Apistogramma fry development

[Sowah]

Hi guys,

I have two groups of apistogramma cacatuoides fry that were born in Jan and Feb this year. As I did not know they require frequent water changes to stimulate growth initially, I fed around twice a day of bbs and only changed 30% of water every week. It was too late until I realise you have to change almost 40% of water on alternate days.
The number of fry dropped tremendously from 80 initially to around 15 now (slowly over the past 4 months), the size for the remaining fry are only 1-2cm. I also observed some fry having damaged fish fin and looking fragile, I am wondering would the signs be due to the disproportional rate of development or there could be a bacterial outbreak between the fry? (but all other fish in the tank are healthy)

From the attached photos, it seems to me that the proportion of the eyes of the fish is relatively large when comparing to its body, which indicates developmental issue?

 

[Mike Wise]

Larger than normal eyes on fish typically indicates stunting. Stunting can be nutritional (quantity and quality of foods fed) or environmental (less than ideal water quality).

 

[Sowah]

Larger than normal eyes on fish typically indicates stunting. Stunting can be nutritional (quantity and quality of foods fed) or environmental (less than ideal water quality).

Thanks Mike, yeh it could be nutritional issue because there's a period when I only managed to feed on alternate days. Do you think the damaged fin would be due to stunting or fin nipping among themselves?

 

[Mike Wise]

Tail damage looks like it was caused by aggression.