Probably the simplest way of stocking a biotope tank is to choose a specific reef location and stock only corals, fish and inverts collected from that location. This approach is the broadest and least limiting, making it easier to find suitable inhabitants for your tank.
The waters around Florida and the Caribbean are home to forests of gorgonians, large patches of zoanthids, and swaying seagrass beds. Tanks showcasing Caribbean species often include gorgonians, zoanthids, macroalgae (especially Caulerpa sp.), and colorful Ricordia. Gobies, basslets, grammas, jawfish and pygmy angels are all at home in a Caribbean tank. Stony corals from the Caribbean are not usually available in the hobby, as their collection in and around Florida is restricted. Similar substitutes can be found in Pacific species, however. For example, if you were recreating a Caribbean lagoon and Diploria strigosa was not available, you could substitute the similar-looking Pacific species Platygyra labrinthiformis.
An example of a patch reef.
As the motherlode of biodiversity, reef tanks with a Pacific theme can take many forms, ranging from low-nutrient/high-flow tanks dominated by small-polyped stony corals to high-nutrient/medium-light tanks filled with Euphylliids, Acanthastrea and other large-polyped stony corals.
If you view a typical reef from the air, you will see it segmented into a number of specific zones, and any of these would be a welcome starting point for a budding biotopic tank. Starting from the shore, they are:
- Lagoons and Seagrass Habitats: Lagoon areas are characterized by large patches of sand. The water here is calm and usually rich in nutrients. Plate corals are scattered across the sand, as well as brain corals and Euphylliids. Patches of seagrasses can be sparse or stretch for miles, and act as natural filters for the sediments that wash from the shore.
- Fringing and Patch Reefs: Surrounding and often jutting into lagoons are rocky flats. Many stony corals thrive here, including Acropora, Montipora, Faviids and Porites. The image to the right is an example of a stony coral patch reef surrounded by sand.
- Reef Crest and Upper Fore Reef: These areas are characterized by very aggressive water movement, high light, extremely low nutrients and abundant planktonic foods. SPS corals like Acropora dominate here, where their thick branching skeletons can withstand the pounding waves.
- Deep Fore Reefs: This area is generally dark, with strong water movement and plenty of planktonic food sources. It is home to non-photosynthetic gorgonians and colorful Dendronepthya and Scleronepthya. A tank dedicated to these corals requires very little lighting, but lots of feeding and strong filtration.
Any of these zones would be simple to recreate and effective as a beautiful reef system.