Currently this is the only documentary featuring Lake Malawi (compared to National Geographic's feauturing Lake Tanganyika) and while it focuses mostly on the cichlids feeding behaviors, it is fantastic when it comes to the information it provides and the fantastic video footage of our favorite fish feeding in the wild....
From the video of a S. fryeri masquerading as an algae eater to get close to prey to egg stealing cichlids to rock-scraping algae eaters to water-jumping fly eaters, this hour long "seminar" (as Ad Konings describes it...he's the narrator by the way) provides a great view of Lake Malawi for those of us who either missed out on Ad Konings's old VHS diving videos (which are no longer available) or who can't afford to take the trip to Lake Malawi ourselves...
My only cons were that the DVD menu was poorly made...you can't skip to different chapters in the dvd, only fast forward or rewind, and that there wasn't (or I don't remember seeing any at least) much info on the crustacean eaters (shellfish eaters) and not much info on the really large haplochromine piscivores like the Buccochromis species, Fossorochromis rostratus, Lichnochromis acuticeps, etc.
What this does provide is lengthy scenes discussing and showing the different mbuna feeding behaviors, Aulonocara eating behavior and some Haplochromine behavior (off the top of my head I recall the sandsifting haps, algae eater, & a few piscivores.
No lake in the world contains such a diversified and distinct community of cichlid fishes as Lake Malawi. Over the years Malawi cichlids, which are among the most colorful freshwater fishes known, have become very popular among aquarists as they are easy to maintain and breed in captivity. The total number of cichlid species in the lake is now estimated at about 1000, which is about 200 more than all the freshwater fish species of the North American Continent combined! And there is every indication that still more remain to be discovered. 
