FAQs on Mormyrid Fishes Foods/Feeding/Nutrition
Mormyrid Compatibility, Mormyrid Selection, Mormyrid Systems, Mormyrid Disease, Mormyrid Reproduction, Bony Tongue Fishes, Electrogenic Fishes,
Aba Aba Knifefish,
African Butterflyfish, Arapaimas, Arowanas, Featherfin Knives, New World Knifefishes,
Elephant Nose Question; gen., fdg.
My Elephant Nose lives in a 75 gallon tank with 6 Congo Tetras (all
female) and a Bristlenose Pleco. The tank has a Cascade 1000 canister
filter on it and I made sure the tank was cycled before I put any fish
in it. I test weekly and have never had any ammonia or nitrite, weekly
water changes keep the nitrate around 20 ppm or lower - and I've never
had a problem (knock wood) with this tank. The substrate is pool filter
sand, temp is 77 - 78, kH is 6, pH is 7.4, and the tank has lots of
plants (real and fake) and caves so he'll feel safe. I feed flake food
for the Congo Tetras, bloodworms, brine shrimp, and Mysis shrimp for the
Elephant Nose, and algae wafers for the Pleco.
<All sounds lovely, Renee.>
The Congo Tetras eat from the top or mid-range of the tank and the Pleco
is almost always "suckered" to the side of the tank, so I'm sure the
Elephant Nose is getting all of the food I put in for him. Also, he has
never shown any interest in any plant based foods and will diligently
work to push algae wafers that float down on his favorite side of the
tank (the left) back over to the opposite side.
<Quite so; these are more or less carnivores in the wild, albeit on
But tonight I realized that even though I've had him for almost 2 years,
he really hasn't grown very much. The information I've found online is
vague or varied (some sites say this fish reaches an adult size of 4
inches and some sites say 9 inches), so I wanted to ask your opinion; is
this species just normally slow growing or could he be missing something
in his diet or environment that's slowing growth?
<They are slow growing, but they do also have substantial appetites, and
it is easy to underfeed them. Healthy specimens should have a gently
rounded abdomen and I'd suggest they do better with many small meals
rather than a single big feed. So far as food variety goes, your
selection sounds fine.
These are not particularly fussy fish, especially once settled, and
settled specimens will sometimes even take flake food, though most do
prefer frozen and live. Do remember frozen and live foods are mostly
water, and therefore less filling, than flake, so it's easy to underfeed
fish fed solely on such items. Nonetheless, given yours is some years
old now, you're probably doing fine, so apart from maybe upping the
amount of food it gets per day, there's nothing much I'd suggest
changing. Cheers, Neale.>
Re: Elephant Nose Question 7/31/18
Great! Thank you!
<Glad to help. Neale.>
Re: Tough Decision to Make. Mormyrid fdg.
Not hollow bodied, just straight as a board without any roundness
<Does sound undernourished, yes.>
He looks like a ribbon. He does appear to be actively feeding as I see
him out after the lights are out seeming to be foraging. And I'm feeding
once in the morning (where I squirt the Cyclops, daphnia, baby brine
shrimp, egg yolk mixture right into his cave), then around noon, again
at 6pm or 7pm, and once more just before I go to bed.
<I would up this; multiple small meals better than one/two big meals --
fish have (mostly) short digestive tracts that cannot contain much food,
so there's a risk that surplus food is passed straight out. As with baby
fish, anything up to 6 meals a day is perfectly viable -- think snacking
rather than gorging, and that's the optimum for most generalist fish.>
The videos I've seen of this species show this fish coming out
immediately to the owner in response to food.
<Once settled, yes, they do this.>
My fish doesn't do that (at least not yet.) He just seems to come out
when he decides to come out and look for food when he decides to look
for food.<Needs time to settle in!>
The fish in the video are obviously much more robust than he is, yet
they behave as though they are hungry.
<This species always seems hungry; as noted previously they have big
He's barely the width of a ribbon folded over two or three times and his
sides are flat as a board, so why doesn't he behave as though he hungry?
<Recognise this species is nocturnal and shy. They're also very social
in the wild. So singletons are stressed until they learn they're
somewhere safe. Take it slowly. Feed with the lights out, and offer
irresistible treats like worms and baby brine shrimp. Frozen lobster
eggs are good choice for fattening up fish, if yours will take them
(most fish will).
Regardless, be patient. Cheers, Neale.>
Re: Tough Decision to Make 6/18/17
Ok, I got the fish eggs. They are San Francisco Bay Brand frozen fish
eggs and the package says the type of eggs are Capelin (Mallotus
<Not used these. No idea if they'll be taken, but worth a shot!>
I got home, rinsed them in tank water, and put them in. No one seems
overly excited, but I turned off the tank lights, closed the drapes, and
after about 15 minutes, the elephant nose came out to forage.
Now I'm going outside because I'm afraid I'm stressing the fish out with
my fussing and fretting. I'm telling myself that I'm doing everything
that can be done and its up to the fish now.
<Quite so. Allow time to handle this; Mormyrids are reticent feeders
until completely settled in. Cheers, Neale.>
Re: Tough Decision to Make 6/18/17
I've called the two different aquarium stores in my area, and neither
carries lobster eggs, but they do carry frozen fish eggs - would those
work as well?
<Possibly; my fish certainly eat lumpfish caviar when it's offered!
Worth a shot, but don't spend a lot of money on such alternatives.
Worms, crustaceans, and especially insect larvae are the main foods of
Re: Tough Decision to Make 6/18/17
Thank you so much for your patience and help!
<No problem! Neale.>
Re: Tough Decision to Make... now fdg. BGKs
Ok, will keep going with the daphnia, Cyclops, baby brine shrimp, and
I'll chop up blood worms for him (those are the only foods besides the
processed flake or pellet type foods available in this area). I'll also
boiled egg yolk (problematic and messy, I know) but it did seem to give
the BGK a boost.
<Indeed; an old-timey source of nutrition for baby fish, picky fish of
all types. Best used a few hours before a water change though, unless
used very sparingly.>
Re: Tough Decision to Make
Do you think it would be prudent to treat him with Prazi Pro? I thought
that if its going to be tough getting food into him that I want to be
sure he's getting everything from what he does eat.
<If he's really hollow-bellied (concave around the abdomen) then sure,
pre-emptive anti-worming is unlikely to do any harm. Otherwise, if he's
basically normal-looking and actively feeding, I'd feed him generously
over the next week and see how he looks before doing anything else.
Re: Dolphin Fish, Mormyrid; hlth., sys., fdg f's
Hello again WWM Crew!
Thanks for your response, I really appreciate it! I am actually having a
dilemma with the dolphin, though I'm not sure if it's serious. As stated
before, I noticed less activity with these dolphins. What concerns me is
that now it seems like the larger dolphin is breathing differently when
sitting at the bottom on the tank. I asked before about the breathing rate
of this fish because it seemed like they naturally had a very fast rate.
<Yes; agreed. Some 90 gill movements per minute is not unusual in my
The worry I have now is that the dolphin is having trouble breathing. It
seems to be gasping so instead of a steady constant movement of the gills,
it stops then they flap a few times, then stops again.
<Not good. Water changes, activated carbon, PolyFilter or such I'd be adding
to the filter, water movement path>
The mouth also seems to be opening and closing with this, which I've never
seen it do. I also noticed besides the inactivity and breathing issue that
there looks like a few little bumps on the side of the larger dolphin. They
don't look like Ich or have any color, they look like they are part of the
<Still.... worrisome. S/b smooth>
I've continued to add more plants to the tank, but I'm unsure if the two
correlate. I have a 50g sponge filter as of right now, and was turning down
the intensity occasionally due to the air pump making a horribly loud hum;
but I don't know if this is the culprit as I have kept it going at full
strength since I noticed this problem and it seems to continue.
<You do have other filtration and water movement I hope/trust. I'd be adding
more... outside power filtration; hang on and/or canister>
I am heading into work today to replace it as well as getting a new
sandstone/airstone to see if that helps. I noticed some very mild flashing
about a week ago so after a w/c and plant trimming I added a low dose of
Seachem StressGuard and Seachem Stability since I cleaned the sponge filter
also. I rinsed the sponge filter with tank water to make sure I didn't
kill any bacteria, but when I turned the filter on a cloud of dust came out
of it. I waited 2 hours after cleaning the filter before I did my water
change/trimming and did not notice any stress from the fish. The only odd
thing I did notice that was different about this w/c was that the water had
an unusual amount of air bubbles in it making everything look foggy. I
discussed it with my fiancé and I suspect that the water may have been
cooler than the tank water, though he swore that it was warmer. The bubbles
made the tank look milky and the Otos were covered in bubbles afterwards.
Is it possible that the bumps came from the air bubbles? I'm unsure if the
products I used were a problem either seeing that both are extremely mild
and have been used before. The itching is only occasionally, but it's enough
to have me concerned.
<Me too... Act, now; re the above stmt.s>
They both still have moments of activity and do swim about chasing their
tankmates and they both have healthy appetites. I've got different foods as
stated before, but I've mostly been feeding live black worms. They seem to
be doing VERY well off of it and are both a healthy weight. Even the smaller
dolphin who looked frail and skinny, is starting to put on actual weight and
looks wonderful, though still tiny compared to the other. I keep the black
worms clean with a nightly cleaning before I feed them and don't seem to
have any losses with them. Even though I seem to have great results off of
blackworms, I'm aware that they can hold parasites
<Not really if they're cultured (vs. wild-collected). Ask your supplier re,
or wean them on to frozen/defrosted meaty foods (rinsed ahead of offering)>
so I'm wondering if there's a way to ensure my worms are parasite free i.e.
rinsing in Epsom salts or something; or is it safe to PraziPro these fish if
I did see any infection?
<I would not>
I'm looking into culturing my own live worms such as white worms as well,
hoping to try to reduce risk as much as possible.
Just did a quick strip test a moment ago
My temp is 79F Ph: 6.8-7.0Nitrate: .10ppm-20ppmNitrite: 0ppmKH: 40ppmGH:
Ammonia: 0ppm (did API vial test)
linking 2 videos from my photobucket of examples of the breathing, the
smaller dolphin flashing, and hopefully you can see the bumps though they
are near impossible to pick up on my phone. I saw some white specks on the
larger dolphin in the videos, but I believe they were from the sand since
they weren't consistently there even an hour before or an hour after. Black
spot still on the dorsal, and attached photo of the small bumps, forgive me
if they are hard to see, I could barely make them out in the photos but they
look like "chicken skin" like humans get. The white blobs in the photo are
baby apple snails. Excuse the messiness of my tank, they kick up the soil
onto the sand and I haven't planted the new plants, leaving algae for
and baby snails.
Thank you again for your time and I hope you'll be able to answer some of my
<Do please keep us informed. Bob Fenner>
Re: Dolphin Fish, Mormyrid 2/2/14
Hi WWM Crew and Mr. Fenner,
As of right now I only have the 50g sponge filter on this tank,
<Ahh! I definitely WOULD be upgrading, at least adding a good sized outside
power filter here. The improvement in water quality, reduction in
maintenance will be discernible>
I haven't been a huge fan of it's bulkiness but didn't realize it was a
problem since my water parameters have always tested well. I'm going to take
off one of my Eheim canister filters (80 gallon) from my 125gallon tank then
tonight. I'm going clean the entire filter with bleach then have it run
overnight in heavily dechlorinated water (prime) in a 5 gallon bucket as a
precautionary since I don't want to mix equipment between tanks.
<You are wise here>
I'll run both the sponge filter and the canister until I've got the canister
seeded enough. If the problem was indeed a filtration issue, I'll gladly
purchase a more suitable filter if necessary.
<Eheim's are excellent. I use them; have used them for decades, personally
I'm keeping my fingers crossed that this was the issue. In the meantime,
do you have any solutions to "disinfecting" my live blackworms?
<The continuous, long-term (hours) rinsing in slow, cold tapwater is about
all I would do>
I always grab my worms from fresh stock that just arrives and I clean them
nightly, but I doubt that it's enough to not be at risk still. I'm going to
speak directly to my wholesaler to see how they cultivate their stock, but
I'm weary knowing that PraziPro isn't an option if they have a bad batch.
I'll keep you posted, thanks again!
Have a wonderful evening, Lauren Saunders
<And you Lauren. Bob Fenner>
Re: Dolphin Fish, Mormyrid; hlth.
Hello Mr. Fenner and crew!
Giving you an update on the tank. After 15 minutes of running in bleach
water, 24 hours of running in heavily dechlorinated water, followed by a
thorough rinsing; I added the 80g Eheim canister filter to my tank. The
fish seemed fine with it for a few days, but now 2 Otocinclus just died
leaving me with one,
<The genus Otocinclus members are social... live in shoals>
though they stopped cleaning the algae and glass 2 weeks ago,
<? Something wrong here... low DO?>
unsure of the cause. Dolphin do seem more active though they always were
for the most part, but I still catch the larger resting on the bottom on
occasion, hard to tell with the smaller since it hides under the
driftwood when it's not searching for worms. The breathing rate doesn't
look as labored, but it is still an on and off motion (hard to explain)
rather than a constant flutter of the gills, though I did see similar
breathing patterns of dolphins via YouTube. Unsure which is the normal
pattern at this point. There are still weird discolorations on the skin
of the dolphin, unsure of the cause or if it's possible the Oto's were
sucking on their skin.
I noticed the Otos "attacking" when I had first gotten them, but haven't
seen it happening recently. Found it unusual since I thought this wasn't
a typical behavior of the Oto. Haven't witness any flashing from the
dolphin, but did see my blue gourami flash against the filter once last
night. Appetites are still healthy.
Water test: Nitrates: 10ppmNitrites: 0ppmPh: 6.8KH: 40ppmGH:
Will keep you updated if anything changes, but unsure if there's
anything I should be doing at this point. Doing my best not to mettle as
much as possible.
Have a wonderful day! Lauren
<And you. B>
My Elephant Nose Fish Won't Eat; rdg. 9/18/13
I have a 120L tropical tank with about 30 various friendly fish
<... Need to know; have you list, what these are... useful information
in determining compatibility and your system capacity>
I recently bought an elephant nose fish which started to eat, and
then unfortunately died.
<... Mormyrids are often lost in too crowded, too competitive settings...
have you read re the family on WWM?>
I then bought another one and have had him/her for about a week but
he/she hasn’t eaten anything and I'm quite worried as I don't want it to
<... too likely so>
I understand that buying another 2/3 may help,
<... don't do this>
but I don't want to waste the money and the life to try and make it
better. I always try and feed it bloodworms and other live foods but it
doesn't eat anything. I've just began to notice it sitting in the corner
of the tank looking as if it will die soon. Please help as I don't want
to risk any more fish.
and (all) the linked files above. This species, these species can be
"touchy"... but most all are lost due to inappropriate placement in
terms of environment, tankmates and feeding. Bob Fenner>
My elephant nose fish, feeding 8/6/12
Hiya I have a 4ft aquarium and i keep a variety of fish, danios, platy,
loaches, nothing big, but whenever i put bloodworms in for my elephant
fish the other fish are at the worms like their is no tomorrow.
<Yes; entirely predictable.>
I have tried doing what i can, i defrost the worms in a glass with some
tank water and put some in one end and some in the other end - (by the
elephant fish) but my question is - and i know you cannot give me an
accurate figure, but roughly how much should she be eating a day?
<Enough for her belly to be gently rounded outwards. If she's looking
thin, she's not getting enough to eat.>
a couple of worms, a whole cube? she seems to not know they are always
there and by the time the other fish have got their (she is very slow)
they have pretty much gone.
any fish you keep her in with no doubt will love bloodworms. so if you
could advise me how much she needs i would appreciate it.
Many Thanks, Charlotte
<Here's the deal: Don't keep Elephantnoses with bottom-feeding fish or
nocturnal fish. So no loaches, catfish, etc. Midwater schooling fish
like Danios are fine. Now, when you turn the lights out, both in the
tank and in the room, wait awhile for the daytime fish to settle down.
Then feed the Elephantnose in the dark! Chances are good she'll find and
eat all the worms. Of course you'll need more of a variety than
bloodworms; try frozen brine shrimp and frozen Glassworms as well. After
a few weeks of getting well fed like this, Elephantnoses usually become
physically stronger as well as bolder, and will feed during the day, and
I've seen them take baby brine shrimp in tanks during the daytime,
competing perfectly well with daytime midwater fish! But they have to be
well fed first, as described above, and not kept with catfish, loaches,
etc, so anything that falls to the bottom is left for them. Make sense?
nose feeding 1/28/08 Hello. Sorry I ask so many
questions. I just wanted to know, do elephant noses have to eat
live foods everyday? <Pretty much for the first few weeks.
After a month or so, once you have seen the Elephantnose eat and
know it is putting on weight and 100% sure nothing is competing
with it (such as a catfish or loach) you can also use (wet)
frozen foods such as bloodworms.> If not, how often? <Every
night.> Can they eat crickets or do they not know it is food?
<No chance.> Also, can they eat pelleted and flaked foods?
<No.> Last, how do you train them to eat pellets and flakes
and crickets? <Don't bother unless you want to starve the
fish to death. They will not take these food items. This is why
most people simply shouldn't keep these fish.> Thanks for
your time. <Cheers, Neale.>
nose continued... 1/28/08 Sorry, I forgot to ask... 1) what
is the approximate growth rate of an elephant nose fish
<Depends on the conditions, but should reach full size in
about 2-3 years.> 2) and can live foods be their main meal? Or
should it be a treat? <Live foods are the preferred food for
this species. Wet frozen foods such as bloodworms can also be
used once the fish is settled down and feeding.> 3) last, how
will I know if my elephant nose ate his food at night? I
don't want it to starve. he is the only nocturnal fish I
have) <If the Elephantnose is the only nocturnal fish, then if
the worms are gone by the morning, they've been eaten by him.
The fish should have a nice rounded abdomen. Do make 100% sure
the tank has a sandy substrate, not gravel, because these fish
feed in a very specific way by trawling the sand for food using
the chin barbel. Gravel can damage the barbel, and long term
seems to put them at risk of Finrot. Cheers,
Re: elephant nose... more re a child's
understanding, fdg. 1/28/08 Hi, isn't frozen food
everyday bad for the elephant nose? <No, it's fine for
them.> Aren't I supposed to mix it with flakes and
pellets? <Be nice if you could, but they won't eat those
things. End of story.> Or is frozen cube foods enough
nutrition for the elephant nose? <Yes; you do need to mix the
variety a bit, so you have bloodworms, white mosquito larvae,
Tubifex, etc. in the freezer. But your fish can live very well in
these things. Seriously, this is all my fish get, and they're
fine.> Also, do you know any good brands for frozen cube foods
that are cheap and has great nutrition and value? <They're
all much of a muchness in terms of cost. Here in the UK, a single
blister pack of frozen foods usually costs around Â£2.50,
though retailers often sell 5 for Â£10 to sweeten the deal.
There is a bit of variation in terms of flavour, it seems,
because sometimes the fish aren't as keen on a new pack as
they were with the old one. So maybe try out different brands and
types.> Thanks again Neale. Sorry for the inconvenience.
<Happy to help, Neale.>
Skinny elephant nose I hope you can help me, I bought a
elephant nose 3 wks ago. and he was doing fine, but lately he is not
eating. I feed him blood worms at night, so that my Angel fish
can't see it, but the cat fish go at it and my CAE, so leaves
nothing for the elephant fish. <Sounds like it is mixed in with
incompatible tankmates> I have tried many ways of trying to feed
him, I have placed it in the ghost tube, which he doesn't go in it
any ways, which I don't know how to coax him in there. I have tried
with a turkey baster and he would swim away, he has eaten a little bit,
but not enough he is starting to look skinny, I hope you can help me
before he dies. <I would move this fish to more suitable quarters.
Now. Bob Fenner> Thanks, Shelley
Longnose elephant fish Dear Mr. Fenner: I am inquiring about
the long nose elephant fish. <Mormyrids, Africans...
freshwater for the uninitiated browsers> I have several and they seem
to be doing well, except I am not sure if they are eating or not. I
have tried flake food and they didn't seem to like that at
all. <Nope. Won't sustain them at any length.> Then I
read that I should be feeding them live black worms. The problem is
when I put the worms in the tank, I can't get the fish attention,
and they don't seem to know that the worms are there. What am I
doing wrong? <Maybe the time frame... they're mainly
nocturnal feeders in the wild... and I would try other live foods as
well... Chironomid larvae (bloodworms), Brine Shrimp, Daphnia... or
small trials of these and other once-live foods that come
frozen/defrosted... at "lights off" time> Is there a
better way to feed these fish the black worms? Please help, as I really
enjoy these fish. Also I think I read somewhere that you can breed the
black worms yourself, if you have any information on this, I would
really appreciate it forwarded to me. <Yikes... will have to
resurrect some "pre-computer" writing efforts, or move up the
"to be written" "live foods/feeding" projects...
and quick. Do try the above suggestions for now...> I appreciate all
of your help and any and all information that you could provide me.
Thanking you in advance for your help. Sincerely, Shirley Schiavone
<You're welcome. I'll try to get to the live foods articles,
even the coverage of the family Mormyridae... but this will likely take
a couple of months... write in the meanwhile if you have specific
questions. Bob Fenner>
Dead elephant nose I bought an elephant nose
about a month ago and lost him 3 wks ago, after reading your
information on them, I wish I would have had the feeding test done,
then I would have known not to buy him, he would not eat and got
skinnier and skinnier, it was horrible, I brought him to the pet store,
and he wouldn't eat for them either, they treated him for internal
parasites for a wk in a half and he still didn't look good.
<Likely too far gone from the process of (likely chemical)
collection in the wild, starving, poor water quality from there through
shipping, handling... Happens to whole shipments at times> So from
what I read what you have wrote, do you have any ideas in what I could
do to keep my elephant nose alive, when I buy one in the near future.
Do you have any idea to why he wouldn't eat, because I did ask them
how long was he here before I bought him and they said 3 wks, and he
look good, apparently not or he would have ate. Also my water was good
where it should be, so I can't figure why he wouldn't eat?
<Morymyrids find aquatic worms almost irresistible... try
blackworms, Tubificids... if the specimen/s don't take these, I
would leave them at the shop> If you could help me it would be
appreciated, I don't know any where else to turn to there is not a
lot of people that know about these fish. <There is considerable
known about their esoteric biology, but not much popularized re their
practical husbandry... Many die from jumping out (for lack of an
adequate aquarium cover) and metal poisoning from errant medicine
treatment for instance... Easily avoided> Thanks, Sincerely Shelley