Bedford's Flatworm
Bedford's flatworm (Pseudobiceros bedfordi) is a brilliantly colored marine flatworm of Indo-Pacific reefs. It is best known for a mating behavior called 'penis fencing'.
Bedford's flatworm (Pseudobiceros bedfordi) is a brilliantly colored marine flatworm of Indo-Pacific reefs. It is best known for a mating behavior called "penis fencing".
🧬 Field Guide Specimen: Open Bedford's Flatworm in the CRV Science Field Guide to log the specimen, see its place among the Lophotrochozoa lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.
Penis Fencing: Who Becomes the Mother?
The worms are hermaphrodites and both carry two needle-like penises. When two meet, each tries to stab the other with its penis to inject sperm through the skin, a process called hypodermic insemination, and the one that avoids being inseminated avoids the cost of carrying the eggs. The behavior is a classic example of sexual conflict.
Warning Colors
Its bold colors, typically a velvety purple or pink body with yellow-orange stripes, are thought to warn predators that the worm is toxic.
Flatworm Body Plan
Flatworms are flat, soft-bodied animals with a gut that has only one opening. Marine polyclads like this one glide over coral using cilia and muscular waves.
Bedford's Flatworm at a Glance
| Property | Value |
|---|---|
| Scientific name | Pseudobiceros bedfordi |
| Kingdom | Animalia |
| Phylum | Platyhelminthes |
| Class | Rhabditophora |
| Order | Polycladida |
| Field Guide group | Lophotrochozoa: Worms, Shells & Allies |
| Diagnostic feature (Field Guide) | Bilateral body with no body cavity, ruffled undulating swimming margins, and a gut with a single opening. |
| Order | Polycladida |
| Mating | Hypodermic insemination |
See Also
- Natural selection — sexual selection and conflict
- Evolution — hermaphroditism and mating strategies