awilks26 awilks26
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  • Joined: 27/4/2018 13:01
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  • Posted on: 16/11/2018 12:23
Fancy Tail Goldfish Attacking Black Moor. Advice needed. #1

I am currently having issues with aggression in my tank. I have a 90 litre tank with two oranda and a black moor, the tank has been set up for 8 months and the water parameters are fine (I am in the middle of cycling a much larger tank for them which should be ready in a few weeks). About a week ago the two oranda started 'attacking' my black moor. I then separated them for a few days (with a tank divider) and then put them back together yesterday. Within the day the oranda started chasing and attacking the black moor again. I have read online they do this when breeding but I am unsure this is what is happening, as the breeding aggression should only happen for a few days (according to online articles). I have had to separate them again until I can figure out what to do. It is very distressing for my black moor as its eyesight is bad and doesn't realise its being attacked until its too late and being pushed and nudged into something. I am worried it will become hurt then contract infections and die.

Please could someone give me advice on why this is happening and what best to do?

Thank you.
Fishlady Fishlady
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  • Posted on: 16/11/2018 13:27
Re: Fancy Tail Goldfish Attacking Black Moor. Advice needed. #2
Male goldfish will bother a female until she releases or reabsorbs her eggs. How long that takes is variable and can go on for quite a long time.

Unfortunately, due to the distorted shape of fancy species', it's not uncommon for one male to mistake another for a female due to the rounded belly and this can be a longer-term problem.

If this is breeding behaviour and not plain aggression the male doing the chasing will be likely to be showing breeding tubercles, which are small white nodules, typically found on the leading rays of the pectoral fins and on the gill covers, though in some cases they can be more extensive, appearing on all fin rays of the pectorals, on the head and even on the pelvic fins and body.

Whatever the cause of the aggression, if it's exhausting or potentially damaging the moor s/he needs to be separated from the others. However, if the moor is a female and is egg-laden, she may need a male's attention in order to actually successfully release her eggs.