In order to be true to a Biotope you would only have a limited choice of livestock.IMO this would be the only downside. Ive been reading a book about marine biotopes and some of the tanks are spectacular.
From a equipment point, i would think a tide zone could be tricky. Near reef zones, lagoons, seagrass beds, mangroves, all biotopes that i think would be great to mirror in a tank.
The way a tank is arranged can mimic a biotope within a reef. A reef gorge, a rubble zone, a cave,
The idea of a biotope seems like a great idea to me. And to have it as realistic as possible you could mix preditors with prey.
Just a exsample: Your tank contains a small section of reef in the Maldives 10 meters down. The live rock in your tank forms a cave surrounded by soft substrate. A few branching stony corals grow on the rocks above the cave. Some fleshy algae that naturally occur at this depth and a few sponges have started to grow from the rock. Close to the side wall of the cave grows a population of soft corals ( Sinularia dura ) a species that forms broad lobes in the moderate light at this depth. Above the cave hiding within the small branching stony corals several pairs of yellow clown gobies thrive and go through their spawning rituals. They need to hide among the coral branches, as you keep a Spotfin lionfish that loves to feed on small fish and crustaceans. You also keep a pair of Yellowhead sleeper gobies, which are great diggers. They constantly take mouthfuls of substrate hunting for prey, also stirring up nutrients for th corals while keeping the bottom layer clean. Your last fish is a comet that will naturally take up residence inside your cave. The large fishes prevents you from keeping many crustaceans, but a coral banded shrimp does very well in and around the cave. A troop of hermit crabs works to control the growth of filimentous algae.
If you are thinking of a specific biotope, make sure your tank size and lights also meet the needs of the livestock. GOOD LUCK TO YOU, GREAT IDEA.
