Hydroides norvegica
From Wikipedia, the free encyclopedia
| Hydroides norvegica | |
|---|---|
 | |
| Chaetopoda, H. norvegica is at bottom left. | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Clade: | Sedentaria |
| Order: | Sabellida |
| Family: | Serpulidae |
| Genus: | Hydroides |
| Species: | H. norvegica |
| Binomial name | |
| Hydroides norvegica | |
| Synonyms | |
|
H. norvegicus, Gunnerus, 1768 [2] | |
Hydroides norvegica is a species of tube-forming annelid worm in the family Serpulidae. It is found on submerged rocks, shells, piles and boats in many coastal areas around the world. It is the type species of the genus Hydroides.
Polychaetes, or marine bristle worms, have elongated bodies divided into many segments. Each segment may bear setae (bristles) and parapodia (paddle-like appendages). Some species live freely, either swimming, crawling or burrowing, and these are known as "errant". Others live permanently in tubes, either calcareous or parchment-like, and these are known as "sedentary".
This serpulid worm lives inside a protective calcareous tube. The worm has about one hundred segments each bearing chitinous bristles called chaetae. There are twelve to nineteen pairs of tentacles surrounding the operculum, which looks slantingly cut. The head of the worm protrudes from the tube and is surrounded by a crown of tentacles. It looks like a low, round cup, with a fairly small mouth in the middle, and 16 small teeth or beams around the head’s edge.[3] The worm grows to up to thirty millimetres long. The abdomen is red and crown is also red with white cross-bands. The operculum is either red or has two red rings. Two distinguishing features are the opercular whorl and the chaetae forming a collar.[3] The tube is white and chalky, about fifty millimetres long and two millimetres wide. It is thin walled with many curved growth lines on the sides. The surface is smooth and often has distinct growth rings. The tube meanders irregularly over the substrate.[4]
Distribution
This species is found in the Atlantic Ocean, the Mediterranean Sea, the Indian Ocean, the Persian Gulf and the Red Sea. It is found from the eulittoral zone to around 350 metres and is a true marine species. This is in contrast to the harbour fouling invasive species Hydroides elegans with which it is sometimes confused.[3]