Guppy Murder - Whodunit?

[Daisy]

So, yesterday I bought 6 lovely fancy guppies for my 38 gallon tank.

Today, I have 4;  2 of them have clearly been murdered, and are at the bottom.

This is supposed to be a tank full of friendlies!

Other fish include rasboras, platys, bolivian rams, corydoras, serpae tetras, and an upside down catfish.

I'm thinking the culprit is either a tetra  (?), or maybe the catfish (if he comes out at night, when no one's looking).

Or the rams??

If it's the catfish (who is only 1 inch long), then I'm thinking I should remove him.  He was billed as a community fish... but I'm wondering if he just slipped in under the wire, on that one.

In sum, I'd rather remove the murderer than the remaining 4 guppies.

Thoughts?

[Toss]

If they died not long after you purchased them, there is a chance that they were already dying when you get them.

[Daisy]

A reasonable guess - but no, these two guppies were chomped nearly in half. 
Hmmm.

[mkowals2]

After they died did several hours pass before you found them? I this case, other tank mates could have just had a bit of a snack before you were able to remove the body. I recently found a dead tetra in my tank with it's stomach all wide open, and I was told that might have been what happened to it.

Hope that helps,

-Mike

[Daisy]

Ah - a possibility, I suppose.

The gory details are that I found the two guppies on the bottom of the tank, still alive, with their tails virtually missing (not just nipped - gone).  So, they could not swim.  (I have since quickly resolved matters for them.) 

This happened overnight, while lights were out.  So, some time could have passed before I found them.  When lights were on yesterday, for several hours, I did not see any aggression toward them by other fish.  (Except danios chasing them a bit - but they are too small themselves to do anything too grim.)

Because it happened overnight, I was suspecting the catfish.  But then again, he's a bottom dweller... and the guppies are top swimmers.

So it COULD have been natural death, followed by others chomping on their tails... but that seems less likely to me than murder.

!

[Fishnut]

I'm confused...did you find them dead with missing parts or alive without tails?  Also, when you listed the other fish, you didn't mention the danios that were in a following post.  Exactly what fish are in the tank?  What kind of rasboras?  What kind of Danios?

Most danios aren't good tank-mates for fish with long flowy fins like guppies.

[Lancaster]

Going from what you've listed for being in the tank three fish jump to mind as possibly problematic for the guppies:

Bolivian Rams:  I'd say that although they are pretty gentle for cichlids they can still provide some harassment for gentle fish like guppies.

Serpae Tetra:  Notorious fin-nippers; I've watched as my school of serpae bullied my far more expensive school of Emperor Tetra to death.

Upside-Down Catfish: There's a bunch of different catfish that all go by this name, the most common is "Synodontis Nigraventris" who gets 4 inches long, shouldn't really be alone, and will come out at night to eat whatever fits in its mouth.  I've actually seen tanks where these were put with cichlids to eat the cichlid fry and eggs in order to keep the adults from fighting.  If it's not S. Nigriventris, then it could (depending on what it actually is) get 8 inches or more and have a far more predatory disposition than S. Nigriventris.

My guess (if it was a case of fish-on-fish attack) would be that the catfish was the culprit, based on the timing of attacks and type of damage (large chunk of body missing as opposed to fins being picked at, these catfish tend to be gulpers).  It is possible though that once the guppies were incapacitated, another fish, like your rams, came and made the wounds worse.

Edit: I'd like to recant on the "gulper" comment, I was sort of creating a false dichotomy between "nippers" and "gulpers"  the catfish would bite, and because they have a larger mouth than say, the tetra, they'd take a bigger "gulp" of fish and water.

[Daisy]

Thanks to you both.

Yes, I'd initially forgotten to mention the Pearl (?) danios. (I initially bought them to help cycle my new tank; I gave 4 of them away, but I still have 2 in the tank, only because I cannot catch them!) The rasboras are Harlequins.

I found the guppies alive, but only barely, missing their entire tails.

Since the initial incident, I've had no more losses - the other 4 guppies are doing well.   I think you might be right about the catfish though - and it worries me to hear that he'll get that big.  Yet again, a bit frustrating that he'd have been listed at the fishstore as a community fish, if in fact he comes out at night and eats anything he can catch.  And I've also read that he should not be kept on his own - but since he's an addition that I now regret, the only thing worse would be 2 or 3 of them.  I think my plan might be to return him to the store... !

More generally, I'm not sure I'm cut out for the harshness and brutality of fishkeeping :-)  (While I did not expect it, it turns out that I feel quite sad when my fish die, or worse, meet a violent demise!)

On another note -  in the last 2 weeks, I've lost 2 julii corys (which apart from the Rams, are my favourite fish in the tank.)  Natural deaths, there, I think.  But I've had the worst time trying to find juliis in ANY of the fishstores!   They always seem to be sold out!

Thanks for helping out with the guppy problem - I think you both helped reconstruct the crime, and got it right.

Daisy.

[sas]

Don't be too hard on yourself, we've all started somewhere in this hobby, had
our ups and downs and as long as you learn from your mistakes you'll
be fine.
You will get the knack of buying healthy fish, appropriate fish for your setups and
who to buy fish from. As I said we all took this route and it is a wondeful
hobby but it does take patience.

I'd be willing to put money on Tosss' explanation and that what you found were
just the remanents of a meal unfinished. Cycle of life in a tank. Weak fish are recognized
by healthy and subsequently eaten. Just my two cents.

[svetlana]

Just a question...  Do you have any apple snails or other larger snails?  Cause guppies will settle to the bottom of the tank when the lights go off.  I had a similar thing happen to me and I started to change their tank mates one by one until I really thought about it and came to the conclusion that it was the snails.  They were eating tails and taking strips of skin off the guppiesb back. 

[Daisy]

No, I don't have snails, though I'm thinking about an aquatic frog....!

Your snails must be pretty speedy, even to catch your sleepy guppies :-)   
Perhaps yours suffered the same fate as mine -  that is, caught by something else, and then finished off by your snails?

A fishtank is a pretty brutal place to live, no doubt about it!

[caretaker]

We should have a who-done-it poll!


LPS
snails
rasboras
bolivian rams
serpae tetras
catfish
bad water conditions