Kribs and corys

[DiscusIt'sWhats4DinneR]

i use a 29 gal as a quarentine for new fish. i have a pleco, a platy and a KRIB that would just exist in there along with the new purchases i would quarentine. putting those three fish at risk for disease? probably. but that is not the purpose of this thread.
(the krib appeared to be peaceful)
about 2-3 weeks ago i purchased 5 julii corys, 4 otos, 3 neons, and. 4 cardinal tetras.


after a week and a half in this tank i removed corys and otos to another tank.

cardinal tetras were seemingly healthy. (they displayed bright colors and ate.)after 3 days in the tank all 4 of the cardinals were dead. the neons were all alive and swimming. each time i found the cardinals they looked a little rough, missing tail fins and body meat. i assumed they had died from ammonia poisoning or rapid temp change syndrome, and eaten after death. i had bad luck with cardinals before. acclimating them to a different water, (probably with an emphesis on temperature) too quickly usually will wipe out these fragile guys. but something has made me think otherwise about what killed them.


a week ago i placed one 2" discus, 2 more julii corys, and 2 scarlet badis into the 29 gallon tank with pleco, platy, and the KRIB.
anyway, every fish looked healthy. 1 day ago in the morning i noticed an empty...munched cory body floating. cleaned up pretty well. no head or tail, just a hollow section without much meat. obviously the only suspect was THE KRIB. . This morning my blue platy was laying on the bottom, but very intact. CSI investigated concluding that there were signs of a struggle. his tail fins seemed a little chewed up. i looked at his body trying to kind something. one of his gills was opened up a bit and bloody, although i am not sure if he was like that or if i did it with the net. so i started to wonder about my water. maybe someone decided to get windex overspray or some chemicals into the tank. maybe i contaminated the tank.... Wouldnt the 2 badis be the first to go from bad water? or the discus? platys are tough...
did a +50% WC. removed the krib and placed in 10 gal with malawayan cichlid and evil betta. (malawayan cichlid terrifies the krib btw..)

lesson learned; dont trust kribs.

[DiscusIt'sWhats4DinneR]

i am just not sure about the cardinals though. i pulled them straight from the bag into 50-50 tank water to bag water. they sat in this less than 5 minutes before i netted them directly to tank. they were in small bag from lfs for ~3 hrs. they seemed very healthy for ~3 days until they all ended up dead one by one. i am curious why the neons were left untouched. they might have behaved differently. or perhaps the cardinals death had not to do with the krib.

do we think that he was only scavenging dead fish meat, or was he a violent killer?

[Rod Hay]

Well, sometimes w/ wild animals and fish, anything is possible. However, being as you only have one KRIB and not a pair, it may not be the culprit. (If it was a bonded pair that could be an entirely different story.) Do you see any signs of this Krib acting anti-social during daylight? Does he/she chase the other fish, or snap at them?

[DiscusIt'sWhats4DinneR]

i hear when they are paired and mating they become extremely territorial.

for a long time the krib was non aggressive towards other fish until today i saw him nip at a cory in the tank. i do not watch this tank very long, only really while feeding. so i am not sure how he behaves during daylight hours (or what he does at night.)

are kribs active at night?

ayway, i found a dead badis in the tank an hour ago. he was white and apparently dead for a while, but i am not sure he has been dead all day since i removed the krib, i cant remember if i counted both the badis this morning when i pulled out the krib or if he was already dead when i did it and just didnt see him. what is strange is that the larger of the two is the dead one. he did not have obvious visible damage although i did not examine very carefully. The platy that i pulled out had a chewed up tail fin but it wasnt too bad. his messed up gill may have simply been from me trying to turn him over with the net during examination.

either one of two things happened;
the krib got lonely, angry, and hungry so he broke out into a rage....

or i had bad tank water. possibly chemically (from cleaning sprays) or bacteria. But probably ammonia. this tank has been running ~6 months. i normally do water changes twice a week in this tank. i have been feeding small portions frozen krill/bloodworm for the discus and lots of flakes. probably neglected to do sufficient gravel vac/wc this week. i noticed brown algae on glass......going from bio load of 3 fish to all listed above and feeding heavy combined with insufficent water change probably made ammonia spike a reality.

one of my observations i have made with discus is that when they are in good water their first few top fins stay connected together by translucent "fin membrane" as i call it. when they are in bad water these things seperate, turning into a row of little individual spikes instead of a uniform curve of connected finnage. the discus in this tank did not have the connected fins, although he is eating hungrily and is doing exceptionally well, bold and not shy in the least bit, after only 1 week.

so to be on the safe side i performed yet another 50% wc today.
what dissapoints me is that i intended to move the discus to my planted tank by the end of next week. now i need to keep him in quarentine until near the end of this month.