Aplysina fistularis

Aplysina fistularis, commonly known as the yellow sponge or 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.
Description.
"Aplysina fistularis" consists of tube-like structures that arise from a base. Each tube is rarely over in clear water but can reach in turbid-zone reefs. The sponge has wide oscula and thin walls with ridged surfaces. Unlike the related species "Aplysina insularis", "A. fistularis" does not develop rope-like projections around its tubes, although it may show some tendrils branching off of them.
In popular culture.
In "The SpongeBob Musical", the popular animated character SpongeBob SquarePants is revealed to be an "Aplysina fistularis".