Both my L114 and L160 (both happen to be pseudas) likes to lie on their back with the stomach and mouth facing the air, is there any scientific explaination for this behaviour? A couple of my friends has the same experience with their plecos as well.
You don't need to worry.
I have seen Ancistrus and Hypancistrus lay flat on their back in caves, thought also that they were dead... actually must be a sign that they feel quite good...
The oddest behavior of any loricariid that I have owned belongs to my Pseudorinelepis genibarbis. The fish is always swimming around the tank, it looks like it is floating in air. The fish will take flake food from mid water as well. Wheh I first purchased the fish I was concerned because its behavior was contrary to any Loricariid that I have had experience with. After speaking to a few individuals who have owned this fish I have found out that it surely is a special character.
Mark
I'm glad this is considered normal behaviour as I often catch my L190 lying on his back in the slate cave he inhabits, he seems to just not bother 'hanging on' to the underside of the slate. I did think he was dead when I first saw it!