What Happened to my Rosy Tetra

[GLAB]

This morning I found a sad sight in my 35 gallon tank. I had purchased 4 Rosy Tetras Dec 15th 2020 and this morning I found one floating at the top of my tank with what looks like a huge bite out of its lower abdomen between the Pelvic fins and the Anal fins. All Four appeared happy and healthy yesterday. I took a picture attached. All the fins are intact and the other three are still acting very healthy. Fellow tank mates are: 3 Black Tetras, 3 Neon Tetras, 8 Lampchop Rasbora's, 3 Bronze Cory's, 2 Otocinclus, one very small (about 1 inch long) bristlenose Pleco.

Any ideas ?

 

[Slaphppy7]

What kind of black tetra?
Phantom, skirt, neon?

That wound is strange looking...looks like it happened AFTER the death of the fish

All tetras need to be kept in groups, to make them comfortable and to spread any aggression

 

[GLAB]

The Black Tetra's are Black Skirt. I was also thinking it may have occurred after the death as well as the Rosy Tetra was floating at the top and provides an opportunity to access that area of the fish easier for a bite. But that's a big bite ! Even for a Black Skirt Tetra.

 

[Slaphppy7]

Yes, Black Skirts are known for nipping and aggression, especially when kept in too small of a shoal.

All tetras should be in shoals of at least 10.

The rosy may have been harassed to death, then predated upon after it was deceased.

 

[Colin_T]

The bite would have happened after the fish died.

The fish has a cloudy eye, appears to be covered in excess mucous and looks like the muscle tissue is a bit cream/ opaque. This could be a water quality problem or an infection.

Post pictures of the remaining fish.

Test the tank water for ammonia, nitrite, nitrate and pH.

How often do you do water changes and how much do you change?
Do you gravel clean the substrate when you do a water change?
How often and how do you clean the filter?

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Wipe the inside of the glass down with a clean fish sponge.

Do a 75% water change and gravel clean the substrate every day for a week or until we know what is going on. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens.

Increase surface turbulence/ aeration to maximise the dissolved oxygen in the water.

 

[GLAB]

The water tests I can perform are the following:

Nitrate <20 mg/L
Nitrite 0 mg/L
Hardness 150 (GH)
Total Alkalinity 300 (KH)
PH 8.0

I do a weekly water change of about 35% and rinse the sponge filter media every two weeks. I have two power heads for circulating the water. The water source is well water and I am in Arizona so it is quite hard and alkaline. Not ideal for Tetras however it is consistent.

I do not know how long the Rosy Tetra was floating at the top of the tank as I found it mid morning. If it passed in the early evening the day before it could have been floating for quite a number of hours.

I do vacuum the gravel with each water change and the power heads are pulling water through the under gravel filter.

Attached is a picture of one of the three remaining Rosy Tetras. Colors have always been good.

 

[Colin_T]

The black skirt tetra in the picture has something on its tail. Any chance of some pictures of that fish and the other fish in the tank?

 

[GLAB]

Sure, attached is a picture of the same Black Skirt. I notice that when the light comes on the Black Skirts color flushes out and a small amount of the pigmentation in the fins remains as black and is not consistent day to day. When the light is out, the Black Skirts color comes back in.

 

[Slaphppy7]

The water tests I can perform are the following:

Nitrate <20 mg/L
Nitrite 0 mg/L
Hardness 150 (GH)
Total Alkalinity 300 (KH)
PH 8.0

I do a weekly water change of about 35% and rinse the sponge filter media every two weeks. I have two power heads for circulating the water. The water source is well water and I am in Arizona so it is quite hard and alkaline. Not ideal for Tetras however it is consistent.

I do not know how long the Rosy Tetra was floating at the top of the tank as I found it mid morning. If it passed in the early evening the day before it could have been floating for quite a number of hours.

I do vacuum the gravel with each water change and the power heads are pulling water through the under gravel filter.

Attached is a picture of one of the three remaining Rosy Tetras. Colors have always been good.

Get one of these, ASAP...we need to know if there's any ammonia in your tank water: https://apifishcare.com/product/freshwater-master-test-kit

When you say you rinse your media, do you do it in tap water, or old tank water?

 

[GLAB]

Very Difficult to get the Neons but I did get one. Got the Lamb chops

 

[GLAB]

Get one of these, ASAP...we need to know if there's any ammonia in your tank water: https://apifishcare.com/product/freshwater-master-test-kit

When you say you rinse your media, do you do it in tap water, or old tank water?

I rinse in the same water I use for a water changes. It is well water so it is not chlorinated or fluoridated from a city water treatment plant. I have had the well water tested with the only issues being high PH and very hard. I realize this is not ideal for tetras but I try to keep water parameters consistent with the water changes.

 

[Slaphppy7]

I have a well, that I only use for watering or washing, I use city water for drinking/cooking/water changes.

I once tested my well water, out of curiosity, and discovered both ammonia and nitrAtes in it....strange, but true.

 

[GLAB]

Yes, I agree that well water can offer some surprises as to what it contains. I had mine tested a number of times to ensure i was getting consistent results from the test facility (ie seasonal changes as well) and the only negative finding was Arsenic. Apparently not uncommon in northern Arizona. The water was just above standards so I installed an Arsenic filter to remove that. Ammonia and Nitrates were not an issue and can certainly be a problem in farming areas due to runoff.

 

[Slaphppy7]

I still strongly advise getting the test kit I linked above, to test your tank water...IMO, it's an invaluable tool every FW fishkeeper should have....much more accurate than paper strips.

 

[Colin_T]

the remaining fish look alright.

just do a water change and gravel clean each day for a week to dilute anything that might be in the tank. Then go back to once a week water changes.