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Marine Animal Encyclopedia

Pogonophoran Worm Siboglinum ekmani

Pogonophoran worms live inside tightly fitting tubes made of chitin, a substance that is also found in insect skin. The animal has an extremely long, thin body, like a piece of string, divided into different regions. The head end has a single tentacle, which can coil up when the animal contracts back into its tube. Behind the head end is a bridle, a raised ridge of tissue that runs obliquely around the body. The main length of the body is covered in small projections (papillae) and appears red under a microscope due to its blood, which contains hemoglobin. There is no gut and the animal feeds by absorbing dissolved organic matter from the water through the skin. The very end of the body has a segmented region with hairlike spines called setae that may help the animal to grip the sides of its tube.

  • Phylum Pogonophora
  • Length Up to 4 in (10 cm)
  • Depth At least 330 ft (100 m)
  • Habitat Mud
  • Distribution Temperate waters of north Atlantic