasty-tempered Central American hybrid cichlids; Dwarf Gouramis are small, shy labyrinth fish that are easily bullied and extremely likely to die anyway because of Dwarf Gourami Disease.> Then, a week later, I added a black ghost fish and a Mormyrid (freshwater African dolphin). <African Dolphins can be a variety of things, but typically Mormyrus spp. Do bear in mind these fish are territorial (in aquaria at least), very difficult to feed, and a major challenge for even the most experienced aquarist. Some get extremely large. Do read here: http://www.wetwebmedia.com/FWSubWebIndex/mormyrids.htm and linked articles. Black Ghost Knifefish, Apteronotus spp., are only marginally easier to keep but still get large and remain a major challenge for anyone. Do see here: http://www.wetwebmedia.com/FWSubWebIndex/bgkfaqs.htm for more.> The pet store, (The owner of which gave me advice on all the fish,) whom I had bought all these fish from, did not at any time that I would need to buy different food for some of the fish. <Uh-oh.> This seemed odd to me, so I went online about a week after buying the dolphin fish and black ghost and read that the dolphin needs meaty, preferably live food. <And neither can really be kept together. They are both territorial, electrogenic fish that will view each other as, at the very least, an annoyance. So unless your tank is in the 1000s of gallons, these are fish best kept apart.> He also looked thin to me. In a panic, I went out and bought some frozen bloodworms. I have been feeding them to him for the last four nights. My concern is that he may not be eating enough. <With Mormyridae for certain, and Knifefish ideally you MUST quarantine new stock separately. Once feeding and tame, then move them to the show tank.> The parrot fish, from what I can see, seem to bully him and he is very shy. <Cichlids are incompatible with Mormyrids really; at least, big cichlids are. Once settled in and feeding, you can keep Dwarf Cichlids with Mormyrids easily enough.> I think they may be eating the food, despite the fact that I feed him in the pitch dark. <Both these fish prefer the darkness. They forage at night, partly by smell, and partly using electrical fields a bit like RADAR.> I should add that I have two hiding spots in the tank: one ghost tube, that is not in use as the black ghost fish has taken up residence in the sunken ship. I plan on buying a cave for the dolphin fish but are my attempts in vain? <Define "vain". If cared for properly these fish can do well, but you really do have to work hard at this. If you can't be bothered, and treat it like a Plec or Guppy, it'll die, sooner rather than later.> Are the parrot fish too much for him? <Yes.> Can this be remedied with more hiding spots? <Possibly, but don't bank on it. Depends on the size of the tank. In a 200 gallon tank with tonnes of caves (i.e., rocks everywhere, so the bottom of the tank is a maze of hiding places) the Cichlids might simply not be able to see or attack the Knifefish or the Mormyrid. But anything less that this is probably a waste of time.> I also keep the curtains drawn during the day as I know the BGK and DF prefer this. <They actually don't care all that much, having pretty poor eyesight. What they want is a tank with lots of 3-D hiding places and lots of plants as well (plastic are fine). Mormyrids live along rocky reefs and among the vegetation in rivers and lakes; Black Ghosts live in deep water at the bottom of major river systems among the rocks and dead wood. Neither spends much time in the open, at least, not by day.> Thanks Micaela <Hope this helps! Neale.>
Re: parrot fish with Mormyrus tapirus (freshwater African dolphin) 1/9/08
thank you for your response. I know now better than to simply ask a fish store owner about compatibility, but to do the research myself. I will be returning the dolphin fish to the store. <Sounds the best plan of action. Good luck, Neale.>

Longnosed elephant fish Dear Mr. Fenner: I would like to put elephant fish <will assume we're discussing Mormyrids> into a 10gal tall aquarium, but I have read many different opinions on this fish. I would like to ask you about them. Are they aggressive, or calm?  <Not aggressive, as in "mean" toward other fishes, unless they are very small... but not "calm" in the sense that they do move around quite a bit at night time...  I would like to have four (4) elephant in this tank. Would that be ok?  <Hmmm, actually, no... at your prompting, I'll place a piece I wrote and revised some time back... and images on the freshwater part of the website: www.WetWebMedia.com... look for it tomorrow... You want just one of these fishes in such a size system... they're electrogenic... don't care for being crowded with other such fishes> since I was told that they like to be in schools.  <In the wild, yes> Does four make a school? Also what kind of bottom should I have, gravel or sand, have read both, or doesn't it really matter. I believe these fish are bottom dwellers, and if this is correct, could I put another type of fish with it?  <Yes on all counts> If that would be ok, what kind of fish would you recommend. I have another tank with just Cichlids in it, and I know that I would not be able to mix them. <Other African animals from the same region would be my suggestion. Use Fishbase.org for help here perhaps... Otherwise, "community" fishes that aren't "mean".> I appreciate your help with this matter. Thanking you in advance for any and all help and advice you are able to give me. I am just a beginner, and want to learn the right way to do things. Thanks again. <Glad to help you. Bob Fenner> Sincerely, Shirley

Mormyrid Madness Hi, I have a Dolphin which is in the same family as the (elephant nose) fish. I have attached a picture of what it looks like. <Mormyrus tapirus> I have had it for about 7 months. I have it in a 75 gallon in with 5 Angels and 3 Discus. The aquarium is by a window but we have really thick blinds and we keep them closed. The aquarium doesn't receive direct light. I keep up with regular water changes. I have well water with a softener. My ph is high (about 8) but consistent. The temp is at 80. The nitrate is in the safe, the Nitrite is at the higher side of the safe levels but it may be because I have been feeding more lately. <Sounds like it might be time for a better test kit.  Please consider anything above zero as harmful, for nitrite; there really is no other "safe" level for this.  Nitrate is of much less concern, as long as it's not terribly high, it's okay.  What is your ammonia level?  Be sure to check that as well.> I feed at night, first a little flake to the Angels & Discus, then I feed either frozen Bloodworms, live Blackworms, or occasionally their favorite earthworms. <All good> They have all been doing really great except for just recently. About 2 months ago I noticed the Dolphin started going up to the other fish and it looked like it was rubbing it's nose/mouth on them. He started chasing/bugging them more and it has only got a lot worse with time. It has got so back that he will not leave the Discus alone. The Dolphin messes with them so much that the Discus have white marks on there sides and there fins are in bad, torn up condition. The Dolphin bug them so much that the Discus stay in one corner up at the top of aquarium. <This is *very* bizarre; this is a normally quite peaceful fish - it seems you ended up with the exception to the rule here.> I thought maybe if I feed them more the Dolphin wouldn't bother them so much. I started feeding twice a day. I also cut the hours I keep the hood lights on from 12 hrs down to 8 now thinking maybe this would help. Nothing has worked. I don't know what to do... My Discus must be very strong as I can't believe they are still alive with the stress they are put under & the condition they are now in. I don't think they will be able to hold out long. <They do sound pretty bad off, indeed.  I would be, too, in their situation - I don't much like my pals biting me ;) > I hate getting rid on my Discus but don't what them to suffer. I don't notice the Dolphin bugging the Angels quit as much as the Discus but I don't know if it will get worse if I remove the Discus. <It sounds to me like your best bet is going to be to remove the "problem" fish.  I don't think this bizarre aggression is going to subside.  If it were me, I'd keep the discus and either house the Mormyrid in a different tank or find it a new home.> Could you please let me know any suggestions/help you may be able to give or referrals? <You could *try* removing the Mormyrid to a separate tank for a week or two, let the discus recuperate, completely redecorate the tank, and reintroduce the Mormyrid.  I wouldn't hold high hopes of this working, but it's worth a shot.  You could also put a divider in the tank, giving the Mormyrid his own space and keeping the discus and angels safe from harm.> I would very much appreciate your time. Thanks in advance,  Robyn <Hope all goes well with your little pal - good luck!  -Sabrina>

Elephant vs. Parrot Hello, <Hi, Don here> We added an elephant nose to our tank about a week ago. He quickly found his shelter in a flower pot and has seemed happy. Last night (and maybe before but we hadn't seen it) he began exhibiting some aggressive behavior towards some of the larger tank mates. He totally ignores most unless he bumps into to them while rooting around for dinner. We have two parrot fish about 3 years olds. Last night he seemed to be attacking them. One was in another flower pot and had no trouble defending his territory. The EN seemed to be attacking the larger parrot who was hanging out mostly towards the top. He would swim along feeling with his trunk and a couple of time I found him up in the gills of the parrot. <This does not sound like an attack, more like probing for food. EN do have an electrical sense, but it is not strong enough to kill. Was he ramming, or trying to bite?> If this was an intentional attack it was very cunning and probably shouldn't be a surprise. <I would be. Smart fish, but not smart enough to reach in and rip out the gills> But I thought that the EN were only aggressive to their own kind. <My understanding as well. But each fish has their own traits. You can not always predict how some will react> The parrot was dead this morning. <Sorry to hear> What I am now trying to figure out is if the EN killed our parrot or if the parrot was on the way out the door and got a little push. The parrot was fine until dinner time last night and refused to eat and had lost his brilliant orange color. The EN could have been attacking him for a couple of days and weakened him. He did eat the night before and thought he ate yesterday morning but not entirely positive. He typically is the last one we had to worry about eating. Any thoughts on whether I have a fish eating EN would be helpful. If he is going to work his way through my tank until he is the last fish standing, he might be finding a different home. <Being more active at night, it's hard to say. From your description of the interaction you saw, I'd say "no". But who knows what was going on in the dead of night. A few other points. You do not mention if you Qt'd the EN. Possible he brought something in with him. Also possible that adding him taxed your bio filtration and you had a small ammonia spike. Either could be fatal to a stressed or weakened fish. Finally, what do you feed him? They are fond of small worms and such. If you changed or increased feeding when you added him, it is possible that is also taxing your filtration. Please check your water for ammonia, nitrite, nitrate and pH.>   I have seen many questions about the black spots appearing on parrot fish. In the three years I have had them, I noticed the black spots were great indicators of water quality and stress (this may have been answered and I missed it). It is not a disease. I know the first time we had it, I ran around reading about it but a quick water change and they were cured overnight. No medicines are needed. <Good to know. Thanks for passing this along> I don't support the way the fish are produced and sold but once they are home they should be well cared for. <Agreed, but will add that buying this fish only results in more being produced. Same with "painted" fish. Cruel as it sounds, if they were left to die in the fish store the manager would not order more. But you are correct in saying that once you have them you must give them the best of care.>   Thanks Dan

Elephant vs. Parrot Thanks for the reply Don. <My pleasure> The water quality is stable. The tank is a 90 gal tank with Emp 400 and hot 250 filters. <Seems great, but...>  Ph 7.2, ammonia .25 (always the same reading)<...if you always have ammonia you are underfiltering for the bio load in the tank. Or you have a bad test kit. Take a sample to your LFS and have them verify.> and zero nitrites. Nitrate .2 as well. <I assume this is 20ppm? If really .2, or even 2.0, I doubt it would show on your test. Anything below 20ppm is great. But lower is always better.> 1 lg. parrot (was 2), 6 small Cory's, 2 SAE's, 3 blk skirt tetras, 3 red tetras, 7 dwarf neon rainbows, 1 clown Pleco, 1 brushy Pleco, 1 Elephant Nose (EN). We feed flakes in the morning and then frozen food at night with some blood worms after dark for the EN. We didn't really change the amount too much just the timing of the feeding. So far the Cory's clean up what is left by the EN, if not we remove any excess. <Yeah, but what the Corys eat will still become waste. Removing is the key, uneaten or digested. What is concerning me here is that .25 ammonia reading. If verified then you need to reduce the bio load or add more bio filtration. More likely this is the cause of the Parrots problem than the EN killing him, IMO. Adding the EN may have been just the last straw that raised your ammonia production over the ability of your filters to convert it. Another possible source of the ammonia is old fish waste in the gravel, under rocks, in caves, etc,. Removing the ammonia will do more for your tank than removing the Elephant Nose. If you can add another 400, I'd do it. In fact, I have. I run two on a 55 gallon Pleco tank.>       Last night I noticed him going after our other Parrot (last one for us.) The parrots have large gill openings and he would run along the body with his snout and the enter the gill opening and appeared to be trying to wiggle through with some force. I am still not sure if this is caused by his poor eyesight and if he feels a hole he must enter or if he is trying to do damage to the fish. I cannot see if he is actually taking bites of the gill tissue but he is far enough in. I may have a mutant EN on my hands. <I still think this is more of a feeding activity than aggression. In the wild he would probe all the little nooks and crannies in his area looking for worms. I would think a dead or dying fish would be a good hunting ground. But all this is just a guess on my part. I have never seen this behavior and can find not mention of it. Don>   Thanks Dan

Double trunk elephant nose 7/12/05 Dear Sir, I found your publication regarding elephant nose fish online at http://www.wetwebmedia.com/FWSubWebIndex/mormyrids.htm I was hoping you could answer a couple of my questions. I recently bought a "Campylomormyrus rhyncophorus" aka Double trunk elephant nose fish. I am building an African tank (72g) and I am trying to stick mainly to west Africa. Upon releasing my new elephant nose in the tank he was immediately attacked by the Buffalo head cichlid who also inhabits the aquarium, he was able to remove a large section of the elephant noses lower back fin. I immediately placed the aggressor in quarantine. My question to you is how will this fin damage effect the fish (will it effect his electro navigation), and is there anything I can do to help? <Am hopeful the Mormyrid was not "too" damaged, traumatized... the family's members do have remarkable powers of regeneration... should otherwise regenerate the last bit of its tail> Also its difficult to find information on the double trunk species of elephant nose online, do you have a good references? -Mike Schulz <Only pet-fish ones that are hard to find/reference at small libraries. Have you tried "Google Scholar?". Pretty much all that is written re the family itself is pertinent to the husbandry of this species. Bob Fenner>

Mixing mildly electrogenic fishes... BGK and Mormyrids together?   5/27/06 <<Tom>> I was wondering if its possible to house a black ghost knife fish with a baby whale? My mum fell in love with one at our LFS. The tank is a 70 gallon planted discus with two canister filters going strong, and regular partial water changes. <<First of all, I'm assuming we're speaking of the Knifefish here. Very cool fish! To answer your question, this shouldn't be a problem as long as you have hiding places available. Your tank is certainly of sufficient size to very comfortably house this animal and I highly doubt there will be any serious territorial disputes going on. I hope you and your Mum enjoy your new pet, Jarryd!>> Thanks for your time, Jarryd <<You're most welcome. Tom>>

Mixing Apteronotids and Mormyrids... not advised   6/3/06 Hello,       I recently sent an email to you guys in relation to keeping a freshwater dolphin in a 70 gallon planted discus aquarium. I received a reply of yes but forgot to add that I have a 15cm black ghost knife. I am aware that the ghost has a form of electrical field and was wondering if his and the freshwater dolphin will fight???? <Too likely, yes> I would also like any opinions on whether its possible to house 2 black ghost knives together? I would buy 2 smaller ones of the same size and house them in a large tank with plenty of logs and hiding places) Have you ever heard of anyone doing this successfully? <Yes... in very large systems of consistent low pH, alkalinity...> I just love this fish so much that I would have 20 of them if I could!!!!!  One more thing, how long will it take my black ghost to reach adult length. <A few years> thank for your time! Jarryd <Bob Fenner>

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: