Glyceridae is a taxonomic family of worms. They are commonly referred to as beak -thrower worms.any of certain bright red, segmented, aquatic worms of the phylum Annelida. Included are worms of the genus Tubifex, also known as sludge worms (class Oligochaeta, family Tubificidae), which are used as a tropical-fish food. The proboscis worm Glycera (class Polychaeta, family Glyceridae) is sometimes called bloodworm. G. dibranchiata is found alongthe coast of Georgia and the southern atlantic islands.Gray's Reef National Marine Sanctuary, about 17 miles off Sapelo Island, Georgia, is home to a variety of strange creatures. The Glyceridae, or bloodworms, are ferocious epi- and infaunal polychaetes that prey upon small invertebrates. They are errant burrowers that build galleries of interconnected tubes to aid in catching their prey.