{{Short description|Species of bivalve}} {{Speciesbox | name = Atlantic pigtoe | image = Usfws-atlantic-pigtoes-hand.jpg | status = EN | status_system = IUCN2.3 | status_ref = <ref name="iucn status 16 November 2021">{{cite iucn |author=Bogan, A.E. |date=1996 |title=''Fusconaia masoni'' |volume=1996 |article-number=e.T8781A12931171 |doi=10.2305/IUCN.UK.1996.RLTS.T8781A12931171.en |access-date=16 November 2021}}</ref> | status2 = LT | status2_system = ESA | status2_ref = <ref name="fws">{{cite web|url=https://ecos.fws.gov/ecp/species/5164|title=Atlantic pigtoe (''Fusconaia masoni'')|website=Environmental Conservation Online System|publisher=U.S. Fish & Wildlife Service|access-date=20 January 2025}}</ref> | genus = Fusconaia | species = masoni | authority = [[Timothy Abbott Conrad|Conrad]], 1834 | synonyms = }}
The '''Atlantic pigtoe''' (''Fusconaia masoni'') is a species of [[bivalve]] in the family [[Unionidae]]. It is [[Endemism|endemic]] to the [[United States]].
It is a small freshwater mussel with a sub-[[rhomboid]]al shaped shell and an average size of {{convert|2|in}}. It prefers clean, silt-free, moderate-flowing streams with high oxygen content and gravel or coarse sand substrate. It typically occurs in headwaters in rural areas due to its preference for pristine conditions.<ref name="fws"/>
The Atlantic pigtoe relies on fish hosts to complete its larval cycle. The female releases sticky packets of [[glochidia]] (larvae) into the stream, which attach to the gills and scales of host minnows. The larvae stay attached to the fish in a [[parasite]] relationship until they fully develop and metamorphose into juvenile mussels, after which they drop off into the stream bed.<ref name="fws"/>
Its current range is restricted to [[North Carolina]] and [[Virginia]], although historically it occurred and [[Georgia (US State)|Georgia]] and [[South Carolina]]. It is listed as Threatened under the [[Endangered Species Act]] since 2021. Threats to the Atlantic pigtoe include habitat degradation due to water quality, water quantity, instream habitat, and habitat connectivity. As of 2019 there were 7 known populations.<ref name="fws"/>
==References== {{Reflist}}
{{Taxonbar|from=Q3017505}}
[[Category:Molluscs of the United States]] [[Category:Fusconaia]] [[Category:Bivalves described in 1834]] [[Category:Taxa named by Timothy Abbott Conrad]] [[Category:Taxonomy articles created by Polbot]]
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