• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Dwarf Pencilfish bloated/deformed?

JBFUK

Member
Joined
8 Jan 2020
Messages
68
Location
Kent, UK
Quick overview. Planted 125L tank with a good sized external filter (Fluval 307). Injected CO2. Reasonably lean dosing. Water params ~ 50/50 RO/Tapwater (hardwater); GH 12, KH 6,NH3 0, NO2 0, NO3 ~20ppm, PO4 ~0.5ppm. PH between 6.8-7.8 depending on time of day (changes with CO2 levels). Livestock - 8x Dwarf Pencilfish, 1x Pleco, 3x Corey (small), 2x guppys, 2x black pahntom tetras, 12x Lambchop Rasbora, 10x Chilli Rasbora, ~40 cherry shrimp, various snails. Sounds like quite a lot but the rasboras are all tiny so have very little bio-load.


Generally the tank seems quite healthy, I change 30-40L weekly, clean eheim pre-filter with water changes and the canister filter every 1-2 months.

I've noticed a few of my pencilfish have a bit of a bloated stomach (probably 4/8). I'd presumed these were the females with some eggs. However, one in particular has become very bloated to the point that it looks deformed. I've also noticed that the female guppy looks pregnant even when she's given birth.


Having read a little about bloating I first thought dropsy but then they've been like this for weeks and I read that's often quite quickly fatal? The other options are worms, some other parasites, eggbound or some sort of genetic issue.


I'm attaching a few photos, sorry if they aren't clear but the fish don't stay still for long! Any ideas?
 

Attachments

  • IMG_3608.jpeg
    IMG_3608.jpeg
    698.5 KB · Views: 413
  • IMG_3615.jpeg
    IMG_3615.jpeg
    632.9 KB · Views: 146
  • IMG_3616.jpeg
    IMG_3616.jpeg
    880.4 KB · Views: 163
  • IMG_3617.jpeg
    IMG_3617.jpeg
    744.3 KB · Views: 144
  • IMG_3620.jpeg
    IMG_3620.jpeg
    665 KB · Views: 154
I had exactly the same problem as you earlier this week, but it was just one of my marginatus pencilfish. When I first saw her I thought it was just eggs so didn't worry, and then 2 days later I spotted her again and she was enormous. I netted her out and into a jug of tank water with epsom salts in for a bath, as I got some advice from my fellow fish friends that she could be bloated and this was a solution. Sadly I noticed once I could see her from above that she was already pineconing a bit, and after 15 minutes in the bath she didn't poop like she would if she was bloated, or improve, and I decided to euthanise.

My outcome wasn't very good so I'm not sure if I have much advice, maybe the epsom salts will work for you and I was just too late in treatment. When I researched it I didn't find anything, but I'm not experienced in fish diseases.
 
That's a shame, it sounds like this is a pencilfish specific condition then. As you say I couldn't find anything useful online and asking in a tropical fish forum also did not gain any useful help or guidance.

I have one female guppy in my tank and she seems bloated too, she looks pregnant even after having fry and sometimes poops long white poops or looks like she's pooping sand. I read that livebearers are often aflicted with worms. I wondered whether she has them and has passed them to some of the pencilfish.

I've now isolated the female guppy and one of the effected pencilfish in a quarantine tank. I'm considering treating them with esha de-worming medicines. I can't think what else to do and don't want to euthanise half of my pencilfish if they are possibly recoverable.

[Edit]

BTW I believe Nannostomus marginatus is the same as Dwarf Pencilfish? You didn't happen to buy them from Tropco did you? I wonder if it's a genetic issue with a particular batch.
 
Last edited:
I bought mine from Wholesale Tropicals in London, so don't think it's the same batch? Though they could be getting them from the same place beforehand.

@mort can you advise what to do with these affected pencils? I have no idea how to treat, but I think you should take all of the affected ones out and into the quarantine.
 
I think you should take all of the affected ones out and into the quarantine.
My current thinking was to test whatever treatment I'm going to administer on one as I hear they can be quite sensitive to medications. If there are positive results then treat the others, or potentially the entire main tank.
 
Hi, just for some more info, can I ask what you are feeding and how often? From a quick glance I think it could be that they are just aggressive feeders and are consuming to much. I've seen this with female pencils and don't know if it's specific to their sex or if the males are to busy to eat as much. You get a similar appearance in tetras if they are a little greedy and it can lead to diformity.
That would explain why they have been like this for some time without seemingly becoming ill and is a good thing to rule out first.
 
My current thinking was to test whatever treatment I'm going to administer on one as I hear they can be quite sensitive to medications. If there are positive results then treat the others, or potentially the entire main tank.
I think that's a good plan. I think there's a thread on here about pencilfish being sensitive to some meds.
 
Due to the different types of fish in the tank I feed a variety of different foods, twice per day. I mix and match the different foods rather than use them all at once each time I feed.
  • Frozen BS (defrosted/diluted)
  • Frozen Daphnia (defrosted/diluted)
  • TetraMin Baby
  • TetraMin Flakes
  • Tetra Micro Granules (mixture of small floating/sinking granules)
  • Fish Science Cory Tablets
  • API Algae Eater Wafers
  • Bug Bites (micro size)
It's interesting to hear that the females can over eat but I don't know what I could do to prevent this without starving the other fish in the tank? As you say the affected fish have been in this state for some time and don't appear to be sick - they just look rather odd and uncomfortable.

I haven't fed my quarantine tank today and I'll hold off for another day or two to see whether it makes any difference to the pencilfish I've isolated there.

Regards the sensitivity to meds, I'm not looking to use the API oil based treatments mentioned in that thread, I have procured eSHa GDEX and eSHa NDX which are both worming and anti-fluke products that are said to be filter, shrimp and snail safe. They seem to be highly recommended and many people say that they use them in a quarantine tank on any new fish before introducing into their main tank.
 
Last edited:
I had a good look at the pencilfish in quarantine to see whether there was any sign of her losing weight after 24h without food. I noticed she had a tiny white thread training from her. I’ve never seen these fish poop but it looked suspiciously like some of the photos I’ve seen of worms.

Did a water change and the pre filter also seemed to have a lot of these white threads. Think I’m going to give it another day without food and then start with the NDX treatment.
 
I had a good look at the pencilfish in quarantine to see whether there was any sign of her losing weight after 24h without food. I noticed she had a tiny white thread training from her. I’ve never seen these fish poop but it looked suspiciously like some of the photos I’ve seen of worms.

Did a water change and the pre filter also seemed to have a lot of these white threads. Think I’m going to give it another day without food and then start with the NDX treatment.

Could still be over feeding and constipation, this article goes into some depth, and offers some easy things to try:

 
I'll be slightly controversial here but I don't think it's constipation because fish are so saturated with water through osmosis that they don't get dry fecal pellets, so constipation is less frequent than reported (from what i have read) . White stringy poo can also just be a sign that they haven't eaten as their guts are covered in mucus which helps them, and us, push out our waste. Normally we don't see this mucus as it's covering the poo but when the fish hasn't eaten it can still pass this and it comes out stringy.
I think with these fish their gluttonous appetites have just made them fat and it will take some time for them to lose it.

Not feeding from the surface and changing the diet can help in certain situations but my gut says this time they have just enjoyed the buffet to much.

Edit. The above is based on the length of time they have been plump. I don't think constipation would last month's and signs of it tend to occur quickly.
 
Last edited:
Marginatus are the greediest fish I've ever encountered so far, as well as being bold and clever, so they will always eat more than the other fish. They will happily chase away other fish to get to eat extra and when I put a new type of food in the tank they seem to instantly work out how to eat it (just recently added some stick-to-glass food, none of the other fish could work out how to eat it out even that it was food but the pencils were there chomping immediately). They know the sinking food on the bottom is just as good as food in the water column too.

They are so greedy and bold that when I put my hands in to do maintenance they will swim up to my arms and try to eat the little bubbles that appear around hair follicles! I can feel them nibbling me 😂

Their hunger is compelling but it's clear they shouldn't be fed as much as they'd like, it is a challenge to balance feeding them and the other fish in a community tank because of it tbh. I wish there was a good all the other fish liked that they didn't lol
 
Marginatus are the greediest fish I've ever encountered so far, as well as being bold and clever, so they will always eat more than the other fish. They will happily chase away other fish to get to eat extra and when I put a new type of food in the tank they seem to instantly work out how to eat it (just recently added some stick-to-glass food, none of the other fish could work out how to eat it out even that it was food but the pencils were there chomping immediately). They know the sinking food on the bottom is just as good as food in the water column too.

They are so greedy and bold that when I put my hands in to do maintenance they will swim up to my arms and try to eat the little bubbles that appear around hair follicles! I can feel them nibbling me 😂

Their hunger is compelling but it's clear they shouldn't be fed as much as they'd like, it is a challenge to balance feeding them and the other fish in a community tank because of it tbh. I wish there was a good all the other fish liked that they didn't lol

To be fair I have some Embers that are similar - they have quite big bellies, whilst the rest of the shoal are tiny. It is always the big bellied ones that are at the front of the queue and last to be still picking food of the substrate.

The best way I have found to combat it is to spread the food around more instead of in one spot, and the smaller the food stuffs the better. For example when I feed newly hatched BBS, I pipette them in numerous areas of the tank. It gives all the fish easy and equal access, and means the greedy ones can't snatch everything in the first 5 seconds, and instead have to hunt around for it.
 
To be fair I have some Embers that are similar - they have quite big bellies, whilst the rest of the shoal are tiny. It is always the big bellied ones that are at the front of the queue and last to be still picking food of the substrate.

The best way I have found to combat it is to spread the food around more instead of in one spot, and the smaller the food stuffs the better. For example when I feed newly hatched BBS, I pipette them in numerous areas of the tank. It gives all the fish easy and equal access, and means the greedy ones can't snatch everything in the first 5 seconds, and instead have to hunt around for it.
This is my method too, spread it around as much as possible. I suppose at least they're getting some exercise when trying to get the food that way! As with your embers they're always first in and last out, just in case there's a little more somewhere...
 
Can understand what you're saying there @mort but the fish are in qt and op is saying they've not passed anything bar the slight bit of stringy white faeces which would indicate they're bunged up
 
Can understand what you're saying there @mort but the fish are in qt and op is saying they've not passed anything bar the slight bit of stringy white faeces which would indicate they're bunged up

It certainly wouldn't hurt to feed some live daphnia and crushed peas for a week to see if it helps, or to rule that out as the cause before starting any meds.
 
Can understand what you're saying there @mort but the fish are in qt and op is saying they've not passed anything bar the slight bit of stringy white faeces which would indicate they're bunged up

It does suggest that but could also be because they haven't eaten for 24 hours, so have nothing to pass. Either way I think your suggestion in post 13 is the way to go.

When we had some imports there were often white stringy poo's in the quarantine tanks. We knew these fish hadn't eaten for at least 3 days but checked them under the microscope as some fish were wild caught. Nearly always it wasn't anything sinister just fecal mucus. I guess that experience has changed the way I look at things. It was really common to see obese fish in customers tanks including quite a lot of bronze cories with double chins or cherry barbs that looked like zeppelins.

Hopefully a good poo will sort these pencils out but if it doesn't I think they might need fat camp.
 
Back
Top