Dead fish :(

Question
I have a planted 5 gallon tank with 3 cherry shrimp (2 male, 1 female) and until a few hours ago i had a molly.  The molly in question died rather suddenly.  He was swimming fine this morning, but dead when I got home from work.  His dead body was unusual.  His eyes had popped out of his sockets and his fins stuck straight out, his mouth was open, there was discoloring (2 dots) on one side, an odd "puncture-like" wound on his chest.  

Now some history.  The fish is a young molly. Purchased from a reputable fish store. By young, I mean small, less than 1/2 inch.

I had added the 3 cherry shrimp to the tank about 3 weeks ago.  I went away for a week 2 weeks ago, When I came home I noticed my fish had a raised blackish bump/hole on his ventral side near the head. It was odd enough that I took a picture to see if I could see it better.  But behavior was normal very active and hungry.  About one week later he's dead. I tried looking up fish diseases, but couldn't find anything that seemed right. I was wondering if this was a congenital thing or a heart attack or stroke, based on his odd rigor mortis.

Thanks for your help.

Answer
It sounds like a fungus. The eye symptoms and dots sounds very much like a fungus. This is something that can happen from anywhere. The thing about fungus sometimes is that you often do not see much behavior changes but only the occasional external symptom. As for other possibilities, perhaps the shrimp did not like the molly. I know this sounds odd, as the shrimp as usually very timid but they can be very aggressive if the fish invades thier territory. If this is the case the symptoms are from wounds. However, I more suspect a fungus and internal parasite. The only way to have helped this would have been to treat it with medication. One thing about diseases in fish, they have characteristics but often the fish may not have all of the symptoms or may show signs that seem like it is something else. Basically, each fish is unique and there is not real way to say the symptoms or how each fish will react to the disease. I strongy suspect a fungus/internal parasite. This was likely caused by stress. Mollies are usually very strong fish but every once and a while some come along that just cannot handle stress well. I hope this helps. Let me know if you need anything else.