Brown tube sponge

''Agelas conifera'', also known as the brown tube sponge, is a species of sponge. Its color is brown, tan, or greyish brown with a lighter interior. It is common in the Caribbean and Bahamas, and occasional in Florida. ''Agelas conifera'' contains bromopyrrole alkaloids, notably sceptrin and oroidin, and levels of these feeding-deterrents increase upon predation.