Entoniscidae

{{Short description|Family of crustaceans}}

{{automatic taxobox

| image = Hemigrapsus nudus from Coos Bay, Oregon, with carapace removed to show the entoniscid Portunion conformis - journal.pone.0035350.g001-F.png

| display_parents = 3

| taxon = Entoniscidae

| authority = Kossmann, 1881{{cite journal |author=R. Kossmann |year=1882 |title=The Entoniscidae |journal=Annals and Magazine of Natural History |series=5th series |volume=10 |issue=56 |pages=81–99 |url=https://www.biodiversitylibrary.org/item/94495#page/99/mode/1up |doi=10.1080/00222938209459679}} Translated by W. S. Dallas from {{cite journal |author=R. Kossmann |year=1882 |title=Die Entonisciden |journal=Mitteilungen aus der zoologischen Station zu Neapel |volume=3 |issue=1–2 |pages=149–169 |url=https://www.biodiversitylibrary.org/item/37448#page/159/mode/1up}}

| subdivision_ranks = Genera

| subdivision = see text

}}

The Entoniscidae are a family of marine isopod crustaceans in the suborder Cymothoida.{{cite web |author1=Chris Boyko |author2=Marilyn Schotte |name-list-style=amp |year=2011 |title=Entoniscidae |editor1=M. Schotte |editor2=C. B. Boyko |editor3=N. L. Bruce |editor4=G. C. B. Poore |editor5=S. Taiti |editor6=G. D. F. Wilson |work=World Marine, Freshwater and Terrestrial Isopod Crustaceans database |publisher=World Register of Marine Species |url=http://www.marinespecies.org/aphia.php?p=taxdetails&id=147118 |accessdate=August 18, 2011}}

Members of this family are parasites of brachyuran and anomuran crabs, living in their hosts' haemocoel. A small chitinised hole develops through the host's exoskeleton through which the isopod can communicate with the environment. The female isopod bears little resemblance to any free-living isopod, but the morphology of the larvae show their taxonomic affiliations.{{cite web |url=http://www.vims.edu/research/departments/eaah/programs/crustacean/research/parasitic_isopods/index.php |publisher=Virginia Institute of Marine Science |accessdate=August 18, 2011 |title=Epicaridea: the parasitic isopods of Crustacea |author=Jeffrey Shields}}