A new species of symbiotic flatworms, Paracatenula galateia sp nov (Platyhelminthes: Catenulida: Retronectidae) from Belize (Central America)

作者：Dirks Ulrich; Gruber Vodicka Harald R; Leisch Nikolaus; Sterrer Wolfgang; Ott Joerg A^*

来源：Marine Biology Research, 2011, 7(8): 769-777.

DOI：10.1080/17451000.2011.574880

• Interstitial meiofauna
• intracellular symbiosis
• subtidal sand

Paracatenula galateia sp. nov. is a mouthless marine catenulid platyhelminth with bacterial intracellular endosymbionts. The worms live in shallow back-reef sands in the Belize Barrier Reef system and are distinguished from the four previously described members of the genus by their large size combined with a ribbon-shaped body and characteristic bipartite inclusions in cells, which are interpreted as sperm. The bacteria are presumed to be sulphur-oxidizing chemoautotrophs. They are found in bacteriocytes which fill the body region ('trophosome region') posterior to the brain, whereas the anterior part of the worm (rostrum) is bacteria-free. Phalloidin staining reveals a delicate system of subepitheliar circular and longitudinal muscles and dorsoventral fibres. The serotonergic nervous system consists of a brain at the base of the rostrum and longitudinal fibres extending both anteriorly and posteriorly, the latter being concentrated in a structure called the 'dorsal cord'.

• 出版日期2011