How big can a crawfish grow?

Are catfish social or solitary creatures? What are the measurements of a tetra pack? Does big shark depend on plankton for food? How many kinds of great white sharks? Do female zebra danios have more of an arch to their spines than males? Which color goes better with aqua black or brown? Why the depth of pond look less then its real depth? What type of cups keep water cold? How does the seahorse protect itself from it's enemies? What ocean does the bull shark live in? How long do trout incubate their eggs? Which is the only lake in the world that has sharks? What is the difference between a tropical and a freshwater fish? Why is black molly sitting on bottom of the tank? Does a bat eat fish? Can a adult piranha take care of a baby? Why does female molly splash water with her tail? How often should you feed outside pond goldfish? What covers the gills of perch? What is the average rainfall in the ponds and lakes biome?