A. nuda may refer to:Aaptos nuda, a sea sponge Achroosia nuda, a Brazilian moth Agrotis nuda, a synonym of Agrotis bilitura, commonly called the potato cutworm, a South American moth Alcadia nuda, a Cuban land snail Andrena nuda, commonly called the naked miner bee, a North American bee Anomoeotes nuda, an African moth Apostasia nuda, an orchid Astroboa nuda, a basket star Astrophytum nuda, a synonym of Astrophytum myriostigma, a Mexican cactus Avena nuda, commonly called the hulless oat or naked oat