Nighttime attacks?

[ArtistGardener]

I have had problems keeping corys alive in my planted 55 gallon. I've lost at least five skunk corys and four albinos. In the past, I've asked for help with this and most people thought it was my water, but that is always good. Others blamed salt because of brine shrimp, etc. I just put in three albino corys after they spent three weeks in my 10 gallon quarantine (same water parameters). All three were perky little buggers while in the 10 gallon and for the first two days in my big tank. This morning, I found two of them dead. One is alive and hanging out with the lone big albino that's been in there for a month or so. One of the dead corys look traumatized with a bruised head. Could my clown pleco be doing this to them? He hides all day long and I rarely see him. I have witnessed him charge at my SAEs and platys when they try to nibble his algae tablets…. Every time I've lost a cory, it has been during the night. I am about ready to give up on that family.

 

[bettaowner]

It could be the pleco because they can be territorial

 

[The Trooper]

Isolate the pleco and add more corys, if the pleco is the culprit you may need to rehome him. I know i'd choose my corys over my plec.

 

[Abiduwhabi]

Yeah this is easy to test, just isolate him to a quarantine tank and see how it goes. I would also choose the Cory over the pleco, especially if it's causing troubles.

 

[Stotts]

Hmm funny you say that, last year I had a pleco that didn't really seem to care much for algae and just wanted to bother all the other fish, I had him removed and got another from my lfs

 

[Rivers2k]

SAE's are typically more aggressive I would blame them first. but yeah I would one by one isolate your other fish. What else do you have in there?

 

[ArtistGardener]

My stock now after losing the two corys:

2 SAE
1 clown pleco
1 dwarf gourami
5 platy
11 neon tetra
8 pristella tetra
5 harlequin rasbora
2 albino corydoras

I've never seen the SAE be aggressive to other fish but have heard of it. The tetras, platys and gourami don't seem the least bit interested in the corys. I may have to try the quarantine of my clown pleco. Such a long process because I would want to quarantine the new corys for a least two weeks before putting them in again.

 

[ArtistGardener]

I do so appreciate all the advice on this forum, by the way. So often, I don't know what I would have done without all the help on here!!!

 

[aqua_chem]

While both SAE and plecos can be aggressive, it's not generally the kind of aggression that leads to dead fish IME. Then tend to have a more "get out of my face" style rather than the "I'm gunna get you" mentality that usually leads to dead fish, with the difference being that fish that retreat aren't harmed in the former and pursued in the latter. I can really see either species harming a fish to the point of lethality.


What are your water parameters, and how old is the main tank?

 

[ArtistGardener]

Tank is over 6 months old, heavily planted. Ammonia-0, Nitrite-0, Nitrate-<5, pH-8.0, GH and KH both about 12. Like I said, they were fine in the 10 gallon. This exact same thing happened with two different sets of skunk corys. I assumed that I got bad stock, but both places I got them from where adamant that those fish were perfectly healthy in their tanks (and they seemed so in quarantine, too). I slow acclimate from the store to my quarantine and again to the main tank. In addition, both stores use city water from same area I'm from (8.2 pH). If it was a water issue, wouldn't I be losing other stock? I appreciate your help!

 

[josh7]

With a bruised sort of caved in head I would have to blame the pleco has a perfect mouth to cause that sort of injury. SAEs might chase fish but I don't believe they have right mouth or enough powe to hold down a cory as it crushes its head.

 

[Toad]

Is it possible there is a decoration issue? Some place they are getting stuck in?

 

[ArtistGardener]

No; I have plants, driftwood, but no tiny spaces.