Lobsters are well known and easy to identify as they are a common scavenger living among coral reefs and rock reefs.  They do well in all environments, however, live rocks would be ideal as that is where they take shelter and stay out of plain sight from predators.  Some lobsters have claws and some do not.  Lobsters are nocturnal and while they are active during the day, they are most active and visible at night.  They have long antennae to navigate and inspect their path.