RAINBOW FISH STRETCHING ITS BODY IN "S" SHAPE

[sanchay]

I bought a pair of female rainbow fish (i did not know they were schooling fish until i put them in my tank....and after that i am not able to find rainbows anywhere)....they are around 10 months with me(quite happy...no stress)

recently(around a month) i am noticing one of the rainbow acting weird....the rainbow is stretching her body in a way that her body looks like an S from the top....she is being a little aggressive to the other rainbow sometimes(both females)....I am not able to take a photo or a video as they are really fast and quick....i only get their shadows in photos

the rainbow eats fine...and does not look stressed in anyways (she even grabs her food from my hands)...I do not see any kind of itch or worms or any weird symptoms on the outside including dropsy

the tank is well cycled and the readings taken 4 days back are
ammonia is 0ppm
nitrite is 0ppm
nitrate is around 10
TDS is around 200
pH is at 7

she does not have any fights with her tankmates (a pair of shubunkins and 2 pairs of mollies)

 

[Ch4rlie]

Aside from obvious stocking issues which will need rectifying but can do this at a later point.

The first concern is why your Rainbowfish is acting like this, it’s not a normal behaviour, it much more likely to do with water parameters or even water temperature.

So we will need a little more information to work with, first what test kit are you using?

What is the size of tank?

Does any of the other fish show the same symptom at all or any other symptoms like lethargic swimming, gasping, staying at water surface, red gills or clamped fins?

When does the Rainbowfish usually display the s shaped stretch, perhaps just after a water change?

How much and how often do you do weekly water changes?

 

[sanchay]

Aside from obvious stocking issues which will need rectifying but can do this at a later point.

The first concern is why your Rainbowfish is acting like this, it’s not a normal behaviour, it much more likely to do with water parameters or even water temperature.

So we will need a little more information to work with, first what test kit are you using?

What is the size of tank?

Does any of the other fish show the same symptom at all or any other symptoms like lethargic swimming, gasping, staying at water surface, red gills or clamped fins?

When does the Rainbowfish usually display the s shaped stretch, perhaps just after a water change?

How much and how often do you do weekly water changes?

idk man...my rainbow is active...but sometimes does this S shaped body (ONLY ONE OF THE RAINBOW)

i dont have a test kit....so i give it to the shop where i buy my fish products and they give me the results right away...they seem to use some kind of API kit....(the API kits here cost around 60$...my tank just costed 70%)

the tank is a 16 gallon (LXBXH 20x13x18)....the temps are constant around 25c

nah...other fishes are fine...no gasping,lethargy,fights,no diseases in sight...none of the other fishes are doing the S shape

the S-shaped body is kind of random....she does that randomly......no specific time....she never did this before....

i do a 30-40% change every 7-8 days