Originally Posted by SMB
All the off camera brands make lenses with Nikon mounts, Tokina, Tamron, Sigma.
Look at the used B&H photo site. You are looking for Dx format lenses. Not sure one lens does it all, kids, dog, fish tank...
The Nikon 18-200mm Dx VR lens has always been a good walk around lens. If you are looking to get serious about fish then a macro lens at some point.
Love my 18-200mm. Just an all around great lens. So versatile. The wife and I tend to travel a lot, including internationally, so space and weight are often important. The 18-200mm is perfect. Also takes great tank shots.