bloodworm

The term "bloodworm" can refer to several different organisms. It commonly describes the bright red, aquatic larvae of certain midge flies, particularly those in the family Chironomidae. These larvae are important food for aquatic animals like trout and salmon. Some of these midge larvae, like the "bloodworm" that lives in stagnant water, use hemoglobin as a respiratory pigment.12

"Bloodworm" can also refer to certain red, segmented aquatic worms belonging to the phylum Annelida. This includes freshwater worms like Tubifex, also known as sludge worms, which are used as food for tropical fish. Additionally, the marine proboscis worm Glycera is sometimes called a bloodworm and is used as bait for saltwater fish. Less commonly, it can refer to parasitic worms in horses.345