Christmas tree worm
| Christmas tree worm | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Christmas tree worms |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Spirobranchus giganteus | ||||||||||||
| Pallas , 1766 |
The colorful spiral tube worm ( Spirobranchus giganteus ), also known as Christmas tree worm ( from the English "Christmas Tree Worm"), is a type of calcium tube worms (Serpulidae).
Habitus
The body becomes up to 10.2 cm long and reaches a diameter of up to 10 mm, divided into up to 200 segments. The body is blue to brownish in color and shows a typical collar at the transition between the tentacle rim and the trunk. The two conical, spirally wound gills or tentacle crowns of up to 25 mm in length in yellow, orange, red, pink, blue, white or brownish color are striking. The worms form long calcareous tubes with a single thorn on the opening side and a rounded calcareous lid ( operculum ) on a long stem with a pair of antler-hard runners and a few short thorns on the edges.
Way of life and behavior
The spiral tube worm lives in self-made lime tubes , which it never leaves. From the outside, only the two colored tentacle crowns or gills are visible, which have given the worms the American name Christmas tree worm due to their striking appearance . The lime tubes are mostly found in hard corals (often in brain corals ). Dead corals are also often colonized with Spirobranchus .
As a sessile bristle worm, Spirobranchus giganteus belongs to the Sedentaria group . Therefore no eyes are formed in the adult animal. The animals are food filter feeders, which filter plankton from the water flowing past with their mobile tentacle crown. In the event of disturbances that can be registered by highly sensitive sensory organs on the tentacles, the worm withdraws into its tube and closes it with a lime cover. This lightning-fast protective mechanism can easily be observed by recreational divers in tropical coral reefs. A slight fanning of water with the hand in the direction of the animals allows them to be entrenched in their tubes instantly. The tentacle crown is also used for breathing .
According to Nishi and Nishihari (1996), individuals of this species can live up to 40 years of age.
Environmental demands
The spiral tube worm lives in shallow, warm seas at a water temperature of around 24 ° C to 26 ° C. Here they occur in the upper euphotic zone in the sublittoral, i.e. below the dry surf zone .
distribution
The Christmas tree worm is found in the coral reefs of most tropical waters, for example the Indian Ocean, the Red Sea, the South Pacific, the Caribbean and the Gulf of Mexico.
Relatives and similar species are also found in the North Sea. Known is the tiny spiral tube worm Spirorbis spirorbis of the great density of seaweed, such as. B. colonized the Sägetang . The triangular tube worm ( Pomatoceros triqueter ) also inhabits numerous rocks, stones and mussel shells, e.g. B. in the Heligoland Felswatt .
Selection of Christmas tree worms in Dili , East Timor
Christmas tree worms from Papua New Guinea
Spirobranchus giganteus , Vieques , Puerto Rico
.jpg)
.jpg)
literature
- Meinkoth, Norman A .: National Audubon Society Fieldguide to North American Seashore Creatures. Alfred A. Knopf: New York 1998
- Nishi, E., Nishihari, M. (1996) Age estimation of the Christmas tree worm Spirobranchus giganteus (Polychaeta, Serpulida) living burried in the coral skeleton from the coral-growth band of the host coral. Fisheries Sciences, 62 400-403.
- Rouse, Greg W., Pleijel Frederik (2001): Polychaetes. Oxford University Press: New York 2001
