Unfriendly Fish

[tqfan]

fish in the tank to begin with: 6 neon tetras, 6 glowlight tetras, 12 guppies, 2 dwarf gouramis, 3 spotted catfish, 1 male siamese fighter, 1 black ghost knifefish, 1 red tailed shark

the problems started monday (29th jan)
1 neon tetra disappeared - noticed monday morning
1 neon tetra disappeared - noticed wednesday morning
1 neon tetra disappeared - noticed thursday morning

1 glowlight tetra has an eye missing - noticed monday morning

siamese fighter has had some of his tail ripped, as has 2 male guppies, and the siamese fighter also has a bite on his left pectoral fine, so he's not using it so much - noticed tonight

1 more glowlight tetra has an eye missing - noticed tonight
1 male guppy has an eye missing - noticed tonight

it seems to be happening overnight... can sit and watch them during the day, and there's no fighting.

my question - who could be the culprit??

 

[WILDER]

Red tailed shark.
How many gallons or litres is the tank.
Also shouldn't keep the betta with guppys he will see them as competition, and eat them or nip there fins.

 

[TheGodfather]

I would put money down to say it was the red tail shark... Very aggressive fish...

Ollie

 

[tqfan]

really?

he just swims ignoring the other fishes, he doesn't chase them.

why would he be doing it at night, instead?

 

[stang1]

You'll find that a lot of fish will attack at night especially with the lights off. Not sure why this is but it does happen.

 

[WILDER]

Need to look at your tank size as if it's to small the red tailed shark will be even worse as he want's territory.

 

[tqfan]

i think i might have mis represented the shark.

i've just been searching for it, and most places are referring to it as red finned, not red tailed. others are saying rainbow shark.

however, when bought, the shop named it as a red tailed shark.

he's also albino.

don't know if this makes any difference, though?

anyways, the sites i have checked, said it is only aggressive to others of it's kind, hence me only getting one.

the book i have also states that it is a peaceful community fish.

also read that they grow to 5-6 inches, and he's maybe half that, atm, and need about 30gallons.

is this true?

 

[WILDER]

They are aggressive to other fish, my sister had one and he lived up to his name.
40 gallon tank needed for red tailed shark.
How many gallons is your tank as a black ghost knife fish needs a large tank too.


http/species.fishindex.com/search.php?p=...%20ghost%20fish

Looking like your tank overstocked to me and this is why you are having problems.

 

[Erised]

The nipped fins in the siamese fighter and the guppies will be related to eachother. Bettas (siamese fighting fish) do often not tolerate fish with long flowing fins, which is why they should not be kept with other male bettas or male guppies.
The missing eyes could have been caused by the shark. They *can* turn out nasty and territorial, even if you don't see him misbehave at night. Why it happens I don't know. The fact that it's an albino makes no difference.. I assume this is the fish you've got: Epalzeorhynchos frenatum

quoted from above site:

This fish is often territorial and can be aggressive, particularly towards its own species, but also to others. This aggressive nature can become more apparent with age. It is not generally as aggressive as its relative the Red-tailed black shark, and it is not generally a good idea to keep more than one of these species together, except in very large tanks with plenty of decor, so that territories can be established without the fish being constantly in site of each other.

Depending on the size of your tank, this might also be a factor. Fish like the rtbs and the red finned shark often go more aggressive when they're in a tank too small for them and feel their territory is invaded frequently. My bet is that if you return the shark to the petshop and use any credit that might be given to get yourself a 5G tank for the betta and seperate him as well, things will be slightly better.

--edit--
Seems that bgks are aggressive as well. Did not know this, guess that would be the problem then.

 

[Gatorbait]

IMO, a rtbs shouldn't be kept with anything else in anything less than a 55g. They are just too aggressive.

 

[ox5477]

You'll find that a lot of fish will attack at night especially with the lights off. Not sure why this is but it does happen.

Alot of predators will hunt at night. It gives them the advantage over the prey because the prey cannot see the attack coming.

Though, it might also be that it is just swimming around at night, and feels something and just instinctively bites because it is spooked...idk

either way, def the rtbs causing the probs

 

[tqfan]

don't think the tank is over stocked, but thanks.

i'll keep an eye on the shark, see what happens.

 

[WILDER]

If you don't think it's overstocked, can you then tell us how many gallons the tank is or litres.

 

[TerraDreamer]

don't think the tank is over stocked, but thanks.

i'll keep an eye on the shark, see what happens.

Don't you just love people like this?

 

[The-Wolf]

1 black ghost knifefish
the problems started monday (29th jan)
1 neon tetra disappeared - noticed monday morning
1 neon tetra disappeared - noticed wednesday morning
1 neon tetra disappeared - noticed thursday morning
my question - who could be the culprit??

asked and answered