Synodontis a pleco killer?

[Sciencehero]

Hi everyone,

I hope you can help me. I picked up what I think is a 4-5" S. nigrita, and I'm wondering if anyone has heard of them being aggressive enough to kill off plecos? The pleco in question was about the same size and had been happily co-habitating with 2 other plecos, then I added the syno and 3 days later it's dead. I did notice the other day that the syno was slowly swimming after one of the smaller plecos, so is it possible he chased one to its death, or was otherwise responsible? There were no really obvious marks I would attribute to a fight on the pleco.

Thanks. I don't really want to have to get rid of "Bob".

[Birger]

I suppose it is possible but I would think unlikely...what kind of pleco's do you have and what foods have you been feeding?
Also is there enough cover for each fish to have its own cave,for the plecos and "Bob"?

Birger

[Sciencehero]

The tank is a 46 gallon bow heavily planted with a huge log that reaches from one side to the other. One of the plecos (Hypostomus plecostomus) lives in one end of the log. The other two plecos, which I haven't ID'd yet, would usually hang out under/near the log. I created a cave with rocks and some slate pieces, but none of the plecos seemed to care for it. When I added "Bob" I figured that there should be enough hiding places around the log and with the cave, so I didn't create anything else. For the first couple of days "Bob" seemed to tuck himself in one corner around a big crypt. I fed him some shrimp pellets yesterday, which he gobbled up pretty quickly, but otherwise left him to scavenge like the plecos. For the plecos I have been adding zucchini every once in a while, but haven't added any since Bob's arrival.

I have now added another piece of slate that I leaned up against the log to make a quasi-cave, and was thinking I could add a clay flowerpot in addition to the previously unused cave - should this be enough for everyone to get along? The previous tank that Bob came from also had a small clown pleco in it, and they seemed to get along fine (or at least the pleco was still alive).

Any advice is greatly appreciated - I really don't want to have any more losses, and I don't really have another tank that I can move Bob to, as they have livebearers whose offspring would likely become lunch.

[Birger]

but otherwise left him to scavenge like the plecos.

This statement worries me...not saying you are doing this but many people do not feed their catfish specifically, thinking the fish can "scavenge" food on their own, most plecos are grazers and more or less need a constant supply of food available to stay in good shape.

Sounds like you have enough structure for them to hide but the food issue is a concern.

Birger

[Richard B]

One of the plecos (Hypostomus plecostomus)

Is this correct?

In answer to the earlier question, i feel that in the confines of an aquarium there is definately the potential for a syno like this to bully other fish out of a preferential hiding spot or harrass a fish significantly where it shows unwanted intrigue/interest - either could contribute to the downfall of a pleco

[Sciencehero]

Birger:

There are quite a lot of other fish in the tank - rainbows, gouramis, tetras, a couple barbs and an angelfish - so there is food that doesn't get eaten by them that the plecos would get. I am giving them half a zucchini at minimum once a week, if not twice. If that is not enough, please let me know and I will up the food content. I will say that neither pleco looks emaciated, however I don't really know what a starving pleco looks like although I imagine it looks like anything else that hasn't gotten enough food.

Richard B:

Yes, there is an H. plecostomus (it was ID'd by members of this forum, so I am fairly confident about this) in the tank, but it is fairly small considering their max size (probably only 5-6"). Small enough to fit in the 4-5" diameter opening in the end of the log without difficulty. The smaller pleco is as yet unidentified, and I lost the one (the victim in the original post) that was closer in size to the Hypo. As I said, prior to introduction of the Syno all of the plecos got along well with each other and the other fish for over a year.

This morning "Bob" was underneath the end of the log near where the Hypo lives, and the other smaller pleco was upside down underneath the arch of the log (the log looks like an upside down V with another piece coming out of the point of the V), so hopefully they've picked their places more or less. In my prior post I said that there was already a cave that was not being used by any of the plecos, but I guess "Bob" isn't interested in it either. Or he uses it at night and by the time the lights in the tank go on he's already moved out of it. I have no experience with Synos, so I don't really know what to do with it which is why I posted here.

So the next question is how likely is it that my other plecos will share the same fate? And what should I look for to determine if they are being bullied?

[MatsP]

Id thread:
http://www.planetcatfish.com/forum/view ... 13&t=30123

The reason for the questioning is that A LOT of people buy what they think is H. plecostomus in shops, but they get the "common pleco", which these days is

Pterygoplichthys pardalis

- the Hypostomus species are quite rare these days.

--
Mats

[Sciencehero]

So are we now questioning whether the catfish in the attached thread is a Hypostomus plecostomus? Because that was me asking for an ID of the fish in question.

[MatsP]

No, I was just trying to explain why someone would say "are you sure" about saying that something is Hypostomus - and I posted a link to your thread, where it is clearly identified as Hypostomus - I can't see any reason to question that.

--
Mats

[Richard B]

RE; H Plecostomus

i was asking for a couple of reasons - common pterygoplichthys seem tougher than hypostomus when other fish have the desire to bother them & ultimately get bigger and sheer size can be off-putting to fish with an inquisitive nature (so i wanted to make sure) - plus hypostomus are really nice fish IMHO

[Sciencehero]

Update:

I think everyone has worked out the hiding places. Bob has displaced the Hypo from the end of the log, and I think the Hypo has taken up residence in one of the alternative slate caves I set up. I will continue to keep an eye on it, but if any of you can tell me what to watch out for to see if either pleco is being bullied that would be super.

Richard B: I think the Hypo is a nice fish too, especially in the light-coloured variation. I hope he doesn't get too big for the tank, because I don't really want to have to give it up.

I would still appreciate suggestions for feeding frequency for all of the catfish, and also varieties of food.

Thanks for the responses, everyone.

[Birger]

I would still appreciate suggestions for feeding frequency for all of the catfish, and also varieties of food.

It is hard to say until we know what you have for catfish...we know you have a Hypostomus and a Synodontis nigrita? but what is the other pleco?

Birger

[Sciencehero]

I have a couple photos I took not long after I first got the little catfish. Hopefully I took the ones you need for an ID. He's really hard to get photos of straight on, because he's very fast. If there's something specific you need a photo of to help the ID, let me know and I'll see what I can do.

[MatsP]

That's a

Pterygoplichthys pardalis

. It looks VERY skinny, which clearly means there isn't enough food in the tank - these fish are not shy about getting food, nor picky, so it must be lack of food in itself.

--
Mats

[Shane]

I picked up what I think is a 4-5" S. nigrita, and I'm wondering if anyone has heard of them being aggressive enough to kill off plecos? The pleco in question was about the same size and had been happily co-habitating with 2 other plecos, then I added the syno and 3 days later it's dead.

I think there are several possibilities here with the Syno chasing the pleco to death being less likely than other explanations. This can happen, but it usually takes weeks of bullying between catfishes for death to result and scratches, scars, and torn fins are usually noticed on the weaker fish long before they reach the point of no return.

I would say that it is more likely that some ailment was introduced with the new fish and I would watch the tank very closely to make sure this is not the case. It is also possible that the introduction of the Syno cut just enough into the food each fish gets per day that starvation of the weakest pleco took place.

If you have not already, I would get some veggies in the tank and start putting some weight on those plecos. The Syno may outcompete them for most of the dry or frozen foods, but that will be ok if they have something else to graze on all day.
-Shane

[Sciencehero]

Thanks for the ID, Mats. Are you thinking it's skinny because of the last photo? If so, I will take another more recent one to see if it looks the same. I didn't think it looked skinny from the top view, but maybe I'm wrong.

Shane, I did just add some zucchini to the tank yesterday, and both the Hypo and the now identified Ptery were on it within an hour. I will have to weight it down again as it is currently floating, however both are trying to eat it while it is at the surface.

Now we have the catalog of the fish in my 46 bow: Hypostomus plecostomus, Pterygoplichtys pardalis, and Synodontis nigrita.

In another tank I have what I think is a clown pleco (not sure if it's Hypancistrus L340 or Hypancistrus debillitera), and another currently unidentified catfish likely in the Loricariidae family.

[Birger]

It is also possible that the introduction of the Syno cut just enough into the food each fish gets per day that starvation of the weakest pleco took place.

This was my earlier concern...you may want to read the feeding articles by MatsP three posts above, you can get to the articles on the right side of his signature.

Birger

[Sciencehero]

I took some new photos of the Ptery so you can tell me if it still looks skinny.

[MatsP]

No, it doesn't look as skinny - if you see the "triangle" in the belly in the first photo, that's like seeing the ribs on a human body.

--
Mats