In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below.
Semiaquatic animals include:
- Semiterrestrial echinoderms of the intertidal zone, such as the "cliff-clinging" sea urchin Colobocentrotus atratus and the starfish Pisaster ochraceus
- Aquatic insects (e.g., dragonflies) with at least one nonaquatic life-cycle stage (e.g., adults), or amphibious insects (e.g., amphibious caterpillars or the ant Polyrhachis sokolova).[note 1] Members of the hemipteran infraorders Gerromorpha and Nepomorpha occupy a variety of semiaquatic and aquatic niches, with many of the former locomoting on the water surface; a few of these are marine (e.g., Halobates, Hermatobates).
- Semiaquatic springtails, such as Anurida maritima
- Semiterrestrial malacostracan crustaceans (e.g., many crabs, such as Pachygrapsus marmoratus,[note 2] some amphipods, such as Orchestia gammarellus, some isopods, such as Ligia oceanica and some barnacles, such as Balanus glandula)
- Horseshoe crabs are mostly aquatic but spawn in the intertidal zone; juveniles live in tidal flats
- Semiaquatic spiders, such as Ancylometes or Dolomedes (these are distinct from the almost fully aquatic Argyroneta)
- An amphibious centipede, Scolopendra cataracta
- Semiaquatic annelids, such as the earthworm Sparganophilus
- Intertidal bivalves, such as Enigmonia, which lives on mangroves
- Intertidal chitons, such as Acanthopleura granulata
- Semiterrestrial gastropods, such as the intertidal Patella vulgata, a limpet; also amphibious freshwater and marine snails, such as Pomatiopsis or Cerithideopsis scalariformis, respectively
- Semiterrestrial flatworms of the intertidal zone, such as the acotylean Myoramyxa pardalota
- Semiaquatic angiosperms (e.g., mangroves, water spinach, water cabbage, and the entire order Nymphaeales)
- Semiaquatic conifers, such as pond cypress
- Semiaquatic ferns, such as Pilularia americana
- A semiaquatic horsetail, Equisetum fluviatile
- Semiaquatic quillworts, such as Isoetes melanospora
- Semiaquatic club mosses, such as Lycopodiella inundata
- Semiaquatic mosses, such as Sphagnum macrophyllum
- Semiaquatic liverworts, such as Riccia fluitans
- At least one individual of a normally fully terrestrial praying mantis species, Hierodula tenuidentata, has learned to opportunistically prey on fish.
- Technically, most land crabs fall into this category, since most must return to bodies of water to release their eggs; the few exceptions, such as members of genus Geosesarma, are found among the Grapsidae (sensu lato) and Potamoidea (sensu lato).
- Battiston, R.; Puttaswamaiah, R.; Manjunath, N. (2018). "The fishing mantid: predation on fish as a new adaptive strategy for praying mantids (Insecta: Mantodea)" (PDF). Journal of Orthoptera Research. 27 (2): 155–158. doi:10.3897/jor.27.28067.
- Tan, C.G.S.; Ng, P.K.L. (1995). "Geosesarma notophorum sp. nov. (Decapoda, Brachyura, Grapsidae, Sesarminae), a Terrestrial Crab from Sumatra, with Novel Brooding Behaviour". Crustaceana. 68 (3): 390–395. doi:10.1163/156854095X00557.
- Burggren, W.W.; McMahon, B.R., eds. (1988). Biology of the Land Crabs. Cambridge University Press. pp. 53–54. ISBN 978-0521306904.
- Newman, L.J.; Cannon, L.R.G. (1997-06-30). "A new semi-terrestrial acotylean flatworm, Myoramyxa pardalota gen. et sp. nov. (Plehniidae Polycladida) from southeast Queensland, Australia". Memoirs of the Queensland Museum. 42 (1): 311–314. Retrieved 2018-08-14.