This is a list of organisms that spend part of their life cycle or of which part of their anatomy is underwater.

This list is incomplete; you can help by adding missing items. (August 2008)

Plants

Semiaquatic plants are those whose roots are wholly or partly underwater.

Mangroves, a type of woody tree or shrub growing in the mangal habitat, consisting of more than 50 species across 17 plant families
Members of the plant genus Taxodium (Plantae:Pinophyta:Pinopsida...)
- Taxodium distichum also known as the swamp cypress or bald cypress
- Taxodium ascendens also known as the pond cypress
- Taxodium mucronatum also known as the Montezuma cypress or Ahuehuete
Members of the plant subclass Alismatidae (Plantae: Magnoliophyta: Liliopsida: Alismatidae)

Animals

Semiaquatic animals are those that are primarily terrestrial but that spend a large amount of time underwater, either as part of their life cycle or as an essential behavior (e.g. feeding). Some marine mammals, such the marine otter, the polar bear and pinnipeds, are semiaquatic, while others, such as the sea otter, cetaceans and sirenians, are fully aquatic.