"Critters" are a tuff one because many are hard to photograph due to their size or cryptic nature, which is why we use the "pictorial" guide format on our site. It allows folks to simply match a photo to the critter they've seen in their tank and they get an idea as to if it's a "goody" or a "baddie", so to speak. If it's one of those "it depends" critters, we gave it a "watch them" rating. Our ID guide will never truly be finished, as there are always new additions. In fact, we often have peeps send us specimens for photographic purposes since you never know who will end up with what hitchhiker.
Renee (Cranberry) and I are currently working on some other articles for our site's library, as our move interrupted the flow so to speak...