Speculation: So far the fishes you can fish are all 'mundane', so fictional fantasy-fishes might not get implemented. Also there are no seas (or oceans) in Icesus, so big whale-like creatures might not get implemented either. Climate might not support fishes that are generally found in warm (tropical) waters.
Suggestion: We are in need of a fish very much like sturgeon, so the biggest fish record at astug wouldn't just be a clone from sturgeon list. Crabs would also be nice additions.
Perhaps some sort of octopi, eels and squids might make their way into the MUD as well?

Another suggestion: deep-lake terraintype to the great lakes that dominate the south-southeast part of the valley.