FAQs on Mormyrid Fishes Selection
Mormyrid Behavior, Mormyrid Compatibility, Mormyrid Systems, Mormyrid Feeding, Mormyrid Disease, Mormyrid Reproduction, Bony Tongue Fishes, Electrogenic Fishes,
Aba Aba Knifefish,
African Butterflyfish, Arapaimas,
Featherfin Knives, New World Knifefishes,
Mormyrids... Stocking tog.,
If Mormyrids are crowded, does this bring out a different behavior that
is sustainable and can they put up with the presence of many other
Mormyrids in close proximity without being stressed by each others
<Does seem to be the case in retailers' tanks'¦ but
whether sustainable long-term at home, I cannot say. Would not
recommend overcrowding any fish as sensitive as these.>
Does this video show there is a benefit to crowding them, and they are
adapted to put up with large groups of their own kind, like with
<And even with Tropheus, there are huge problems with
The person who has that tank said that out of the Mormyrids he has
Campylomormyrus tamandua is not very aggressive in groups, is that well
known to be true?
<The species is not commonly kept, so it's hard to say. Baensch
describes them as "peaceful loners" and comments that in
groups bigger ones bully the smaller ones, preventing feeding. So your
problem may be a long time in coming, with fish seemingly coexisting
for weeks, months until the weaker ones starve.>
Also wonder what the guidelines are for Petrocephalus, they are
schooling and small so how much room and how big a school is needed to
keep them. And they still need pvc pipes to hide from each
other? Is a 3' tank too small for a school of Petrocephalus,
will they eventually breed and kill each other in that size tank?
<Would treat as any other medium-sized, delicate schooling fish,
such as Glass Knifefish. Oversized tank, oversized filter relative to
their size. Get the tank up and running for some months before
introduction. Maintain with peaceful tankmates selected to play the
role of dither fish (surface-swimming Rasboras or Danios for example)
rather than anything midwater or benthic. A tank upwards of 55 gallons
with a filter rated at not less than 8 times the volume per hour would
seem prudent. As with all Mormyridae, the more caves, tubes, robust
plants the better. Although gregarious, that doesn't mean this
species "likes" its own kind -- just as with any schooling
fish, even Danios, the stronger will be bullying the weaker, albeit
rarely to the point of death. Rather than keeping 6, aim to keep 10 or
Re: Mormyrids 2/9/12
Why are Mormyrids so sensitive to chemicals and metals, in a way most
other fish aren't?
<They just are. All fish are sensitive to copper and formalin and
But some are more sensitive than others, and Mormyridae are at the very
sensitive end, like Stingrays.>
I know they're stress prone and aren't treated properly
usually, but the water issues, is their one trait that makes Mormyrids
so frail in that way?
<Pretty much everything about them is demanding.>
The article on them on WetWebMedia says to treat tap water and let it
stand for a weak, ideally. Is there a tap water test to tell you if
your tap water is likely to kill them?
<Water chemistry actually doesn't matter much. So your issues
are ensuring copper and ammonia are neutralised, as well as the usual
chlorine and chloramine. Mormyridae aren't killed so much by bad
water as bad water quality.>
It seems like there are many possible ways for that to happen, so
I'm curious as to why.
<Just is. Cheers, Neale.>
Re: My first aquarium... Bichir hlth.,
Mormyrid sel. 12/28/09
My bichir has developed a white mossy growth covering much of his
The rest of the tank seems fine. Is this the Ich I hear about?
<No; is likely Finrot and/or Fungus. Treat promptly but with great
formalin and copper-based medications can be lethal to Bichirs,
Mormyrids, Catfish and Loaches.>
I have a baby whale in the tank along with a Featherfin catfish and the
<"A" Baby Whale (Pollimyrus sp.) won't last long...
these are highly gregarious fish that should be kept in groups of at
least five specimens. Singletons tend to pine away, while groups of 2,
3, or 4 often end up with one bully and the rest dead... and of course
the remaining bully ends up pining, so then there are zero. Do always
read up on fish prior to purchase.>
Many thanks for your help.
Re: My first aquarium
Ouch I tried but came up with little info.
<Often the case with fish that have a poor survival record in
While books (and, if I might modestly add, expert fishkeepers like me)
will usually have something to say about Mormyrids and other
"difficult" fish, online sources put together by the vast
majority of hobbyists concentrate
on fish species that are relatively easy to keep. Instead you need to
pick up a copy of something like Baensch's Aquarium Atlas volume 3
you'll find Pollimyrus listed and briefly described.
What kind of timeline does he have?
<Really does depend. A single specimen may well thrive if tankmates
are smaller than it is, and it can feel settled and secure. But with
tankmates of similar or larger size it will feel more nervous, and the
more nervous it is, the more stressed it can become.>
I don't know if there are four more in the city. I've been
He is eating well right now.
<Good. With Mormyrids generally, while eating well, they're
basically healthy and easy to keep; but as soon as they have problems
getting enough to eat, their condition worsens, and they become much
weaker. Good water
quality, including a high oxygen concentration, is important.>
I have purchased a "naphthoquinone" based product. Will that
PS: do you guys take donations? I'm starting to feel like a
<Yep, you're welcome to buy us a beer. Do see the Donate button
at bottom right.
Don't worry about feeling like a pest; this site works precisely
because we get lots and lots of interesting questions. Besides, we
aren't selling anything, we're all volunteers, and we really do
want to help. Cheers, Neale.>
I have a
question concerning convict cichlids comp. and elephant nose sel.
01/21/2008 <Ask away.> Ok... Are elephant noses hardy fish?
<Not even close to being hardy. Among the most difficult freshwater
fish commonly traded.> What is the minimum tank size for one? <On
its own, likely around 150 l/40 gallons. They get pretty big if kept
properly. In a community setting, much more space is needed, because
they are territorial and their electric field does irritate some
fish.> Also, do they need to be put into groups, I was planning on
getting just one. <Elephant noses are best kept either singly or in
groups of six or more. In twos and threes they tend to be
unpredictable, and sometimes quite nasty to each other. Wild fish do
live in schools though, so singletons are, unsurprisingly, rather shy
(i.e., you don't see them most of the time).> My other question
is, are convicts really that aggressive, because I have friends who own
these and they say they have had success keeping it with zebra danios.
<Define "aggressive". Yes, Convicts are (for their size)
very aggressive towards anything they deep as either a rival for
nesting space or a potential predator on their offspring. So despite
being relatively small cichlids, they are best kept in (big) community
tanks that only include larger cichlids, such as Jaguars and Red
Devils. On the other hand, in a spacious enough aquarium, Danios might
well be ignored. The use of Danios and other surface-living fish has
been widely documented among cichlid-keepers as sometimes beneficial.
Such "dither fish" as Danios encourage the bottom-dwelling
cichlids to stay out in the open more. So would such a combo work?
Quite possible. Is it a good idea for the less experienced aquarist?
Probably not.> From your experience, are they really aggressive?
<I've kept Convicts in a 200 gallon tank with a Red Devil, a
Jaguar Cichlid, some Firemouths, a Channel catfish and a Gar. They all
got along fine. Read from that what you will, but I'd make the
point that the Convicts were holding their own in a big tank filled
with potentially aggressive and/or predatory tankmates.> Will it be
fine to keep it with n elephant nose? <Absolutely not.> Thanks
for your time and thank you for your help. <Happy to help,
"Freshwater dolphin" too vague...
(Mormyrid search) I think I've fallen in to the trap of
"common names" being used among those who don't know the
difference (myself included). <Easy to do> I have been looking
for a M. tapirus and as of late had little luck. <The
"Western" Dolphin... don't think I have ever seen this
species offered in the West (the U.S.)... comes out of Cameroon and
Guinea... sometimes imports from here are offered in Germany, other
European countries> However, I was speaking with a LFS as he
received his weekly "list" and he said "oh, I can get
the freshwater dolphin you've been wanting". I
replied "oh really, the M. tapirus", he says, "uh, yeah,
sure, it's the Mormyrus dolphin". Well, I asked to
verify, we looked up a picture and I chanced it. The fish
will be in later this week and I'm now thinking it may be a M.
longirostris. It seems these two species are very similar
and even both are commonly referred to as a freshwater
"dolphin". <Yes... the "Eastern" Dolphin is what
is primarily seen in the United States> It also seems
the M. long. is much more common than the M. tap. and therefore
that's why I think it's not the tap. Any thoughts?
<Pertaining to what?> I've looked hard for information on the
both of these, trying to find enough info to ID my potential
specimen. I use fishbase.org a lot and, based on my
findings, there, I do believe the tap. is the one I really
want. I'll gladly send a pic and more info once I
receive it. Any insight would be most
appreciated. I would feel badly not taking the specimen he
gets in, but I also don't want to be misinformed as to what species
I actually have. In search of M. tapirus... Sincerely, Dana Irby
Hendersonville, TN <Perhaps a trip to Africa? Or to Germany? Bob
Mormyrid search Thanks for your
reply. From your comments, it sounds as though the M. tap.
is not available here in the U.S. so I guess it really doesn't
matter what they call it here...it's most likely M. long.
<Yes> Sorry for being so wordy and vague about what I was wanting
from you. Ultimately, you answered my question and any further
questions regarding M. tap. would be a mute point anyway. <No
worries> I'll just see what happens. Thanks again and have a
wonderful day!!! Dana Irby <You as well. Bob Fenner>
Do you know where to get freshwater
dolphin (Mormyrus tapirus) <Sorry, no. I have seen them at a few
Fish/Pet stores. I did a search on Aquabid.com, but none listed right
now. Check with the manager of your LFS. Many times fish will show up
on his venders list, but are not ordered. He may be able to get them
for you. Don> Sky McDougal
The Elephantfishes, family Mormyridae, In
Aquariums - 03/14/2005 Just wanted to share my pictures
of my Elephantnose. I found your article while trying
to do some research on them. Very hard to find any
information. Hope you enjoy them. <Mmm, didn't
"come through"... can you send these as jpg
attachments? Will post with credit to you. Thanks, Bob F>
Lesley Moravick #3 the last picture. I hope you get
them. I just love my guy. I have had
him/her for 2 years now <Very nice. Thank you for sharing. Bob