Tube worms

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Tube worms
Christmas tree worm (Spirobranchus giganteus) on a coral colony

Christmas tree worm ( Spirobranchus giganteus ) on a coral colony

Systematics
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Subclass : Palpata
Order : Canalipalpata
Subordination : Sabellida
Family : Tube worms
Scientific name
Serpulidae
Johnston , 1865
Subfamilies
  • Filograninae
  • Serpulinae
  • Spirorbinae
A scallop encrusted with worm tubes .

The calcareous tube worms (Serpulidae, Germanized also "Serpeln") are a family that consists of about 80 genera . The species usually remain smaller than those of the related feather worms (Sabellidae). They live sessile in tubes made of excreted lime, which can be closed by a lid (operculum) made of horn or lime (see also operculum of snails for the composition ). The operculum emerged from a transformed tentacle. Calcareous tube worms live on tiny organic particles and protozoa, which they filter out of the flowing water with their tentacle crown.

features

The multi-bristle of the Serpulidae family can be recognized most clearly by the fact that they have both a tentacle crown and a tube made of lime, in which they differ from the Sabellidae and why they have the German name Kalkröhrenwürmer. Just like the Sabellidae, they are clearly subdivided into the body regions thorax and abdomen, which is evident from the inverted position of the bristles and a faecal groove. Likewise, like the Sabellidae, in their segments they also have a pair of anterior nephridia with a single exit for excretion. The calcareous tube worms are between 2 mm and over 10 cm long, depending on the species, whereby the calcareous tube can be several times the length of the worm. The thorax has 3 to 12 bristle-bearing segments, the latter in the genus Filograna . The number of bristle-bearing segments of the abdomen is between 10 in some small species and over 100 in larger species of the genera Laminatubus , Spirobranchus and Protula . The first bristle segment only carries notochetes .

The tentacles (radioles) of the calcareous tubeworms serve both to capture small food particles and to feed them to the mouth through the activity of their cilia , and as gills for breathing. For this purpose, blood is pumped into and out of the tentacles in individual, blind-ended tentacle vessels with alternating flow directions. From here the blood flows through the abdominal vessel to the end of the body and from there through the intestinal sinus, in the anterior section through a dorsal vessel and a circumoesophageal ring vessel again forward. Chlorocruorin dissolved in the plasma serves as the blood pigment in all species examined in this regard , but the red colored blood in the genus Protula may have erythrocruorin . A central heart is missing; the blood is transported by movements of myoepithelial cells in the blood vessels.

Spread and sample types

The triangular worm ( Pomatoceros triqueter ) lives in the Atlantic , Mediterranean , North and Western Baltic Seas . The post squirrel worm ( Spirorbis spirorbis ) also lives in domestic waters, as well as in the Atlantic, Arctic and North Pacific, in shallow water, but also at depths of up to 5000 meters . In the tropical Indo-Pacific the Christmas tree worm ( Spirobranchus giganteus ) lives in hard coral colonies of the genus Porites . The colorful tube worm ( Serpula vermicularis ) has a worldwide distribution .

Lime tube worms occur in large numbers in the Gulf of Mexico , on the Texas coast near Baffin Bay, and form a serpulid reef and in Bermuda serpulid atolls with diameters of up to 30 meters.

Fossils

The calcareous tubes of the Serpulides are fossilized well preserved. They have existed since the Middle Triassic about 240 million years ago. In the past they were more important as reef builders than they are today.

Genera

literature

  • Stanley J. Edmonds: Fauna of Australia, Volume 4A. Polychaetes & Allies. The Southern Synthesis 4. Commonwealth of Australia, 2000. Class Polychaeta. Pp. 249-256, Family Serpulidae.
  • Coral marine aquarium specialist magazine No. 20 tube worms , April / May 2003, ISSN  1439-779X

Individual evidence

  1. ↑ Olev Vinn & Harry Mutvei (2009): Calcareous Tubeworms of the Phanerozoic. Estonian Journal of Earth Sciences 58 (4): 286 ?? - 296 doi : 10.3176 / earth.2009.4.07
  2. ↑ WoRMS: 328604
  3. ↑ Deep sea symbiosis: methane on the menu , on Wissenschaft.de from April 3, 2020
  4. ↑ Shana K. Goffredi, Ekin Tilic, Sean W. Mullin, Katherine S. Dawson, Abigail Keller et al. : Methanotrophic bacterial symbionts fuel dense populations of deep-sea feather duster worms (Sabellida, Annelida) and extend the spatial influence of methane seepage , on Science Advances Volume 6, No. 14, April 3, 2020. eaay8562, doi: 10.1126 / sciadv .aay8562
  5. ↑ WoRMS: AlphaID = 129636
  6. ↑ WoRMS: AphaID = 129643

Web links

Commons : Serpulidae  - Collection of images, videos and audio files