Are you serious?
If so, I think a snapping turtle in your tank would make a great tank mate for your cichlids.
A SNAPPER WILL EAT YOUR FISH ..JUST A MATTER OF TIMEi know the common sense answer, was waitign for somone to tell me they have and its no biggie.
Water turtle's are one of the dirtiest animals to keep. They also need a place to get out of the water as well as a good light that they can bask in. Most water turtle will eat fish.
It is obvious to me that you are a newbie to fish and also I believe you may still be in school. The mix of fish in your tank is a little out of wack. I never recommend mixing Central and South American cichlids with african cichlids. Do you own any books on Cichlids? If not it would be good for you to read The Cichlid Aquarium by Paul Loiselle. You can find them on amazon.com used for around $15.00.
Lonny
I used to keep a softshell turtle with my mbuna. I had a rock for him to lay out on (rest on). They have a small mouth and you can limit growth based on tank size. Here is what mine looked like.
http://animal-world.com/encyclo/reptiles/turtles/images/SpinySoftshellTurtleWHTTu2_C1415.jpg
I had trouble feeding him, he lived for about 4-5 months in there, then i put him in a 400 gallon outdoor pond, and never seen him again. I believe he got out of the pond (water overflowed during rains, so easily could have) and walked to the creek which was about 20 feet away.
I saw these for sale at That Fish Place in Lancaster, PA the last time i went. Dont know how good of an idea it was, but it worked for me, I wouldnt put him in with anything but large mbuna IMO.
Let alone outgrow any common tank you put it in...A SNAPPER WILL EAT YOUR FISH ..JUST A MATTER OF TIME
The yellow bellied slider maxes out at 8" to 10"!!!