Shubunkin keeps gulping air after feeding

Hello!

I have a ~4” Shubunkin that I was keeping with a 4.5” Common in a 30 gallon tank (I know, it is overstocked due to the full size they can grow to). After what I believed to be a fluke infestation that resulted from me ignoring to gravel vac (the fish were flashing a lot and freaked out when prazi pro was added and gasped at the surface immediately after), I noticed my Shubunkin would be found floating at the top of the tank at night. I continued with multiple cycles (4) of prazi to ensure that the flukes were controlled, but this problem still persisted. I started doubting my aeration. I’m running 2 aquaclear 50s and 2 air stones which cause a decent amount of surface agitation. I wanted to know for sure, so I ordered a Salifert dissolved oxygen test kit. Sure enough, dissolved oxygen looked to be between the 8-12 ppm range, indicating that was not the issue. Even more so, the common never exhibited these behaviors.

I started to pay closer attention to my Shubunkin. After watching after every feed, I would notice that she would always gulp for a very long period after feeding. I use only sinking pellets (northfin and NLS) and I even tried peas to no avail. Then I tried fasting, which FINALLY resulted in no gasping and no bloating + floating. Great, so it seems to be related to feeding, but I can’t just fast all the time. I’m really not sure as to what the issue is and what I can do. Is it a behavioral thing or a potential disease? Permanent gill damage from gill flukes?The Shubunkin has literally no other strange behaviors or symptoms other than this.

My parameters for Ammonia, Nitrite, and Nitrate are all 0. These seems really suspicious since Nitrates should never be zero, especially considering I have no live plants, but I assure you my tank has been cycled and I literally never read any nitrates. I’ve used the API test kit and shaken it extremely hard for over 5 minutes and have never gotten a reading that looked over 5 ppm. I’ve also used various test strips (which are known to be less accurate in general) with the same results. I always test ammonia and nitrite to be 0 via API test kits. pH is at 8, dkH at 6/7, dgH at 6/7, temperature at 75 F. 40% water change a week.

After nearly 2 months of this issue, I have now separated the two with the Shubunkin in a 10 gallon quarantine tank temporarily. I’ve tried feeding spinach on a clip to potentially change her behavior, with no success so far (it’s only been a day to be fair). I’ve read the forums for similar issues, but mine seems to be pretty unique. Would love to hear any suggestions.

 

1. not sure, could have been dmg from gill flukes. did they both freak out when treated with prazi? i've treated two different store bought groups of comets and shubunkins, and they had no reactions to it. about a cap full in 20g.

2. you mentioned gravel vac, how deep is the substrate? deep substrate can develop anaerobic bacteria that consumes nitrates.

3. was the prazi diluted in a container of water then added to the tank, or added directly into the tank? did the shubunkin swim through the prazi when it was added?

 

1. not sure, could have been dmg from gill flukes. did they both freak out when treated with prazi? i've treated two different store bought groups of comets and shubunkins, and they had no reactions to it. about a cap full in 20g.

yep both did, I used 7.5 mL for 30 gallons. In the first treatment they both reacted by freaking out and darting everywhere. Did the same for the following treatments in the weeks following and no reaction. I read somewhere that if there is a heavy infestation, the fishes can encounter discomfort due to the large quantity of flakes having spasms.

2. you mentioned gravel vac, how deep is the substrate? deep substrate can develop anaerobic bacteria that consumes nitrates.

This also puzzles me, the gravel is about only an inch deep. I thoroughly clean it once a week now too and when I’ve tried to use the existing filter media to seed a new tank, there were no nitrates at the end of the cycle in the new tank either.


3. was the prazi diluted in a container of water then added to the tank, or added directly into the tank? did the shubunkin swim through the prazi when it was added?

it was not, but it was in a liquid form (prazi pro). The Shubunkin did not purposefully swim into it, but when it diffused across the aquarium, both fishes reacted.

 

As an update, it seems that putting spinach after feeding NLS pellets is working. It appears to have been a behavioral thing where she would gulp after feeding, perhaps looking for more food. Not sure why the spinach stops this behavior, but not complaining. Hopefully all continues to go well.

 

goldfish are carp which like to graze on vegetation. the spinach gives them something to graze on.