red wag swordtail/ghost catfish

Question
We just started with fish and we have two red wag swordtails.  I've noticed that one will disappear for a while, hiding in a rock.  When it emerges, its black fins seem to have faded to almost clear with a few black lines.  It spends a lot of time at the bottom of the tank and the other swordtail seems to follow where ever this one goes.  Is this normal?  Is he sick?  If so, how can I help him?
I also have a ghost catfish I am concerned about.  It will spend almost all day in a spot near the bottom between two plants.  He just swims in place.  Again, is this normal?

Answer
Hi Jamie;

The hiding fish may be a female and is trying to escape the attention of the male. Or, they are both males and the other fish is trying to bully the hider. As a fish hides it will sometimes fade in color to try to visually disappear and get a break. Swordtails are livebearers and the males are interested in breeding all the time. This is why it's best to have at least two females per male. It distributes their "amorous attention" between the group instead of just one female. Here is a web page with a picture of male and female platies. You can tell sexes the same way as swordtails;

http://fish.orbust.net/livebearers.html

Ghost catfish are schooling fish and they like to be in groups of 5 or more to feel safe and happy. They do stay in one spot and "hover" in the water, that's very normal. They love tall groups of plants so give him more cover with extra plants until you get him some buddies of his own kind.

Be careful in adding new ones though if your tank is still new and/or small. It may not be able to support more than what you have already. Here is my web page about new tanks to help you through this;

http://www.xanga.com/Expert_Fish_Help

At Your Service;
Chris Robbins