Don't buy this one here, see if you can find it cheaper, but Aqualog Vol. I is the Crenicichla series. Not much detailed info, but still helpful. Finding a book that detailed in Crenicichla with lots of info shall prove difficult. There is talk that Frank Wazel's notes and stuff might be made into a book. Whether or not if it will be in English is yet to be determined, or if/when they will make it. I'm definately looking forward to it if they do!!!