Sudden Fin Nipping

[dasisson]

Hi there,

I've had a very settled community tank for 8 months now: Neon Tetra's, Rummy Nose Tetra's, Albino Corydora's, Peppered Corydora's and Guppies.
However last week we purchased a Black Moor and introduced him into the Tropical tank. (Black Moor's can accommodate temperatures up to 22 degrees Celsius so there's no problem there.)
One of my Guppies has started attacking the Black Moor, taking a bite every 15 seconds and then spitting out bits of scales and fin. In fact this one has caused all the Guppies to get a little scittish.
It's horrid and really upsetting.

Has anybody experienced this? What's the solution? There's obviously some conflict going on,...

D.

 

[WILDER]

How many gallons is the tank.
Shouldn't really keep tropical fish with coldwater fish.

 

[Jazzzz]

er the blackmore can take warm water but should be kept at a cooler temperature also its a bit low for the tropicals maybe

also as he gets bigger he will start to eat your other fish

 

[dasisson]

How many gallons is the tank.
Shouldn't really keep tropical fish with coldwater fish.

Technically, Yes. Although if you look at acceptable temperature ranges for these fish varieties then there is some crossover.

 

[dasisson]

er the blackmore can take warm water but should be kept at a cooler temperature also its a bit low for the tropicals maybe

also as he gets bigger he will start to eat your other fish

Thanks for the comments Jazzzz.
Spending a little more time looking, it seems that it may be an issue over dominance on tank regions.
The Guppies tend to dominate the higher levels / surface level in the tank. Most of the others keep a strict lower to mid depth. As the Black Moor is fairly blind anyway, and as it has no preffered tank depth, then the Guppy seems threatened when the Black Moor encroaches on its vicinity or the surface, and reacts in this way.
However, it is still strange that it seems to be this one male Guppy only who is responsible for the nipping,...