Aplysina fistularis, also known as the yellow tube sponge, is a species of sea sponge in the order Verongiida. Aplysina fistularis is a golden or orange-brown color with a conulose surface. The animal is abundant in the Caribbean, where it is commonly found in reefs of open water areas. This sponge was first described by the Prussian zoologist Peter Simon Pallas in 1766.