''Narceus americanus'' is a large millipede of eastern North America. Common names include American giant millipede, worm millipede, and iron worm. It inhabits the eastern seaboard of North America west to

Georgetown, Texas Georgetown is a city in Texas and the county seat of Williamson County, Texas, United States. The population was 67,176 at the 2020 census. It is 30 miles (48 km) north of Austin. Founded in 1875 from four existing colleges, the oldest of ...

, north of the

Ottine wetlands The Ottine wetlands or Ottine swamp is an ecosystem along the San Marcos River in and around Palmetto State Park in Gonzales County, Texas Gonzales County is a county in the U.S. state of Texas, adjacent to Greater Austin-San Antonio. As of ...

. It has a nearly cylindrical gray body, reaching a length of . They can be commonly found in or under decaying logs from March to October. When threatened, they sometimes curl up or release a noxious liquid that contains large amounts of benzoquinones which can cause dermatological burns. This fluid may irritate eyes or skin. Many other millipedes secrete

hydrogen cyanide Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an ...

, and while there have also been claims that ''N. americanus'' releases hydrogen cyanide, they are unsubstantiated. They do, however, excrete a substance that causes a temporary, non-harmful discoloration of the skin known as millipede burn.

Ecology and behavior

Diet

''N. americanus'' are detritivores, primarily consuming decaying wood and leaf litter. They have also been found to feed on deer scat and fresh fruit, preferring these to their typical diet when given the choice. Most feeding activity occurs at night.

Behavior

Though capable of releasing irritating and foul-smelling liquid from

ozopores An ozopore is the opening of a defensive gland present in some arthropods, notably in millipedes of the order Polydesmida spermatophore A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophores ...

, and females are able to store this sperm to fertilize eggs at a later time. Other millipede species may lay 20–300 eggs, but ''N. americanus'' lay just one egg in a nest made of chewed leaf litter and excrement. The female millipede will wrap herself around the egg and nest until it hatches several weeks later, producing a millipede with seven body segments and only three leg pairs. The number of body segments and leg pairs are increased with each molting, and there is no parental investment after egg hatching.

Photos

File:Millipede on floor.jpg, On floor, note waves of legs File:Millipede curled.jpg, Curled in defensive position File:Narceus americanus Curled.JPG, Defensive position File:Narceus americanus finger.jpg, On a finger File:Narceus americanus.jpg, Closeup of the head

References

External links