Pics of rainbow cichlid before he got sick

I'm posting these pics incase it gives a clue as to whether My cichlid was actually a new world rainbow cichlid. Also I have other fish in the same tank and if they get sick it may help to know what to treat them with.

That was Spike befor he got sick, not a good pic I'm afraid. Wish I'd got more of him.
This is him after getting ill

i have no idea what that is

That looks like the later stages of dropsy when the scales start to pinecone and the fish is evidently bloated as well. If any of your other fish start showing ANY symptoms, isolate them immediately but in a large enough tank (at least 5-10 gallons depending on the size of the fish) and watch carefuly. If it looks like they are bloated or lethargic or their condition deteriorates in some other way, treat for internal bacteria. Also, in the PM you sent me, you mentioned he developed red streaks. this suggests to me that the water quality in the tank he was in was not the best. I suspect this happened because you isolated him in an uncycled tank. If you ever need to isolate a fish again in future, move some gravel from your main tank into the hospital tank at the same time or, idealy, have a small sponge filter running on your main tank beforehand and just move that to the hospital tank at the same time as you move the fish and also make sure you do daily water changes if you see ammonia or ntirIte spikes. Test daily while you are treating as the meds will kill off the good bacteria and may mean you need to do extra water chnges like I mentioned before (and this is also why you should isolate before treating so you don't cause a mini-cycle in the main tank).

Thanks sylvia but he developed red streaks before I isolated him. The hospital tank was actually a 20l bucket and he was only in it 1 night before he died. I've ordered some maracyn 2 incase the other fish show symptoms. Can't understand it really as the tank is about 5 months mature and stats are always fine