ADF died VERY suddenly - Is this normal?

[PURP]

I had 7 ADF's, 16 mollies, 11 tetras, and one algae-eater; all of whom had been getting along great in a 50ish gallon aquarium. Last night, when I got home from work, I checked in on everybody and all were fine. After a two-hour nap, I checked in on them again and was very upset to find one of my froggies floating around (face-down) in the surface current. I was hoping it was one of those froggy things where they appear dead, but are not. No such luck... After poking him lightly several times, and finally scooping him out of the tank, I discovered that his body was rigid. Also, he had what appeared to be an abrasion under his left front arm. I have heard that these cute little guys are not the brightest, and frequently injure themselves, but is it normal that their clumsiness results in death? There was absolutely no indication that anything was wrong two hours prior.

[tgampper]

Sorry to hear about your frog
It is strange that the frog died so suddenly. Usually minor abrasions are not fatal. I am thinking the injury was a result of a concussion, which would not necessarily have any outward signs.

[PURP]

Thanks. They DO seem to smash their faces into the gravel after grabbing a breath at the top. They all do this: Swim up to the top at a somewhat leisurely pace, grab a breath of air, then dive quickly to the bottom stopping only after they crash land face first. Is this normal? Could this cause a concussion?

[tgampper]

Yes, that is a normal behavior. This behavior could be the result that is found in their larger cousins, the ACF. Most of the animals that prey on them are birds, so the amount of surface time would be quite limited, seems like a reasonable theory.

[PURP]

Thanks again Terry. I appreciate your input.