About Pseudobiceros bedfordi (Laidlaw, 1903)
Pseudobiceros bedfordi (Laidlaw, 1903) is a large polyclad flatworm, reaching an approximate length of 8 to 10 cm. It has a distinctive body pattern: a brown to black base background marked with multiple transverse bilateral pink lines that surround thousands of tightly spaced bright yellow spots, and pink undulating spots paired with stripes along the sides of its body. Its body edges are usually ruffled, and its underside is pale pink. A pair of erect pseudotentacles is located at the front of its body. This species is distributed across Indonesia, Malaysia, Kenya, Micronesia, the Northern Mariana Islands, Thailand, Australia, the Philippines, the Solomon Islands, Myanmar, and Palau. It lives on coral rubble and ledges in back reefs, coastal bays, and lagoons. Like all flatworms in the genus Pseudobiceros, P. bedfordi is hermaphroditic and has two penises. When mating, the two individuals fence with one another using their penises: each attempts to stab and inject sperm into its opponent, while avoiding being fertilized by the other individual. They can inseminate their opponent by injecting sperm into any area of the opponent's body that they are able to penetrate. After successful injection, spermatozoa travel through the partner's body toward the ovaries to fertilize eggs. This movement of sperm is visible through the worm's body tissue, appearing as pale streaks that resemble lightning jags.
