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Blood-Curdling Facts about Bobbit Worms
[Bobbit Worm Phylum: Annelida] [Order: Eunicida] [Family: Eunicidae] [Species: Eunice aphroditois]
It has several nicknames, including sand striker and trap-jaw worm, but the most common name derives from the infamous John and Lorena Bobbitt case in 1993.
This guide contains some chilling facts about bobbit worms, including how these lethal ambush predators kill their prey, where they live, and how these benthic bristle worms reproduce.
Eunice aphroditois Distribution and Habitats
The two main areas to find bobbit worms are the Atlantic Ocean, such as Florida and the Caribbean Sea, and the Indo-Pacific region.
Like many of the annelid species, they thrive best in the warm waters of tropical and subtropical oceans.
The bobbit worm also displays most of the typical characteristics seen in benthic marine worms.
Thus, they like to make burrows in sand or muddy reef flats that cover most of their elongated body while they patiently wait for prey.
Bobbit worms are most active around shallow reef zones when there is an abundance of small fishes. Even so, they are difficult to spot during the daylight because they remain buried in the ocean floor, usually near sponges or rocky substrates.
Data records suggest they can tolerate depths approaching 200 metres. But, common sightings tend to occur most between ten and thirty (30) metres below sea level (100 feet).
Pro Tip: Scuba divers will need sharp eyes to see a bobbit worm in their natural habitat. Unless they are actively hunting prey (such as at night), only the five short antennae will be exposed from the burrow as they try to detect a suitable meal.
Bobbit Worm Characteristics
Many polychaete worms (annelids) share some common features and behavioural traits. For example, the average size of bristle worms tends to be around ten (10) centimetres long (4 inches).
Still, fully grown bobbit worms can be much longer (up to one metre in total body length) and a lot thicker (up to 4 centimetres in diameter).
But wait - there's more:
The body is elongated and segmented, and they have chaetae (bristles) running along each segment. Still, one of the distinctive features of the bobbit worm (Eunice aphroditois) is its iridescent body colour.
This unique skin colouration changes with the angle of illumination. It also shimmers as a variety of metallic hues, including bronze, green, black, and purple.
What Do Bobbit Worms Eat?
A combination of two strong, scissor-like appendages (called mandibles) and six pairs of small maxillae is a deadly one!
The bobbit worm can easily snap them shut with extreme speed to grab their prey, often slicing the victim in half (like a bear trap).
They are "cunning" ambush predators that hide their body in different kinds of sediment on the seafloor.
Only their antennae are exposed. But, the worm is capable of lunging upwards with speed and ferocity to kill various marine animals, but especially:
- Crustaceans (crabs, shrimp)
- Cephalopods (octopus, squids)
- Fish (including carrion and decaying flesh)
- Other benthic invertebrates (soft-bodied polychaetes)
Interesting Fact: The feeding method of the bobbit worm is so vicious because they use sensory vibrations and chemical cues to kill almost anything that swims (or crawls) too close to their antennae. They can slice it in half or they can drag it into their burrow to be eaten later.
How Do Bobbit Worms Reproduce?
Accurate information about bobbit worm reproduction is limited. It's thought to be chiefly hermaphroditic, but they might reproduce sexually and asexually.
Sexual reproduction occurs between organisms that have both male and female organs. Hence, after two separate individuals exchange sperm, any fertilised eggs will start to develop into new baby bobbit worms.
Most of the free-living annelid worms can regenerate through asexual reproduction. Any piece that gets cut in half is able to regrow through a process of regeneration into a complete new worm.
Threats and Predators
The average lifespan of bobbitworms (Eunice aphroditois) is around five (5) years in the wild (estimated with some speculation for longer).
Other threats that segmented worms face include amphibians, aquatic insects, crustaceans, fish (e.g. triggerfishes, groupers, and wrasses), as well as some larger worms.
Yes... they are cannibalistic creatures!
Sea worms also face a wide range of human-induced threats, especially a loss of habitat, marine garbage pollution, challenges with invasive species, and vernal pools (the drying up of small ponds and streams).
Related Information and Help Guides
- Annelida Characteristics: Interesting Facts about Annelid Worms
- Echinoderms Facts and Species Information with Pictures
- Marine Invertebrates Examples List of Animals from A to Z
Pro Tip: The short video [2:07 minutes] presented by "Deep Marine Scenes" contains extra facts about bobbit worms with actual footage of these bottom-dwelling organisms in their natural environment.