FAQs on Jack
Related Articles: Jack Dempseys, Oscars, Neotropical Cichlids, African Cichlids, Dwarf South American Cichlids, Cichlid Fishes in General,
Related FAQs: Jack
Dempseys 1, Jack Dempseys 2,
& FAQs on: Jack Dempseys
Identification, Jack Dempseys
Compatibility, Jack Dempseys
Selection, Jack Dempseys
Systems, Jack Dempseys Feeding,
Jack Dempseys Disease, Jack Dempseys Reproduction, &
Oscars 2, Neotropical Cichlids 1, Cichlids of the World, Cichlid Systems, Cichlid Identification, Cichlid Behavior, Cichlid Compatibility, Cichlid Selection, Cichlid Feeding, Cichlid Disease, Cichlid Reproduction,
Behavior Issue in EBJD 2/5/14
HI I am the proud owner of two electric blue jack Dempseys.
Currently they live together with an African clawed frog.
<Yikes... Xenopus eat fish>
They are juveniles maybe one and one half inches. They had some
guppies living in the tank for a while and as soon as they were removed
the fish seemed to withdraw. They are very skittish and
disappear whenever I approach. They each have their own
hiding spot and don't often come out. Although they do have an
excellent appetite and eat well. They and the frog ignore each
other and he is not big enough to bother the fish. Is the meaning
of this retreat something environmental that I can change?
<Just patience... they will learn to ignore your approaches; and even
appreciate you, connect you with foods/feeding in time>
Are they similar to shy saltwater species that need active social
tankmates to increase their confidence?
<Dither fish can help... but is there room here?>
If so what kind of fish might help to increase their confidence?
Their tank has 0 nitrites and ammonia, and nitrates fluctuate
slightly but average a bit high maybe 25-30 ppm if that is the
accurate form of measure.
I change about thirty percent of the water weekly. They seemed so
much happier with those silly guppies in the tank, what happened?
<Do read re the species on WWM... the search tool, indices... I'd keep
NO3 under 20ppm. The means to do so are also covered on WWM... Bob
Jack Dempsey Behavior 3/8/13
Hello I just got a 8-9 inch female (I think) jd and I put it in my 55
3 other jd size are about 4-5 inches and a 6 inch Texas cichlid. Well
beat up the Texas cichlid pretty bad but what I really wanted to know is
she has been lip locking with what I think was a male. Wasn't really
attention because I noticed her upper lip was tore open and that one of
fins was also tore up. So I took her out and put in own tank. Is this
normal mating behavior or fighting? Also wanted to know if her fins
ever grow back? Thanks eddy
< Male cichlids are usually larger than females and have longer fins. A
female usually has a lot of blue coloration along the lower jaw and not
much color in the body. Males are just the opposite. Lots on Google for
images and you should be able to see the difference. Typically males get
to 12 inches with females getting only 6-7 inches long. Lip locking and
flashing are all signs of cichlid mating behavior. Torn fins usually
back if they don't get fungused.-Chuck>
Jack Dempsey female – 05/13/12
I've noticed that my female JD was been chased by the male
(it was like a week ago when the chase begun) since yesterday she is
been in the bottom of the fish tank, sometimes getting in to different
caves with and without the male but now the male doesn't chase her . How
do you know if she has eggs in her belly?
<About one day before spawning the "genital papilla" should be visible
on the female. It looks like a short, off-white, rounded tube. The male
has a longer, narrower, pointed tube, and his is (usually) visible most
of the time.>
Can you tell me more about the JD female behaviour?
<Anything specific? Much like any other Central American cichlid. Rocio
octofasciata form stable pairs, both sexes looking after the eggs and
However, if the male doesn't want to female (for some reason) he will
drive her out of his territory, and will, if she can't escape, kill
By the way my fish tank is 150ish gallons and I have convict cichlid
with the JD
Rocio octofasciata.; behaviour 4/25/12
In my fish tank I have convicts and jack Dempseys I got my JD three days
ago I haven't seen any fight between them yet but I have noticed that my
JD haven't ate I feed them with Hikari cichlid pellets what you
recommend me to do?
<Wait. How big is the tank? I have to assume at least 75 gallons,
otherwise there will be merry hell in this aquarium once these fish
reach sexual maturity. Realistically, Jack Dempseys and Convicts can
cohabit in large aquaria, but as pairs, both species are best kept
Also the JD female is always following the male wherever he goes what
does this mean?
<They may well have paired up. That's a good thing, but of course once
they start breeding you'll [a] watch as your JDs kill off everything
else in the tank; and [b] end up with thousands of JD fry you might (and
probably won't) be able to give away, let alone sell. On the other hand,
if the two JDs are paired, at least they aren't killing one another,
which is what two sexually mature males would do in anything less than,
say, a million gallons (I exaggerate, but only slightly; they're named
after a boxer for a reason, and it ain't alliteration). Cheers, Neale.>
Electric Blue Jack Dempsey Growth
Hi, I just wanted to ask you a question. I recently got a new 30 gallon
tank for my birthday, (I'm only a sophomore in high school) an
while at my LFS, I noticed some beautiful Electric Blue Jack Dempseys.
The store owner told me that they don't get nearly as large as the
"normal" JD, and it would be fine to keep a single specimen
in a 30 gallon tank. I am not sure whether this is good information, or
if they're just trying to make a quick buck. They seem to know what
they're talking about and helped me with my 10 gallon tank (which I
have had running for a few years). I was hoping you could shed a little
light on the subject and give me some peace of mind before my
< The EB Jack Dempsey is a line bred Dempsey that is not as strong
as a normal Jack Dempsey. I know that they are slower growing but I
think they eventually get to be pretty close to a normal JD of about
8" fpr males and 4-6 inches for females. If they are breeding then
much of their energy and grow go into spawning and the growth slows way
Also, as a side question, if I ever get a larger tank, could I keep a
Firemouth with an EBJD?
< If you only have two cichlids in a tank, then one will always
bully the other one around until it is dead.-Chuck>
Jack Dempsey, beh. (growth)
I have a 7 inch Jack Dempsey (male?)
in a 70 gallon tank. I read online that some Jack Dempseys grow
up to 10 inches, but some stay smaller, at only 8 inches. When
will he be full grown?
<May be now...>
I am just curious if he still has a lot of growing to do yet.
Thanks so much! Lena
<Only time, good care (feeding, water changes...) will tell.
Cheers, Bob Fenner>
Re: Jack Dempsey 3/17/11
Thank you so much Bob! He is only about 10 months old, so he is
still a youngster.
<Wow! Big for his age>
I am hoping he will get to a good size, but I really do adore
this fish! I used to keep an Oscar, I really enjoyed him as well,
but after he passed on, I had a tough time deciding which species
I wanted to keep. I decided on A Jack, and haven't regretted
my decision once! thanks again, Lena
<I kept, bred this species when I was a youngster. A really
neat, intelligent fish. Cheers, BobF>
Re: Jack Dempsey 3/18/11
Yes, I think he is beautiful, much more so than an Oscar. I
always refer to him as my aquatic dog because he rushes out to
greet me every time I approach the tank. He doesn't seem to
like other people though, he even hides from my husband. Are they
usually this shy?
When we have guests they always think that we have an empty 70
gallon tank sitting in our living room.
Help with Jack Dempsey Cichlid!
Hiding Jack Dempsey 10/14/10
Hi there, I have a 5" Jack Dempsey alone in a 70 gallon tank. I
have had him for about three months now and he has been an extremely
happy camper the entire time. I do weekly 50% water changes including
vacuuming the gavel every time. I feed him cichlid pellets, and frozen
shrimp and blood worms (thawed of course). All was going so well until
late last week he started acting strangely. He hides a lot more often
in his flower pot, and rarely comes out to eat; when he is in his
flower pot he floats on his side right up against the top. He has also
become much more skittish, and flits around the tank in complete chaos
running into everything, but does this randomly, when nothing else is
happening in the room or when someone approaches the tank. I can keep
him calm when I approach if I approach very slowly and make sure there
are no vibrations in his water. He looks completely fine, normal colour
and no abrasions or marks on his body of any sort. Nothing has changed
in his schedule at all, except now he doesn't come out to eat as
often. What could be wrong? I really love my fish and would hate to
lose him! Thanks so much! Lena
< Your Jack Dempsey feels threatened in a big tank by himself. You
need to get some dither fish. These are usually large schooling fish
that are out in the open and provide some movement so your jack
doesn't get spooked every time something moves in the room. Good
candidates are large schooling fish like giant Danios, silver dollars,
Fish question, beh... 6/13/10
Hi Crew of Wet Web Media.
I have a question about my 6 1/2 inch Jack
All the tanks levels are good,
<Meaning what precisely? For Rocio octofasciata, you're aiming
for a middling temperature, 25 C is fine, and moderately hard, basic
water, around 15 degrees dH, pH 7.5. As with all cichlids, nitrite and
ammonia should both be zero, and nitrate as far below 20 mg/l as
and he's been in that tank for 2 years minimum. (He's 3 years
old. I got him when he was an inch or so and had no idea that he would
get that big, but once I found out I got him a 55 gallon tank, much to
my husbands chagrin.)
<Hmm... I'm surprised you were surprised. These fish are very
common, and any aquarium book should have told you they got big and are
very nasty in terms of behaviour.>
I had an 11 inch Pleco, but when the jack started acting weird, I
figured it might be stress from getting pushed around so I put the
Pleco in another tank. The Pleco really was a jerk, but the jack is
kind of a wuss. I also have 2 gold fish in the tank that started out as
feeder fish but never got eaten, again because my jack is a wuss.
<I'd say he was more "sensible" than anything.
Let's be crystal clear here: feeder fish are D-U-M-B. There's
no pluses to using them, and every time you use a feeder goldfish or
guppy, you're increasing the chances your supposedly precious pet
will get sick. Simple as that. Don't mean to be overly belligerent
or anything, but it eludes me why feeder fish are still so widely used
in the US when it is universally known they're a bad idea.
Anyway, I'm glad your JD was smart, and I hope you're enjoying
the Goldfish. For what it's worth, a 55 gallon tank is pretty
crowded with these four fish living in it.>
Anyway, a few weeks ago my jack started hiding way more than he usually
did. He used to swim around the tank all happy and joyful, but now he
hides all day long.
<JDs come from shady, forests streams if I recall correctly. They
aren't wild about either bright light or open spaces. So checking
the layout of the tank will be a plus. A few clumps of floating Indian
Fern can make all
the difference. Obviously they dig a lot, so plants won't otherwise
be an option.>
Sometimes his color changes and he looks super stressed. He started
flashing, so I treated the tank for ich, but it didn't help.
<Likely not Ick. Most of the time fish "flash" it's to
do with either rapid pH change or non-zero ammonia/nitrite
He eats, but not nearly as much as he used to.
<Oh. Now, with cichlids, appetite is usually an excellent indicator
of overall health.>
He used to come to the top of the tank and eat (flakes, cichlid food,
blood worms, brine shrimp, all kinds of good stuff along with feeder
fish maybe once a month or so),
<Arghhh!! Feeder fish! Please please please understand that feeding
a feeder fish to your pet is rather like me opening your mouth with a
crowbar and pouring down some biological waste from a pathology lab.
not kidding here. Once you start using feeder fish all bets are off. I
have no idea what parasites or bacteria you've introduced into this
aquarium. Plus, Goldfish contain fat and thiaminase that, in the long
term, cause major problems.>
but now he'll only eat if something floats right past him.
<Not good. Stop feeding for a few days, maybe 4-5 days. Then try
again with something super-delicious, like an earthworm or a small
piece of white fish fillet (not red or chicken meat). Don't use
dried foods, and if you can't
be sure about the quality of your wet-frozen or live foods, don't
use those either.>
I chalked all this up to stress even though I had a feeling it was
something worse. Last night though, it looked like he had a
<Again, sounds ominous. Firstly, check water quality and pH, as
mentioned above. Secondly, and I hate saying this, there are parasites
that can cause this sort of "Whirling" and they almost always
come into the tank via live
foods, especially Tubifex and feeder fish.>
All of his fins twitched super fast for about 3 seconds. He didn't
swim in circles or hit anything like a lot of the accounts I've
read on your page.
He just stood still and twitched. What is wrong with my Jack? I love
him and I'm afraid he's going to die if I don't figure this
<Check environment, diet. Tell me precisely what the temperature,
hardness and pH are, and confirm you have zero ammonia and nitrite
levels. Then hold off feeding as stated (you can let your Plec and
Goldfish nibble on some
cucumber, Elodea or Indian fern without worrying about them needing
I look forward to your reply.
<Hope this helps.>
Re: Fish question 6/13/10
First, thank you for the advice. I really appreciate it.
Your site was the only one I found with any useful information other
than the general knowledge of cichlids on other sites.
When I got the jack, I was hugely pregnant and lonely at home all day.
I got the jack because he was so lively. I never looked into how big he
got until afterward.
That was the first fish I ever had besides goldfish. Anyway, I had no
idea feeder fish were so bad for him until recently.
Everything I came across online and even with talking to the people in
the pet store.
<Well, US pet stores at least *sell* feeder fish, so they're
bound to tell you're they're safe and nutritious! As for online
sources, you have to be sensible.>
I know they're not the best people to ask, but I figured they had
to be right otherwise they wouldn't sell so many feeder fish.
I guess I figured thousands of fish owners can't be wrong.
<Oh but they are.>
I know that's dumb because that has never applied to anything in
life ever, and in fact the masses are usually terribly wrong.
<Often, yes. Humans are very, VERY bad at judging risk. As a parent,
I'm sure you'll appreciate the irony to people driving their
kids to schools so that their kids are safe from axe-wielding child
murderers, yet the risk of
exposing their children to fatal traffic accidents far, FAR outweigh
the likelihood of a child being murdered. The temptation to do the
right thing on gut instinct often doesn't make any sense at all
when you study the quandary scientifically.>
The logic seemed infallible to me at the time.
The fish seemed to love them so I thought I was doing good by him. The
water temperature is 80 degrees Fahrenheit.
<Too warm. 25 C/77 F is about the ideal for most tropical fish, and
more species prefer cooler conditions than warmer.>
The nitrates are as close to zero as possible (at least under 20mg/l)
and nitrite and ammonia levels are at zero.
I've been doing 30-50% water changes ever few days to make
And he is a precious pet. I wish I would have known a long time ago
that the feeder fish were so bad for him. I feel terrible actually.
<Trust me, I know all this stuff because I've been keeping fish
are very long time. Like many things in life, fishkeeping is very easy
once you've been doing it a few years, but initially at least it
can seem very complex and filled with contradictions.>
The only other variable that has changed in a long time is the fact
that the 2 gold fish spawned. None of the eggs survived because the
Pleco ate them all, but I did see the jack eating them too.
<Free fish food!>
I can't imagine this would make much of a difference since the fish
(and therefore the tank) had to be pretty healthy (I'm guessing)
for that to have happened.
Apparently I don't know what I'm talking about though, since I
thought the feeder fish were good in the first place. I'm going to
do what you said with not feeding him for a while. I hope it clears up,
but I'm not optimistic now that I know what I do.
<As I say, starve him a few days. Add some shade, or else switch the
lights off. Turn the heater down a notch.>
Why do petstores sell those damn things if they're so bad?!
<Same reason tobacconists sell cigarettes: profit.>
It makes me angry that finding out they were terrible took so long.
<Think how I feel! Every week having to tell people this stuff when
it's too late to do much good!>
This should be common knowledge, and from what you're telling me,
apparently it's not.
<In England and Europe generally, feeder fish simply aren't
used, and haven't been for 20 years. It's a peculiarly American
vice that honestly makes no sense to me. It's not like Europeans
are somehow better when it comes to animal cruelty or more
knowledgeable about parasitology. But for some reason, in the US the
idea goldfish make cheap and safe food items is just part of the
pet-keeping culture. If anyone can explain this to me, I'm all
These pet stores pride themselves in having only the "best"
for your pet, but I guess they don't include fish in their
description of 'pet'.
<Oh, I'm sure it's not actual malice; more a lack of thought
than anything else.>
I just hope he gets better.
<As do I. Assuming the water is good in terms of quality and pH, try
starving him, and see what happens. If after a few days he's still
off his food, then e-mail me back and we can try something else.
Metronidazole is often a good first medication to use with cichlids if
they aren't feeling well for nebulous reasons; if your pet store
has this, or Nitrofuranace, either would be worth using as
My jack is older than my 2 year old daughter, and not only do I love
him, but she does too.
She will gladly spend 20 minutes (which is long time for a 2 year old)
watching swim around, pointing to him saying 'big fishy! Happy
fishy!'/ She also calls the goldfish 'mommy fishy' and
'daddy fishy', but that's neither here nor there.
<Excellent. It's nice to see children learning to care for
animals through their parents. One of my pet peeves is people buying
animals for their children, and then complaining when the children
neglect those animals. But for their parents to be pet owners, and then
for kids to pick up the skills of empathy and responsibility via their
family pets, well, that's great.>
Again, I truly appreciate the advice.
<Glad to help. Cheers, Neale.>
Re: Fish question... FW... Pleco... Neotrop. cichlids, UK
and USA kids? 6/14/10
I think everything might be ok now!
Stress is a hell of a thing. Like I said, I took the Pleco out a couple
days ago. Since then, the jack's condition never changed but after
to talking to you I realized he probably didn't know the Pleco was
<May be so...>
So I changed 50% of the water and rearranged the tank, giving him the
opportunity to explore and determine new territory. Since I did that,
he's back to his old self!
I think he's now certain the Pleco won't be beating him up
<Or rather, he thinks he somewhere outside the Plec's
He's been happily swimming all over the tank for the past hour or
so. His color is back to normal, and in a few hours I think I'm
going to drop a few pellets in to see what happens. If he still
doesn't eat I'll let you know.
I really can't stress the fact that the Pleco was a jerk
<Well, "jerk" is perhaps too strong. Both sexes are
territorial, and among other habits will dig burrows that allow them to
survive dry spells almost like lungfish. The males also guard the eggs
and fry; they're astonishingly diligent parents. But the flip side
to good parenting skills in the animal kingdom is a certain degree of
I got him because I read they did well in community tanks, and he did
for a long time. I got him when I bought the bigger tank, so they lived
together for about 2 years. As he got bigger, he obviously got more
territorial but the jack held his own.
<Which meant that the Plec and the JD saw one another as rivals. Had
the JD ignored the Plec, there wouldn't have been any problem.
Plecs get on very well with non-burrowing cichlids such as Oscars and
Severums. But JDs
exploit similar caves to those favoured by Plecs, so in a relatively
small aquarium, there's bound to be competition.>
They seemed to have a love hate relationship. That Pleco was a smart
He used to swim to the top where the food pellets would gather and
he's manage to catch one and lick it to death. All of a sudden, I
guess the jack couldn't take the crap anymore.
<Plecs are well armed and well armoured, despite being mere
Cichlids are quick to learn. If the Plec did something, even
unintentionally, that hurt the JD, the JD might not forget it, and what
you saw was a persistent memory; the JD connected the Plec with
I also put a large plant in the tank. It's not real, but it's
tall enough that it blocks out some of the light. I usually don't
keep the light on very much anyway, but I'm sure it will help. I
don't put the light on during the day and when I do turn it on,
it's usually lit for about 2 hours and then I turn it off when I go
<That's fine. The JD couldn't care less if you never turned
the lights on.>
I was so worried about this guy. I hope his happiness lasts and he
isn't just teasing me.
<So do I.>
Thank you so much for your help and for letting me know how bad the
feeder fish really are. Never again will I feed him the feeder
It has to be so aggravating to hear the same thing over and over about
people fed their fish them, and all of a sudden they're sick.
I'm honestly surprised that the 2 I have now grew into the fish
They're really cute too. The 2 goldfish never leave each
They've always been a pair.
<Schooling fish. In fact Goldfish are lovely animals, and one reason
I get cross about their use as "feeders" is that they're
such excellent pets themselves, and just as smart as cichlids. Goldfish
are widely used in labs precisely because they're easy to
I think the allure of the feeder fish is part a sick obsession with
seeing an aggressive fish eat a tinier one (because Americans are sick
people in general),
<Quite possibly unfair!>
but I also think in part that it's because we want to mirror their
natural environment as much as possible.
<A false assumption. How many zoos operate this way? Or public
What works in the wild doesn't work in captivity.>
My line of thinking was, if he hunts in his natural environment and
that seems to be his instinct, I wanted to provide that environment as
much as possible for him. I wanted him to be able to exercise his
hunting skills, but he can do that with other things from now on.
<Quite so. JDs eat a wide variety of prey, and while small fish will
be an element of their diet, such prey are a very minor portion. Mostly
they're eating insect larvae and other small invertebrates. So try
earthworms, midge larvae, mealworms, even houseflies. In fact
there's no need to provide live foods at all -- your specimen comes
from stock bred in captivity for decades, and is no more
"wild" than the average pet dog.>
On a side note, my daughter is FANTASTIC with our pets! Every day
she's the one to tell me to feed our cat. I pour the food into the
bowl and she puts it down for the cat. I think it's instilling a
sense of responsibility.
About 2 weeks ago I set up a tiny tank for her with a snail in it and
she couldn't be more enthralled with it. She loves Gary (the snail)
from SpongeBob Square pants, so now our snail is named Gary.
I agree with you on the driving kids to school thing whole heartedly.
Not only is it far more dangerous, but it is teaching these kids to be
<A problem on both sides of the Atlantic, believe me.>
My daughter will be walking to the bus stop and standing there in 20
degree (F) weather just like I did.
<As did I. Builds character as well as strong calf muscles!>
It's not that I want her to suffer in the cold. I just don't
want her to think that just because something is unpleasant that she
should be able to get out of it.
<A crucial lesson. All too often it seems parents try to shield
their children from the unpleasant realities of life rather than trying
to provide them with the support and understanding that will allow
those children to learn about those realities. Much better I try
something and fail when I'm young, and learn how to recover thanks
to a caring parent, than wait until I'm off at university and alone
for the first time, and then suddenly find myself miserable and
When I see kids being driven to school when they should be walkers, it
makes me sick. That is why America is so fat.
<Agreed, but the British are really not very far behind,
No one takes the time to show their kids that walking places is a good
<Oh, some Americans certainly do, I have family in the US who are
just as good about walking or cycling or public transportation as I am.
But urban sprawl and the loss of sidewalks and real neighbourhoods has
made it difficult for many Americans to be a nation of walkers.>
People don't show their kids a lot of things due to laziness.
<It does scare me a little than American kids are assumed to become
drivers between 15 or 16, and from that point onwards expected to drive
to college, drive to work, drive to the shops. The irony of driving two
miles to the gym so you can do an hour on a treadmill is lost on far
too many people! I was discussing the BP oil spill a few days ago, and
one of the points I made -- I should mention here I'm a BSc
zoologist and PhD geologist -- is that the oil spill isn't that big
of a deal in the long term. The important thing isn't the dead
seabirds, though those are surely bad things, but that if you want to
rely on oil, then someone has to dig the stuff up, and drilling is
dangerous, technically difficult, and periodically accidents *will*
happen. If you want oil spills to happen less often, you should use
less oil, and part of that is driving less.>
Sometimes it blows my mind. It takes next to no effort to teach a
toddler something, and still people can't do it.
<Lots of toddlers seem way smarter than their parents!>
My daughter just turned 2 in April, and she can already count to 10
(and recognize the numbers out of context), she knows all of her shapes
(including oval. For some reason I'm very impressed that she knows
that), all of her colors, the difference between right and left, among
other things. We're learning letters now.
<Very good! I know I was taught these sorts of things long before
going to school. But somewhere along the line we confused
"education" with "going to school". They aren't
the same thing. Education is something you do yourself or within your
family for your entire life. You should be educating yourself to the
day you die. I've known some fantastically educated people who
never went to college. They read, they talked, and they experienced
things. At the same time, I've known people with PhDs who are
dumber than a box of rocks.>
Slowly my country's education is going down the drain, and people
<Again, I think all "rich" countries experience this sort
of thing, as the value of education seems less and less compared to,
say, celebrity or sporting skills. Here in England surveys suggest that
something like 75% of teenage girls want to be either celebrities,
sportsman's wives, or glamour (i.e., topless/nude) models; fewer
than 10% want to be professionals of any sort. It's as if feminism
never happened. I hasten to add I have nothing against women who sing
pop songs, marry footballers, or take their clothes off; indeed, like
most men, I can find that sort of thing rather appealing!
But the staggering lack of intellectual ambition is worrying, and makes
you wonder what sort of signals they're getting from both male and
female role models in their families and from the media.>
We have a country full of people who sit on the couch all day and get
all of their education from TV. If I could raise my daughter in Europe
without taking her away from her family, we'd leave in a
<Oh, that's a bit unfair. I lived in America for three years and
regularly visit for family occasions. I love the place! "The grass
is always greener..." they say, and I think both Europeans and
Americans often have one-sided views of the countries across the
Atlantic. Both have their pluses and both have their minuses. Americans
often get the simple things wonderfully right -- iced water at
restaurants, wonderful national parks, and an openness and friendliness
to strangers that really is unique.
Europeans get other things right -- much better bread, useful public
transportation, mistrust of flag-waving overly-patriotic politicians.
Of course, Americans and Europeans both agree on one thing -- we'd
move to Canada in a heartbeat if it wasn't so darn cold!>
Ha. Sorry about the rant. I'm kind of bitter.
<Ranting fine, bitterness not usually helpful.>
I've seen how Europe works first hand and I envy it.
<As I say, sometimes it works, but sometimes the American way is
The majority of the countries over there provide more freedom to their
citizens than America does, even though we're known for being the
'land of the free'. It doesn't make sense.
<Again, I think there's pros and cons to both. Europeans are apt
to feel smug because we don't execute people and we do have a court
of human rights, but we learned those ideals from the United States
(though the Founding Fathers did of course get those ideas from
Englishmen!). If America has a challenge right now, I think it's
for the people to go back to the Declaration of Independence, the Bill
of Rights, and the Constitution, and look again at what the Founding
Fathers were trying to achieve. It didn't involve detention camps,
torture, invading foreign countries, or mixing religion with politics.
The irony is that the goals the Founding Fathers advocated are
precisely the ones the rest of the world idealises about the US, and
should be easily spread to nations around the world. That's what
the religious fundamentalists around the world are most scared of, not
tanks, fighter jets or cruise missiles. But we're way off topic
Again, thank you so much for your help, and if his condition worsens
you'll be the first to know. It's good to know there's
someone reliable to ask these things about on the internet among the
<Always glad to help.>
Electric Blue Jack Dempsey acting strange
First off, I greatly appreciate your work and visit your site often for
your helpful information as I am a beginner when it comes to the fish
<Kind of you to say so.>
This is the first time I am writing with a question of my own.
I have a year old electric blue jack Dempsey (about 4 inches) and is
not his usual self. I woke up today and he was moving up near the
top of the tank by the heater.
<With cichlids, this is a common reaction when living conditions
aren't as they should be. Cichlids are peculiarly sensitive to
things like low water temperature and poor oxygenation. High nitrate
levels and pH changes can cause similar effects.>
Usually he swims all around and is very active. For most of his life he
was living in a 10 gallon tank (which I know I kept him in for too long
but had problems setting up my 36 and did not want to put him in there
until the tank was ready and properly cycled) and recently was moved
into a 36 gallon community tank.
<Jack Dempseys are hardly community fish...>
He is in there with a couple tetras and a red tail shark which he gets
along fine with.
About 4 months ago, my heater in his 10 gallon malfunctioned and
brought the temperature up to 98 degrees overnight.
I was very upset because the heater practically cooked him, but luckily
he is a fighter. After that happened, he had a slight case of fin rot
but I treated that quickly with Melafix. Ever since the heater
malfunctioned, it seems as if his eye sight has deteriorated.
He is just bad at catching food when it is falling through the water
but can still pick it up off the sand.
<So long as he's able to eat something, and has at least one
good eye, I wouldn't worry unduly.>
Just a week ago I changed the filter pad in the 36 gallon tank. The
temperature is 79 degrees, ammonia and nitrites 0, nitrates 10, but my
Ph is in the high 7's. This high Ph is normal in my tanks due to
the water quality where I live, so my fish are used to the slightly
higher Ph levels.
<Not likely an issue here, since JDs need hard, basic water. You
should be aiming for about pH 7.5, 10-20 degrees dH.>
I have sufficient filtration and aeration in the tank.
<Ah, but do you... Do check water quality; cichlids are among the
first fish to react negatively to non-zero nitrite/ammonia levels, and
they also despise nitrate levels above 20 mg/l.>
Yesterday he was completely normal when I checked on him before work
around 4pm. Then around 8pm my mother started noticing him acting
strange. He is not bloated, he is eating fine, and his poop looks
normal. If I seem too concerned, forgive me. He is my buddy and I just
want to hear your thoughts. If you think he has a specific problem, I
just want to know as soon as possible to start treatment or
<Difficult to say what's the issue here. Start with possible
social behaviour factors. Is he being bullied or nipped? You have at
least one Shark Minnow (known to be aggressive) and some tetras (some
of which, like Serpae and Black Widow tetras are confirmed
fin-nippers). Check water quality. Check water circulation, and if you
can, do a water change today. Change out 25%, and if the fish peps up,
that's a clue water conditions are at fault. Do read up on Central
Thank you for your time,
Rick and "Jack"
Re: Electric Blue Jack Dempsey acting strange
Thank you for your advice and I caught the culprit in the act.
Problem was my red tail shark.
<Am I good or what!>
My electric blue is not an aggressive fish and was being bullied and
chased by the shark when I cam home from work today.
<Tables may turn once the Jack Dempsey gets larger.>
Shark is now out of the tank and placed in 10 gallon "prison"
for the time being so I can figure out what to do with him because I do
<Red-tail Sharks need large tanks; certainly the tank should measure
at least 120 cm (about 4 feet) from left to right. They have
considerable territorial instincts, and will defend that patch of land
against all comers. They aren't really community fish, unless kept
with small, schooling minnows and tetras that they generally ignore. In
cichlid tanks they tend to cause problems.>
My Jack is now swimming around like normal with the tetras, he is not
flashing anymore and all is well. Thank you again for your help and for
taking the time to help others like me with their finned friends.
<Always happy to help.>
Rick and Jack
Unusual behavior of Dempsey Parents -- 12/09/09
Hello! I love your website, it's very informative and I have
answered many of my own questions regarding my Dempsey's.
I have come upon a problem that I have not been able to find an answer
to however. I have a newly breeding pair of Dempsey's, in a 55
gallon that are about a year and a half old. They have spawned once
before, but none of the eggs were viable. Recently, however, they
spawned again and though they laid around 300 eggs, very few of them
hatched (maybe 60).
<Sixty is more than enough...>
The parents were very attentive as they should be while caring for the
eggs, until they hatched. Both seemed to lose interest, were not
displaying the classic "rounding up" of fry and within two
days of them hatching, the fry were attempting (more like drifting) to
<Inbreeding tends to dull the behaviours of cichlids over the
This is one reason advanced aquarists often go for wild caught fish
rather than farmed specimens. In the case of things like Electric Blue
Jack Dempseys especially, there's a lot of inbreeding going on
there, since people are cranking these fish out to meet the (temporary)
demand while the prices are still high.>
And then they vanished. Not only did the unfertilized eggs disappear,
but all traces of any fry. After doing so much research and keeping
Dempsey's for the past decade (this was my first pair, and breeding
experience) I was highly anticipating going through the experience of
watching the parents behavior and parental skills in action as well as
the maturing of at least some fry.
<If you've read 'King Solomon's Ring' by Konrad
Lorenz, then you'll know how influential this species of cichlid
has been in the science of animal behaviour, but cichlids have their
behaviours for a reason, to ensure successful reproduction. Bad parents
can't produce offspring, so their genes die out. On fish farms,
breeders pull the eggs out and rear them manually, so it makes do
difference whether the parents are clever or stupid. Both good and bad
genes get passed on, and over time, the best behaviours are washed
How disappointing this has turned out. Both parents are in tip top
shape, are non violent towards each other, and generally a great
<Again, a good clue not all is right with them. Rocio octofasciata
gained its common name, Jack Dempsey, after a boxer. The belligerence
that characterises the species is of prime importance to them in terms
of securing their nest and protecting their fry. If they've lost
the genes for aggression, perhaps they've lost the genes for other
Is there a reason that they have suddenly abandoned their parental
duties, and eaten their young? Everything I've read and heard about
them boasts about their excellent parenting, and nothing about
situations like this.
<Unfortunately for casual aquarists, books on aquarium fish are
written by advanced aquarists who seek out good quality fish. So the
photos of Mbuna always look brilliantly colourful, and their Guppies
are always hardy, and their cichlids are always great parents. But
these quality fish aren't the ones you'll see sold cheaply in
Petco type stores, where price, not quality, is the factor. If you want
to see the very best behaviours from a cichlid, you need to track down
wild-caught specimens, or at least the immediate descendants of
wild-caught fish. These may well be pricey, and they may also be
species you don't think are particularly attractive. But in terms
of behaviour, there's no competition. And actually, if you choose
carefully, wild-caught species can be extremely colourful, just not in
the same gaudy way as a Goldfish! Indeed, wild-caught Mbuna are
invariably much prettier than the farmed hybrid junk thrown into most
tanks. I don't know what part of the world you're in, but here
in England, the larger Maidenhead Aquatics stores as well as
independents like Wildwoods routinely get in wild-caught cichlids,
often varying across the seasons.>
Am I doing something wrong or do they simply need a few more times for
their instincts to "kick in"?
<There really isn't much you can do. With some species, notably
Angelfish, tank-bred fish simply cannot rear their fry at all, and you
can let them practice as often as you want and they'll never get it
right. We've bred them to be cheap and colourful, but also to be
dumb as posts. Sometimes cichlids eventually get it right, and
sometimes adding a fast-moving, semi-aggressive "target fish"
like an adult Gyrinocheilus aymonieri can strengthen the pair bond, but
I wouldn't bank on it (and you could easily end up with a useless
target fish you can't do anything with).>
I'd really appreciate any advice or answers that you may have.
Thanks in Advance!
<Sadly this issue has been reported again and again with cichlids,
with relatively few species immune. Oddly, Kribs seem to be very good
parents, even after generations of being bred on farms, though if you
can secure wild-caught Kribs, or better yet, one of the related species
like Pelvicachromis taeniatus, so much the better. There are some
pictures of my (wild-caught) Pelvicachromis taeniatus rearing their fry
Pelvicachromis are fairly peaceful, quite small (a 20 gallon tank is
ample), and can be kept with surface-swimming tetras without problems.
The are unusual in that the female prompts the male to spawn, and he is
only allowed back into the cave a few days after the fry have hatched,
so broodcare is somewhat asymmetrical. In the wild the males probably
have multiple females, but in captivity they do fine as pairs.>
<Hope this explains the situation a bit for you. Cheers,
Nervous Jack Dempsey Hi my name is Anette and I have a
question for you regarding my jack Dempsey. Lately his behavior has
been unusual. He tends to twitch, like a jerk back and forth and then
scratches against the rocks. Now I have checked to see if he has a
parasite or any changes in his color. He looks the same. He eats and
doesn't seem to isolate himself from the other fish. He seems fine
on the outside. Now he doesn't do this on a constant basis, but
when he does it is very strange. I don't know what to do or how to
detect what is wrong with him. If you can help me that would be great.
Thanks Anette < Check the nitrates. If they are over 25 ppm then
they need to come down with a water change. When the nitrates are
elevated the bacteria that are harmful to fish begin to multiply and
start to overwhelm the fishes natural defenses. I would do a 30% water
change, vacuum the gravel and clean the filter. Wait a few days and
watch and see if he gets better.-Chuck>
Question about cichlid behavior Hi! I have a Jack Dempsey (If
that's the correct name for it) he's about 3 years old,
approximately 8 inches long and right now he is living alone in a 55
gallon tank. I originally got him, a female Jack Dempsey and a 29
gallon tank all from a friend last July. The female died in only 2 days
but the male survived without any noticeable problems. About 6 months
ago I transferred him to the big 55 gal instead. At first he seemed to
enjoy it but for the last 2 months or so he hasn't moved at all
during the time I'm awake (usually about 10am-2am), he just hides
behind a big ornament. And whenever someone walks by the tank he
totally freaks out and starts shooting all over the place, if the hood
wasn't there he would've flown out of the thing at least a
dozen times by now. I've done small water changes and big water
changes, all the levels are fine and there's plenty of filtration,
air etc... I've been doing my best at giving him light cycles too
but it seems to me that he really dislikes the lights. I saw another
question you answered about trying to cover the tank for a few days
with a blanket and maybe I should try that but is there anything else I
can do as well? Maybe adding a couple other fish? <Hopefully this
will improve his behavior... maybe something fast like a couple of
Tinfoil Barbs...> I feel really guilty about wanting to get rid of
him but the reason I have an aquarium is so I can look at fish not
water! This is stressing me out! Any help will be greatly appreciated,
thank you so much! Todd <Thank you for writing. Bob
Jack Dempsey acting weird I have a 7" male jack Dempsey
and about a month ago he stopped digging and uprooting plants and he
isn't as aggressive as he used to be. he is in a 60 gallon tank but
he sits on the bottom behind a flower until I feed him. I am wondering
why he isn't acting like a regular jack Dempsey. thanks < Do a
30% water change and clean the filter. Raise the water temp. to 80
degrees F and add some live food like washed earthworms to his diet.
Add some driftwood or rocks to break up his routine. These should get
him moving around a little bit more. Watch him for signs of any
illness. Cichlids are actually fairly social creatures and benefit from
a change of pace to keep them interested.-Chuck>
Jack Dempsey Coloration 6.7.05 Hey Crew, I have been
noticing, over the past couple of days that my Jack Dempsey, Whiskey,
has been a little bit lethargic. Also his color has changed
to a kind of pale-ish gray like color, when before he was a very dark
black. I also noticed that two of his tank mates (Jewels)
have been hovering near the top of the tank together and not moving
much. Now they are not gasping for air at the surface or
anything like that, just kind of not moving in the top portion of the
tank, where as the Jack just hovers mid tank and stays
pale. I had treated all these fish about two weeks ago in a
QT for parasites, I think it was gill flukes. However I was wondering
what you all thought of this color and behavior change in the jack and
the behavior in the Jewels? All the other fish seem fine (a little
Firemouth, a synspilum, and a few danios) Thanks you guys are great
Dylan ps. I have them all in a 55 gal and all the water levels are
maintained <In my experience fish that hang out near the top corners
of a tank are usually being harassed by someone bigger and meaner
(I'd bet on the Jack), or are stressed in some other
way. The move to QT, medication, and back to the original
tank could have caused a lot of stress on all the
fish. Reintroducing everyone back into the tank may have
caused them to reestablish their hierarchy, so the Jack beat on the
jewels who are now hiding up in the corner, and the Jack is still
stressed from the QT and the move, not feeling so hot and not
displaying his best colors. That is just my
guess. I would ensure water quality is pristine, keep up on
water changes and watch for changes. The Jack should return
to normal. You might also consider adding some hiding places
for the jewels. Other than that I might try a different
brand of color enhancing food to see if it makes a
difference. Best Regards, Gage>
Red Color on Jack Dempsey's 7/4/05 I have 2 Jack
Dempsey's a female and a male I didn't know that the female was
a Jack Dempsey until recently. My question is, both of them are
starting to get red on their heads is this ok? < I am not aware of
any color variation of Jack Dempseys with red coloration on the head. I
suspect that it may be a bacterial infection and needs to be treated.
Do a 30% water change, vacuum the gravel and clean the filter. Treat
with an antibiotic like Furanace as per the directions on the
Jack Dempsey Cichlid Changing Colors I have a 55
gallon tank with three Dempsey's in it. Two are male and one is
female. I am wondering why they change colors, the female and one of
the male fish changes their color a lot but the other male Dempsey dos
not change color and am wondering about that too. Thank you, Chris <
Your larger male Jack Dempsey probably is the dominant fish in the tank
and pronounces his dominance with his usual coloration. The others may
still be sorting things out between themselves and the dominant male
and communicating their status with both their color and their
Electric blue Jacks... Chuck!
8/8/06 Dear crew, Best website in the world for a fish
enthusiast! Thanks for all your help in the
past. I recently (7 months) bought a pair of electric blue
jack Dempseys. <These are gorgeous> I've owned a tank or two
for years and thought I did all the right things, cycled the 85g for
about a month with some tetras, checked the water quality
constantly, etc.. When I purchased the fish they were about
an inch long. I put them in a 15g quarantine tank and gave
them Coppersafe, <Mmm, why?> salt and tetracycline gradually for
a few weeks. I moved them to the 85 and all was
great. After about 3 months I noticed that they weren't
growing. <This "sport" mutation does seem to grow
slowly... and maybe the copper and antibiotic exposure had an influence
here as well> One had a slight bubble over one eye but the behavior
was normal. About 2 months later, the other one just
died. No visible signs of disease or
injury. I'm now at the 7 month mark and I have an eb
Dempsey that measures in at an inch and a quarter??? <Man, tiny!>
I've had other south American cichlids in the past and
have been astonished at the rate of growth. I currently have
the fish in the 15g and had some leftover tetracycline I treated for a
week. I also use CopperSafe when I can with the other
meds I know that eb Dempseys are inbred, could it just be
genetic? <Yes... to some extent... but I don't think this is the
whole answer here> Should I treat for worms or something
I've missed? <... I would try not treating with some new
individuals... just the quarantine period. Am going to place this query
in our resident Cichlid expert Chuck Rambo's in-box (he's out
right now), and ask his input as well here> Please help, I've
been dreaming of keeping this fish for years. Thanks again,
Sacramento fish hobbyist <Oh! And have been up to the
Ca. State capital many times... the water is very good right out of the
tap for neotropical cichlids... Bob Fenner>
Scratching Jack Dempseys - 11/13/06 Hi, and thank you
for all of the help you guys give. I have 2 electric blue jack Dempseys
in a 60 gallon tank. They are about 2 inches each. One of
them has been seen flashing against various things in the tank. I have
had them now for about two weeks, no sign of ich, and they are both
eating bloodworms fine. I'm attempting to get them to eat pellets
by introducing them with the bloodworms as one of you suggested because
they have been refusing anything else. I've been doing
partial water changes due to some higher nitrates lately to keep that
down. They are active when I approach the tank and sit still
most of the time behind plants or rocks when left alone. Should I be
concerned about the flashing or is this some stress related to water
changes or being in a new tank? Thanks. < The high nitrates are
triggering the outbreak of bacteria that are attacking your cichlids. I
would recommend a 50% water change, vacuum the gravel and clean the
filter and see if things get better. Feed only enough food once a day
so that all of it is gone in two minutes.-Chuck>
Dempsey's are "playing" dead 2/3/07 We
have two Jack Dempseys. They are both about 4
inches. We had them in a 29 gallon in the entrance way of my
house and they always would hide. <Mmm, would be more
"outgoing" if placed in a setting where folks were about more
often> I have done some research that this is common behavior for
Jack's. Well we recently came across a 55+ gallon plexi
glass custom aquarium (for twenty bucks!! Yay!) We moved our
29 gallon and cleaned it seemed to really stress them
out. After we had our tank set up for a few days, we decided
to move them into the big tank thinking they were sad about the small
tank. (we also put a redtail barb and a Pacu in the tank and they are
thriving) <The Pacu will be too much alone for this volume in
time...> They stayed at the bottom in the plants like usual but two
days after the move I found my jack (the submissive) in the bottom
corner nose down between the pump and a plant. I thought he
was dead, but I couldn't get him out because the tank is about 5
feet tall. <?> So I was waiting for him to float
up. The temp had raised in the tank to 81 so we unplugged
the heater and light and chocked up the death to the water
temp. Well that night I went to check to see if he was
floating and he was swimming around the bottom with the dominant like
usual. When he spotted me peering at him both jacks got
skittish and freaked out. Tina as I call the submissive went
back to the corner nose down. Ike the Dominant one yesterday
was laying above the powerhead playing dead when my husband thought he
was dead and got the net he swam to the bottom. The two fish do swim
and play with each other when no one is looking. Why are my
fish being so WEIRD!!! Is this normal? Should I
put them back in the smaller tank like they are used to? Thanks I love
your Forum. Laurel Bent <Please send along the actual dimensions of
this tank... If it is such a strange shape, it may be that simple lack
of oxygen is a problem here... But very likely the system is just not
cycled... Read here: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm and
the linked files above. Bob Fenner>
Female Jack Dempsey turned black. Breeding Jack
Dempsey's 2/16/07 Hello, I have found a lot
of helpful information on your website. However, I still have a
question. I bought my 2 Jack Dempsey's a few weeks ago. I was told
the smaller one, who is a female, was pregnant. So, I waited for the
fry to arrive. < They are not livebearers. They will lay eggs first
and then the fry will hatch in a few days.> In the meantime, she
turned from a beautiful yellowish-gray fish with almost
glow-in-the-dark-like shiny flecks to completely black and nearly all
of the shiny flecks gone. < This is their breeding coloration. She
may indeed be ready to breed.> She is about 3 inches long, while her
mate is about 7-8 inches long. She has also become extremely aggressive
and has even killed Cheech, my convict cichlid. (I also have 4 Oscars,
1 red devil and 2 barbs in the 55 gallon tank.) They all get along and
she did too, at first. Can you tell me why she is black now and more
aggressive? < They are getting ready to breed. At least the female
is. She has begun to defend a territory and started killing the other
fish that are in the tank.> Also, we were thinking of moving to a
bigger tank. Is this the best option for all these fish, especially
since they are all over 5-6 inches long, except for the female JD? Any
help would be greatly appreciated. Thank you, Deanna <
All the other fish are in danger of being killed by the breeding pair
of Jack Dempsey's. Remove the pair or remove the other fish. A
bigger tank may help but for only a short while.-Chuck>