Electric Blues lose appetite for Neon tetras

[Jim Morcombe]

Can anyone explain this behaviour?

My comunity tank has loads of guppies, half a dozen angels, three Silver
Sharks, and a lot of bristlenose.

It also had seven Neon Tetras who usually stayed in one particular place in
the tank.

I bought my g/f seven juvenile Electric Blues and dumped them in the
aquarium until Christmas.

After the first night, had six tetras and they had changed their location
in the tank.

Each night the number of Tetras was whittled down until there were two left.

However, these two are still there and have survived for a week.

I don't seem to be losing guppies either, but this is difficult to verify.

Why are the Electric blues leaving the remaining Tetras alone?

Jim

[T]

"Jim Morcombe" > wrote in message
...
> Can anyone explain this behaviour?
>
> My comunity tank has loads of guppies, half a dozen angels, three Silver
> Sharks, and a lot of bristlenose.
>
> It also had seven Neon Tetras who usually stayed in one particular place
in
> the tank.
>
> I bought my g/f seven juvenile Electric Blues and dumped them in the
> aquarium until Christmas.
>
> After the first night, had six tetras and they had changed their location
> in the tank.
>
> Each night the number of Tetras was whittled down until there were two
left.
>
> However, these two are still there and have survived for a week.
>
> I don't seem to be losing guppies either, but this is difficult to verify.
>
> Why are the Electric blues leaving the remaining Tetras alone?
>
> Jim
>
>
>
>
>

Perhaps they need another flavour?? Try cardinal's.. j/k...

Tim...

[Rick]

"Jim Morcombe" > wrote in message
...
> Can anyone explain this behaviour?
>
> My comunity tank has loads of guppies, half a dozen angels, three Silver
> Sharks, and a lot of bristlenose.
>
> It also had seven Neon Tetras who usually stayed in one particular place
in
> the tank.
>
> I bought my g/f seven juvenile Electric Blues and dumped them in the
> aquarium until Christmas.
>
> After the first night, had six tetras and they had changed their location
> in the tank.
>
> Each night the number of Tetras was whittled down until there were two
left.
>
> However, these two are still there and have survived for a week.
>
> I don't seem to be losing guppies either, but this is difficult to verify.
>
> Why are the Electric blues leaving the remaining Tetras alone?
>
> Jim
>
>
>
>
oh they will get around to them in good time .

Rick

[Mephistopheles]

"Jim Morcombe" > wrote in
:

> Can anyone explain this behaviour?
>
> My comunity tank has loads of guppies, half a dozen angels,
> three Silver Sharks, and a lot of bristlenose.
>
> It also had seven Neon Tetras who usually stayed in one
> particular place in the tank.
>
> I bought my g/f seven juvenile Electric Blues and dumped them in
> the aquarium until Christmas.
>
> After the first night, had six tetras and they had changed
> their location in the tank.
>
> Each night the number of Tetras was whittled down until there
> were two left.
>
> However, these two are still there and have survived for a week.
>
> I don't seem to be losing guppies either, but this is difficult
> to verify.
>
> Why are the Electric blues leaving the remaining Tetras alone?
>
> Jim
>

Very interesting. I had a similar experience. I put 10 serpae
tetras in my South American cichlid tank, guessing that my fish
would leave them alone. Unfortunately, some fish (either my
Geophagus surinamensis or my Satanoperca) was preying on them.
Every few days their number would dwindle by one. Eventually,
there was only one left. But that one serpae has now survived in
that tank for six months! I think it has something to do with
schooling behavior. My current guess is that schooling fish become
much more cautious once a school no longer exists and/or predator
fish are less likely to go after them once there is no school.

Meph

P.S.: I assume you know that the water requirements of electric
blues and neon tetras could not be more different.

[NetMax]

"Jim Morcombe" > wrote in message
...
> Can anyone explain this behaviour?
>
> My comunity tank has loads of guppies, half a dozen angels, three
Silver
> Sharks, and a lot of bristlenose.
>
> It also had seven Neon Tetras who usually stayed in one particular
place in
> the tank.
>
> I bought my g/f seven juvenile Electric Blues and dumped them in the
> aquarium until Christmas.
>
> After the first night, had six tetras and they had changed their
location
> in the tank.
>
> Each night the number of Tetras was whittled down until there were two
left.
>
> However, these two are still there and have survived for a week.
>
> I don't seem to be losing guppies either, but this is difficult to
verify.
>
> Why are the Electric blues leaving the remaining Tetras alone?
>
> Jim

As the surviving prey become more adept at alluding the predators, the
benefit/effort ratio becomes smaller (basically they are becoming too
much effort to catch for the value of the meal). Sometimes the prey does
slip up, and gets to close to the predator's lunging range, so it's over.
Often the prey grows large enough to discourage the predator (ie: the one
feeder the Oscar never ate). Eventually the predators may forget the
meal potential and become complacent about the 'hunt'.

As your Electrics will vastly outgrow the adult size of a Neon, I don't
think size will save those little guys. Your Electrics might be
distracted by the need to hold the pecking order in place, and are
currently satisfied with the amount of food they get from you. It might
last, it might not.

Drop something like a Nimbochromis livingstoni in there. These guys are
highly food motivated (like the African version of an Oscar in this
regard). I don't think they could ever forget about food ;~)

NetMax

[Mephistopheles]

"NetMax" > wrote in
:

>
> "Jim Morcombe" > wrote in message
> ...
>> Can anyone explain this behaviour?
>>
>> My comunity tank has loads of guppies, half a dozen angels,
>> three Silver Sharks, and a lot of bristlenose.
>>
>> It also had seven Neon Tetras who usually stayed in one
>> particular place in the tank.
>>
>> I bought my g/f seven juvenile Electric Blues and dumped them
>> in the aquarium until Christmas.
>>
>> After the first night, had six tetras and they had changed
>> their location in the tank.
>>
>> Each night the number of Tetras was whittled down until there
>> were two left.
>>
>> However, these two are still there and have survived for a
>> week.
>>
>> I don't seem to be losing guppies either, but this is difficult
>> to verify.
>>
>> Why are the Electric blues leaving the remaining Tetras alone?
>>
>> Jim
>
> As the surviving prey become more adept at alluding the
> predators, the benefit/effort ratio becomes smaller (basically
> they are becoming too much effort to catch for the value of the
> meal).

Hello net max,

You make some interesting points, as always. By the way, I asked a
couple of biology professors about this behavior and neither one
could really come up with a definitive answer. I think you may be
onto something, but I am skeptical that it is the complete
explanation. First, with regard to fish such as neon tetras and
serpae tetras (the latter were the fish in my example), I am
skeptical that they really become "more adept" at eluding predators
-- I think they are just too stupid. Instead, they are pretty much
always relying upon a hardwired instinctual toolkit when evading
predators. Moreover, if it were just a matter of them becoming
more adept, why would the predation slow down only when the school
ceased to exist? I.e., why would not the serpae tetras have become
able to evade the predators in my tank after seven had been
dispatched? One would think they would have gotten sufficient
practice by that point. But I think your reference to the
benefit/effort ratio has some merit. I think when a predator sees
several fish, he thinks his chances of catching one are greater
than when he sees just one or two. All this is just speculation of
course, but fun to think about.

Meph

Sometimes the prey does slip up, and gets to close to
> the predator's lunging range, so it's over. Often the prey grows
> large enough to discourage the predator (ie: the one feeder the
> Oscar never ate). Eventually the predators may forget the meal
> potential and become complacent about the 'hunt'.
>
> As your Electrics will vastly outgrow the adult size of a Neon,
> I don't think size will save those little guys. Your Electrics
> might be distracted by the need to hold the pecking order in
> place, and are currently satisfied with the amount of food they
> get from you. It might last, it might not.
>
> Drop something like a Nimbochromis livingstoni in there. These
> guys are highly food motivated (like the African version of an
> Oscar in this regard). I don't think they could ever forget
> about food ;~)
>
> NetMax
>
>

[NetMax]

"Mephistopheles" > wrote in
message nk.net...
> "NetMax" > wrote in
> :
>
> >
> > "Jim Morcombe" > wrote in message
> > ...
> >> Can anyone explain this behaviour?
> >>
> >> My comunity tank has loads of guppies, half a dozen angels,
> >> three Silver Sharks, and a lot of bristlenose.
> >>
> >> It also had seven Neon Tetras who usually stayed in one
> >> particular place in the tank.
> >>
> >> I bought my g/f seven juvenile Electric Blues and dumped them
> >> in the aquarium until Christmas.
> >>
> >> After the first night, had six tetras and they had changed
> >> their location in the tank.
> >>
> >> Each night the number of Tetras was whittled down until there
> >> were two left.
> >>
> >> However, these two are still there and have survived for a
> >> week.
> >>
> >> I don't seem to be losing guppies either, but this is difficult
> >> to verify.
> >>
> >> Why are the Electric blues leaving the remaining Tetras alone?
> >>
> >> Jim
> >
> > As the surviving prey become more adept at alluding the
> > predators, the benefit/effort ratio becomes smaller (basically
> > they are becoming too much effort to catch for the value of the
> > meal).
>
> Hello net max,
>
> You make some interesting points, as always. By the way, I asked a
> couple of biology professors about this behavior and neither one
> could really come up with a definitive answer. I think you may be
> onto something, but I am skeptical that it is the complete
> explanation. First, with regard to fish such as neon tetras and
> serpae tetras (the latter were the fish in my example), I am
> skeptical that they really become "more adept" at eluding predators
> -- I think they are just too stupid. Instead, they are pretty much
> always relying upon a hardwired instinctual toolkit when evading
> predators. Moreover, if it were just a matter of them becoming
> more adept, why would the predation slow down only when the school
> ceased to exist? I.e., why would not the serpae tetras have become
> able to evade the predators in my tank after seven had been
> dispatched? One would think they would have gotten sufficient
> practice by that point. But I think your reference to the
> benefit/effort ratio has some merit. I think when a predator sees
> several fish, he thinks his chances of catching one are greater
> than when he sees just one or two. All this is just speculation of
> course, but fun to think about.
>
> Meph
>
> Sometimes the prey does slip up, and gets to close to
> > the predator's lunging range, so it's over. Often the prey grows
> > large enough to discourage the predator (ie: the one feeder the
> > Oscar never ate). Eventually the predators may forget the meal
> > potential and become complacent about the 'hunt'.
> >
> > As your Electrics will vastly outgrow the adult size of a Neon,
> > I don't think size will save those little guys. Your Electrics
> > might be distracted by the need to hold the pecking order in
> > place, and are currently satisfied with the amount of food they
> > get from you. It might last, it might not.
> >
> > Drop something like a Nimbochromis livingstoni in there. These
> > guys are highly food motivated (like the African version of an
> > Oscar in this regard). I don't think they could ever forget
> > about food ;~)
> >
> > NetMax

It is interesting to speculate on. A similar behaviour can be seen when
fry mbuna start coming out of their rock hiding places. You wonder how
they can keep from being eaten. In reality, most were eaten, but the
survivors become very adept at staying out of range of the adults. It
seems like they develop a no-swim zone which occupies a spherical area
around every adult fish's mouth, facing forwards. They will wander
around the tank warily, and when an adult turns (so the fry enters that
zone), the fry will quickly jump away. Sometimes these little jumps take
place without the adult even showing awareness that the fry was close by.

There might be some parallels, but to compare mbuna fry to an adult
Serpae or Neon might not be fair. Mbuna fry (especially the
Melanochromis sp. IMO) are far more aware of their surroundings, and are
much more aggressive in their survival tactics, pushing their safety
envelope. Neons would have more of the survival instincts of a rabbit
being hunted by foxes, hide & wait, until they wonder why they were
hiding in the first place, and wander back out ;~).

NetMax