Help - vanishing fish

[cobraman]

Right. I've started an aquarium and it appears I have vanishing fish.

Two guppies have vanished and today I saw my small Red Tail Shark feasting on a white cloud mountain minnow. I don't know if he killed it or it was already dead but he pretty much ate the inners of the fish right in front of me within a minute.

I also also introduced a fairly large pictus catfish and the RTS will not allow him near any food at feeding time. So much so, that I have had to feed the catfish bloodworms so he can eat as they float on the surface. The RTS also absolutely hates my two zebra danios but they are so quick they can get to the food quickly.

I knew the RTS was a semi-aggressive fish but I didn't think he would eat guppies/minnows or chase everything in the tank.

Help!

 

[Colin_T]

Pictus catfish are nocturnal predators with big mouths. A 5 inch long Pictus will take a guppy without any issues.
If a fish dies the red tail shark will eat the body and so will the Pictus.

You need to check the water quality for ammonia, nitrite, nitrate & pH. And post some pictures of the fish so we can see if they have any diseases.

You can check the fish yourself for any cream, white or grey patches or films over their bodies. Look for clamped fins (fins that don't stand up normally), white spots on the body or fins. White lips, flared gills, breathing heavily, gasping at the surface.

 

[Demeter32]

Red tail sharks are not good community fish, especially with smaller species. Same for pictus cats as they often eat small fish. I'd not have white clouds nor guppies with the two relatively large bottom dwellers.

What is the entire stocking and what size tank is it? Did you cycle the tank before adding fish?

 

[cobraman]

Hi guys,

The rest of the fish look good and I checked the figures for nitrates, ammonia and PH and all good again. I've also done a 50% water change on Wednesday. The tank has been going for 6 weeks and was fully cycled when adding fish.

My other concern is the catfish isn't bottom dwelling, it stays aloft as it is scared of the red tail shark who chases it when it goes to the bottom of the aquarium. The only time it does bottom dwell is late in the evening when the lights are dim and the RTS tends to leave it alone then.

The catfish is also struggling to get down to the bottom to eat its sinking pellets as the RTS will not let it eat. Could the catfish have ate the guppy due to hunger? Also there is absolutely no remains of the guppy anywhere.

 

[Lunar Jetman]

As has already been asked, what size is your tank? If it's too small then the catfish and shark will compete for the same territory.

When you say it's cycled, what are the current water parameters?

 

[Byron]

You have some serious issues here, and the dying fish are one result.

First, re-home the Red Tail Shark. This species is aggressive, and while individual fish can exhibit this to varying degrees, they will frequently take a dislike to other fish. Clearly the pictus is not welcome, and if you do not separate these now, the latter is likely to be dead before long. It is now severely stressed which weakens it and this will only get worse; it is also under severe stress from being alone, it is a shoaling species and needs others. Pictus must have a group, at least five, but that means a largish tank (at least 4-feet in length) and we don't know tank size here. But this species will eat smaller fish so this may not be what you want anyway. Being highly active especially at night, it is not a good tankmate for any sedate fish either.

The RTS may have killed the smaller fish, that is not at all a remote possibility. As another member mentioned, the pictus will if it survives likely do much the same, but at this stage it is more likely the RTS.

When you give results of water tests, always post the numbers so members know exactly. "Good" is a subjective term and what you or a fish store employee considers "good" may be anything but good for the fish. We can only offer assistance when we have all the data to assess the situation, and that will help you more.

 

[cobraman]

@Lunar Jetman - Its a 140l tank.

 

[cobraman]

@Byron

Thanks mate. I'll give water figures in the morning - need to do another test I think.

I brought the catfish at the weekend and two guppies have vanished and one white cloud was dead (and eaten by the RTS). I am now assuming the catfish went for a midnight snack (after missing its own food as the RTS did not let it eat) and ate the two guppies and possibly killed the white cloud too but couldn't snack on it as the RTS ate it.

Prior to getting the catfish, the RTS has got on fine with the guppies, white clouds and corys. At dinnertime he lets everyone eat what they like and does not chase or bully any of the fish at all. He only used to chase the zebra danios but they ate regardless. Since I introduced the catfish though he hates him and is going to eventually kill him no doubt (the catfish is hovering at the top of the tank all day and only comes down at night when I think he has eaten two guppies).

So, I need to get rid of the catfish first and foremost. He's only come in at the weekend and two guppies have gone, one white cloud has been killed and the RTS hates him. Prior to the catfish joining the tank, every fish (including the RTS) have been fine for 6 weeks.

 

[Byron]

The pictus will be returned, good. It needs a much larger tank and more of the species, notwithstanding the RTS issue.

You need to return the RTs too. This fish attains 5 inches, and can get quite nasty as it ages. It took a dislike to the pictus, but this is almost certain to be repeated with some other fish in the future. Any substrate-level fish are a risk obviously. And a 4-foot long tank is minimum for the RTS. The "used to chase the zxebras" is indicative that all is not well; the RTS may be temporarily side-tracked but RTS have an odd dislike for striped fish, so this could resurface. It is not kind to the fish to allow this to play out.

With respect to the fish "being fine," this is something we cannot know. We should assume a fish will develop according to its species traits and behaviours. Hoping for a fish that is not "normal" doesn't often work out in the end, and abnormal fish are generally that way due to some problem induced by the environment. "Environment" here means everything around the fish that can affect its development and health.

 

[cobraman]

Last question before I call it a night.

I've just set up my old 20l aquarium and stuck part of the filter media from my existing aquarium into it and let it run for 2 hours with the heater on. Can I stick my catfish in this tonight on its own as I have a real fear I will wake up with no guppies left in the morning?

 

[Byron]

Last question before I call it a night.

I've just set up my old 20l aquarium and stuck part of the filter media from my existing aquarium into it and let it run for 2 hours with the heater on. Can I stick my catfish in this tonight on its own as I have a real fear I will wake up with no guppies left in the morning?

Yes, that should work.

 

[Colin_T]

There is another possibility. The Pictus brought in a disease that is killing the other fish. Also guppies are riddled with diseases and have all sorts of issues. But the fact is fish started dying shortly after the Pictus was introduced. Did you get any other fish at the same time as the Pictus?

When Pictus hunt and eat they swallow their food whole. If the Pictus went after a White Cloud Mountain Minnow, it would have swallowed it, not killed it and let the body sink to the bottom. The White Cloud might have died and sunk to the bottom and was then fed on by the RTB shark.

 

[cobraman]

@Colin_T

The pictus was the only fish I brought at the weekend and added to the tank. Since he was added, two guppies went missing completely and one white cloud was found at the bottom of the tank and I saw the RTS eating it but leaving the skeleton and head.

I've just checked both tanks and the pictus is still alive (in his own tank) and all the other fish in the other tank are alive and well (including the RTS which is still in that tank full of fish).

 

[cobraman]

All good now folks.

I removed the catfish and everything is alive and well. I have lost no other fish and the tank seems a happy place again. I've also just added 6 serpae tetra (what a stunning school of fish these are) and 3 yoyo loaches to the tank and they all seem to get on fine with each other.

The red tail shark seems to have formed a bond with the loaches and despite trying to implement his dominance for the first 10 minutes or so, he has found out that the loaches hold their own and aren't going to be bullied by him. Now they just swim along happily next to each other and explore rocks and plant life together. Even during feeding time the shark doesn't seem bothered at all that the other fish are eating and just munches along with the rest of them in a calm state.

 

[Byron]

It would be better to research the fish species before acquisition. As I tried to point out previously, what seems OK to you (the aquarist) does not mean it is at all OK with the fish. You are not going to change what is programmed into the species' DNA.

Yo-yo loaches need a group of five (or more), and are too large for this sized tank anyway. And I will guarantee they and the RTS are not going to live peacefully for long, although given the circumstances it is always possible they will bee stressed by those and not act normally, but that is not good news either because it opens the door for health issues.

The Serpae Tetra need a group of at least 8, though 10-12 are better, and in a 30 gallon tank to themselves. This species is notorious as an aggressive fin nipper. When they get settled, again assuming they are normal, things will start to happen. Fins will disappear to start.