Sea worm may refer to one or several of the following taxa:

Taxonomic name Type Description Size (length)
Acanthocephala phylum parasitic worm ranges from a few millimeters up to 65 centimetres (26 in)
Annelida phylum segmented worms ranges from microscopic to 3 metres (9.8 ft)
Aplacophora Sub-phylum molluscs that look like worms a few millimeters to several centimeters
Chaetognatha phylum arrow worms 2 to 120 millimetres (0.079 to 4.724 in)
Cycliophora phylum found living attached to the bodies of lobsters less than ½ mm wide
Entoprocta phylum sessile aquatic worms ranges from 0.1 to 7 millimetres (0.0039 to 0.2756 in)
Gastrotricha phylum pseudocoelomate worms 0.06 to 3 millimetres (0.0024 to 0.1181 in)
Gnathostomulida phylum jaw worms 0.5 to 1 millimetre (0.020 to 0.039 in)
Hemichordata phylum deuterostome worms a few centimeters to 2,5 meters
Kinorhyncha phylum pseudocoelomate invertebrates, widespread in mud or sand at all depths 1 mm or less
Loricifera phylum sediment-dwelling worms 100 µm to ca. 1 mm
Micrognathozoa superphylum discovered living in homothermic springs 0.1 millimetres (0.0039 in)
Nematoda phylum round worms ranges from microscopic to 5 centimetres (2.0 in), and some parasitic ones reaching over 1 metre (3.3 ft)
Nematomorpha phylum parasitic worms 50 to 100 centimetres (20 to 39 in)
Nemertea phylum invertebrate ribbon worms most are less than 20 centimetres (7.9 in) long, one specimen has been estimated at 54 metres (177 ft)
Phoronida phylum horseshoe worms 2 centimetres (0.79 in), the largest are 50 centimetres (20 in)
Platyhelminthea phylum flatworms
Priapulida phylum penis worms, general shape may recall the shape of a penis 0.2 to 39 centimetres (0.079 to 15.354 in)
Sipuncula class peanut worms, a group of unsegmented marine annelids 2 to 720 millimetres (0.079 to 28.346 in)
Teredinidae family shipworms, which are marine bivalve molluscs several inches to five feet.
Xenoturbellida subphylum bilaterian worm-like species up to 4 centimetres (1.6 in)

See also edit