Molly Laying On The Bottom Of The Tank

[Xall]

I got a male dalmatian molly about 4 weeks ago, he was extremely active up until recently. He started swimming kind of upright, I read online this was a sign of stress so I used the API liquid testing kit. nitrates were a little high. Did a water change (It's been a few days since than now), the water is fine. But the molly still isn't improving. He's moving around less and less, even laying on his side at the bottom of the tank. When I walk past the tank he stops laying down and swims around a little bit. What's wrong with him? what do I do?
 
I have other mollies in the tank, as well as some guppies, platys, tetras, a pleco and some ghost shrimp. No one else seems ill.
I'm aware of the importance of a quarantine tank but I'm new to the hobby and didn't have one at the time of buying him.
He doesn't have ich and my tank is no where near "overstocked". It's 75 gallons and I only have a few of each of the fish I mentioned.

 

[Ch4rlie]

Seems rather odd really.
 
Can you give more specific water test readings. Am assuming ammonia and nitrite are at zero?
 
Maybe just an old molly or something along to do with stress, does it have curved spine or any other symptoms at all? 
 
Sorry can't be of more help really.

 

[Xall]

pH is 7.4 - 7.8
Ammonia/nitrites 0
 
Here's a picture. It doesn't look like it has a curved spine when it's swimming but I'm no expert.
The only other thing I could think of as a symptom is he looks like he uses his tail fin as little as possible. He moves his side fins a lot, but the tail he seems to only move when he's startled / has to. The tail fin isn't ripped or anything. Yesterday he ate a little bit
 

 

[Ch4rlie]

Difficult to see from the pic.
 
Does he have all his fins and tail intact?
 
Not sure if its the camera or the pic, but there seems to be a red mark just behind his eye?

 

[Xall]

Red mark is a bad phone camera. I'll get more pictures later if he survives.. I have to leave soon.
And yeah, his fins all seem to be intact.
He's still doing the same thing; laying on his side. I can see him breathing but it looks like normal breathing. When I come over there he swims a little bit and then lays on his side again.
 
I'm not really sure what to do with him. There's no other symptoms besides him being inactive and laying on his side.
Anything else I should look for that wouldn't be obvious?
Should I quarantine him? I would imagine at this point it might do more harm than good. 

 

[Ch4rlie]

I'd leave him, netting him may stress him out too much and tip him over the edge.
Reckon a case of waiting 24 or 48 hours to see if any improvements.
 
Cannot think of anything at the moment what may be causing this, I am no expert, in fact still pretty much a newbie really. 
 
Hopefully someone with experience with mollies may come along and give tips or better still a diagnosis, if any.
 
Will keep fingers crossed nothing too serious.

 

[Xall]

Thanks for responding Ch4rlie.
Here's more pictures. maybe someone will see something I didn't.

 

 

[petfishbreeder]

It could be due to water chemistry being different in your tank than the tank he came from. What is your water temperature set at? Fish will clamp their fins up if they feel cold so check your temperature and that of the tank he was in before you got him. Mollies do better with some salt in their water so I would recommend adding a teaspoon per gallon of rock salt (not table salt which has chemicals added to make it run easily) which shouldn't cause problems to your other fish.
 
The best option I think would be to move him to a quarantine tank using water from the tank he's in if you can rather than inflict any treatment on the other tank inhabitants.

 

[Meeresstille]

Is it just me or does his tail fin look chewed up. Could it be fin rot? Or could it be that he's being harassed by the other fish (any other male Molly fish)? Until you've got figured out what's wrong, I'd be doing water changes more frequently and keep the temperature around 80F.
 
(BTW if your nitrates are getting too high between water changes...are you doing good gravel vacs during the water changes, and are you changing somewhere between 30 - 50% of the water every week?)

 

[Xall]

Temperature is at 78°F
There were no male mollies in the tank besides him when these problems started. I recently got another male molly (Keeping the ratio of 3 females to 1 male) and haven't seen any kind of harassment going on.

 

[Meeresstille]

Do the tail fins of the other molly fish look like his? It's possible that him spending so much time near the bottom is causing his fins to fray from rubbing against the substrate. 
 
I'm also wondering if he may have organ damage, maybe he was returned to the store from someone who had high levels of ammonia or nitrite that caused this damage.
 
I don't know how to word it delicately, but you should not add new fish to a tank when you have a sick fish. If it is contagious you run the risk of losing the new fish as well. Also, new fish are best quarantined for at least 4 weeks and then added to your main tank. I don't mean to sound accusingly, I too have been guilty of not quarantining! 

  

 

[Xall]

Do the tail fins of the other molly fish look like his? It's possible that him spending so much time near the bottom is causing his fins to fray from rubbing against the substrate. 
 
I'm also wondering if he may have organ damage, maybe he was returned to the store from someone who had high levels of ammonia or nitrite that caused this damage.
 
I don't know how to word it delicately, but you should not add new fish to a tank when you have a sick fish. If it is contagious you run the risk of losing the new fish as well. Also, new fish are best quarantined for at least 4 weeks and then added to your main tank. I don't mean to sound accusingly, I too have been guilty of not quarantining! 

  

 
It's hard to see whether his fin is ripped or not due to the colors. All of the other mollies (including the newer ones) have full fins and are acting normal. If you think it would help I can get pictures of some others too.
 
It's possible that he was returned, but for the first few weeks after I got him he was very active. He was constantly trying to mate. It was so much that I'm almost considering that a symptom too.
 
That was delicately enough 

I know I should be quarantining my fish, I don't have a proper long term quarantine tank set up yet. It's something I'm working on though. My tank has only been cycled and inhabited for about 2 months, and that's how long I've been in the hobby. I'm a noob

 

[Xall]

I just found him dead - So I guess we'll never know now. After taking him out of the water I can see his fin is ripped. What do you think it was? Should I add a sponge prefilter to my filters intake? or was it another fish/disease.

Again, he was the only male molly in the tank at the time this happened. I'm just trying to understand so I can prevent it in the future.
 

 

[Meeresstille]

Sorry for your loss! Sometimes there are no answers to why. Maybe he had organ damage, maybe he had some sort of infection or parasite. Maybe it was something with the water he was sensitive to, as there is a lot more going on in a tank's chemistry than we can test for (or so I've learned). Just keep a close eye on the others and don't add anything new for a month, kind of like that tank being a QT now! 
 
I don't think a pre-filter would have helped your Molly. Pre-filters are good when you have fry that you want to keep from getting sucked into the filter, or shrimp (mine keep ending up in the filter, every time I think of buying some pre-filters they are sold out), or to protect the long flowing fins of Bettas for example.
 
Again, I'm very sorry your Molly died!

 

[Ch4rlie]

Ah, shame.

Sometimes these things do happen. I lost one of my fish when first started and never found out the cause.

Sorry for your loss.