yeah - if I so much as see the black ones look at each other I attack them with a pointy stick.

before you start - I'm in no way racist, but I fail to see the point of black fish in a garden pond, because they are in no way ornamental.

They managed to procreate last year and now there are loads of baby black fish swimming about gobbling up all the expensive fish food that the pretty (i.e. visible) fish should be eating.