First Fatality: Juvenile Peppered Cory

[TOMatt]

Hi,
I lost my first Cory this morning. I have no idea what happened, and am hoping someone here might know.

Last night, everyone seemed healthy, swimming, scavenging, etc. This morning I find one juvenile peppered cory lying belly-up (dead) on the substrate. It looks like he has a red wound 2-3mm in size near the front of his belly, and his gills are red. I haven't seen any aggression in the tank, and enough of the food seems to sink to the bottom that they shouldn't be starving.

Everything else in my tank appears healthy.

Here's a brief overview, as it's a new setup:
20g Aquarium, pea gravel substrate (no sharp bits that i can see), mix of live and silk plants. 6 Dwarf Spotted Danios, 1 Dwarf Gourami, 2 Red Platies, 4 (now 3) Peppered Cories.

Levels are stable: Ammonia =0, Nitrite = 0, Nitrate = between 10-20, Ph 7.4. All with an API Master Test Kit.

Recent changes:
Oct 10: added 6 Danios and cycled tank.
Nov 7: Tank started recording 0 Ammonia, 0 Nitrites started the next day
Nov 11: added 4 Cories
Nov 17: added 1 Dwarf Gourami
Nov 26: added 2 Red Platies, a Wisteria plant, an Amazon Sword Plant
Nov 30: one dead Cory
I've been testing levels daily, and 3 or 4 days after adding the Cories and Gourami, the Ammonia has gone to .25 for a day before settling back to 0. Hasn't happened yet since adding the Platties. I assume this was just my tank adjusting for the added fish, and don't expect a 1-day reading of .25 would poison the Cory. Especially just one of them...


Any help would really be appreciated. Hopefully I can avoid repeating whatever happened, or address any disease that might have been the killer (although with that bellywound, i'm not thinking disease).

 

[TOMatt]

A friend just told me that their gills usually turn red when they die.

 

[Oceangirl]

That is a lot in a 20 gallon, I would switch to sand if possible. I know people love to say they do fine on gravel, but to see your cories on sand makes it all worth it! I was strictly a gravel person for a LONG while, now I only do sand. I am not sure what caused him to die suddenly, the wound could have happend from him getting stuck some where and pulling free, a fight with someone in the tank. Most likely he poked himself on something.

 

[TOMatt]

Thanks Oceangirl.
I'm thinking about changing to sand. The gravel isn't sharp, but it's dark purple. Sometimes the Cories are hard to see. I'm probably upgrading to a 40G tank in the new year, so i might just wait until then to change the substrate.

As for the wound, I think i've figured it out. A decoration had a plastic leaf that had been clipped off, but some of the stalk remained. Considering I found him right beside the decoration, I have a feeling he stabbed himself with the plastic stalk. I've cut it out completely, and checked all other decorations for sharp bits.

It was all my fault.

But a good reminder: CHECK YOUR DECORATIONS FOR SHARP BITS!

 

[Oceangirl]

use a panty hose? Ho is one I guess? Rub it across the decor or edges, if it catches it can cause fish injuries.