Are ribbon worms Protostomes?
The protostomes include several invertebrate groups such as insects, spiders, lobsters and flatworms. The worm species studied here belong to a special group within the protostomes called the lophotrochozoans. Despite their obscure sounding name, lophotrochozoans represent more than one third of known marine animals.
Is a ribbon worm a flatworm?
The Curious Case of the Nemertean Coelom: Flat Worms, but not Flatworms. Phylum Nemertea, also known as the ribbon worms, are an interesting group that are closely related to Bryozoans (moss animals), Annelid worms, and Mollusks.
Are ribbon worms Cephalized?
Flatworms and ribbon worms have a head. This evolutionary development is called cephalization. This means that there is a true front and back end.
Why are ribbon worms called ribbon worms?
Nemertines are known as “ribbon worms” because of the great length of many species; the European nemertine Lineus longissimus has been known to reach 30 meters (nearly 100 ft) in length, although most are much shorter.
Are ribbon worms rare?
Gorgonorhynchus may be rare, but ribbon worms are found across the globe in marine, freshwater, and terrestrial environments. One is especially notable: Lineus longissimus, which has been measured at more than 30 meters long. “Actually, a Nemertean is the longest animal in the world.”
How is a ribbon worm different from a flatworm?
The ribbon worms have a long, muscular proboscis that is everted from the head of the worm to capture prey. It can be seen both retracted and extended in the worms shown here. Unlike the extensible pharynx of flatworms, the proboscis is not connected to the digestive cavity.
Are ribbon worms segmented?
Ribbon worms, or nemerteans, are a group of very unusual worms related to mollusks and annelids. Most ribbon worms live in the ocean, and some can grow to over 100 feet long, but are usually much less than an inch wide. Some species live on land or in freshwater. Unlike annelids, ribbon worms are not segmented.
What is the phylum of ribbon worms?
Nemertea is a phylum of invertebrate animals also known as ribbon worms or proboscis worms. Alternative names for the phylum have included Nemertini, Nemertinea and Rhynchocoela. Most are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies.
What is the function of the ribbon worm?
Ribbon worms use cilia lining their bodies to move within a mucus that they produce. The largest species of ribbon worm is the bootlace worm, Lineus longissimus. This species is native to the North Sea where it can be found among rocks.
Do ribbon worms live in the ocean?
Most ribbon worms live in the ocean, and some can grow to over 100 feet long, but are usually much less than an inch wide. Some species live on land or in freshwater. Unlike annelids, ribbon worms are not segmented.
Do ribbon worms have a proboscis?
Other ribbon worms have a branched, spaghetti-like proboscis instead of a barb, and secrete toxins onto captured prey. Sometimes, ribbon worms digest their prey outside their bodies and slurp up the soft tissue through their proboscis.