They form dense forests which support a tremendous variety of animals both above and below the surface of the water. Mangals have provided many good fish for the aquarist, such as mudskippers and archer fishes. The mud that collects within the mangrove roots is a prime habitat for fiddler crabs, various clams, and snails. The temperate equivalent of the mangal is often said to be the salt marsh. These are tidal habitats, periodically covered by the sea.
Salt marshes are also important habitats, especially as the feeding grounds for seabirds and fishes.
Instead of trees, the major plants are grass-like. Gobies and sticklebacks are especially common in salt marshes, which are quite easy to explore and a good place to collect native fish and invertebrates for the aquarium. Unfortunately many salt marshes are threatened by agricultural or commercial development. Common to both the tropical and temperate zones, seagrass meadows are found in shallow water. Seagrasses are true plants and not algae, but have proved to be difficult to keep in aquaria.