Fish Died Overnight, Only Found The Head?

SO ive had a neon dwarf rainbow fish that hasnt been doing well for a while, she was very skinny, stopped growing taller, only got longer but never fattened up, would stay near the surface. All my other fish (other praecox, neon tetras, and swrodtails are all healthy and showing no signs of stress) I had lost one neon previously showing the same symptoms, and did not respond to any treatments i had tried.

Anyways she died overnight and this morning all i could find was her head? Is it possible that my 10 neon tetras picked the carcass clean? I will continue searching for the rest of her, but i find it hard to believe anything else would separate the head from the body.
Filtration is a fluval 306, pool filter sand substrate, some driftwood and a lot of plants.

 

Update: i just found the backbone. I guess i have some carnivorous fish, this has been.......well..... odd.

 

The symptoms sound like wasting, being very skinny is a typical sign. It's m tuberculosis. They get nodules on their organs so other than being skinny, there are no other visable signs. Treatment for this condition is Kanamycin and vitamin B-6 for 30 days. And yes, neon tetras will pick a dead or dying fish clean. Not only are the tetras, but pirhannas are tetras as well.

 

so should i worry about the other fish contracting the disease after eating the dead fish?

 

Yes, it is a concern. I suggest you go ahead and order the kanaplex, from my experience it is a gentle medication so dosing with it won't hurt at all.

 

Absolutely correct. And the best way to give them the vitamins is to give them Hikari brand of freeze dried blood worms. They contain micro encapsulated vitamins. Give them a treat of them 2 to 3 times a week instead of their regular food.

 

I currently feed them san francisco bay brand blood worms, but will try to find the hikari brand locally. The staple food for the tank is a mix between cobalt spirulina flakes for the rainbows, and tetracolor flakes, and some tetra min pellets. Since it is a community tank everybody gets a little bit of each.

I see that the kanaplex is also an antibacterial, is there any risk of a minicycle?

I also forgot to add the details of the tank. 40g breeder, 6 swordtails, 10 neon tetras, and now 2 praecox rainbows.

I was hoping to add about 6 sterbai corys this week, but if im going to be dosing meds i guess i should hold off so i dont expose them to the tuberculosis. Thanks for all the help!

 

The Kanaplex will not interfere with the bacteria in your biofilter. It's specifically targeted to specific gram negative bacteria and unlike other antibiotics, it kills the bacteria by causing their outer membrane instead of preventing their cell division.

 

Awesome, thank you very much. Informative answers telling me why i need to do something, not just that i need to do it.