Phylum Annelida:
estimated 22,000 species (2023). 17,000 (2016)
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This phylum Annelinda, from Latin anellus meaning little ring is also know as the segmented worms and includes species such as ragworms, earthworms, leeches and marine worms known as polychaetes. Species in this phylum have metameric bodies, which bodies are divided into segments called annuli.
The annuli are covered with tiny hairs called setae, which help the worms move. Too, each segment contains parts of the worm′s excretory, circulartry, reproductive and nervous system. The only parts not segmented are the head and the rear of the body.
The Annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms.
Taxonomy:
Kingdom:
Animalia
Phylum:
Annelida
Class:
Clitellate
more than 10,000 species (2023)
Marine, freshwater and terrestrial Clitellum worms.
Subclass:
Branchiobdellae
Freshwater leech-like clitellates that are ectosymbionts or ectoparasites.
Order:
Branchiobdellida
1 Family, 22 Genera, 150 Species (2026)
Subclass:
Hirudinea
Three Orders
Marine, fresh water and terrestrial leeches.
Order:
Acanthobdellida
Bristle-leeches
2 Families, 2 Genera, 2 Species
Order:
Arhynchobdellida
Proboscis-leeches
13 Families, 47 Genera, 300 Species
Order:
Rhynchobdellida
Proboscis-less leeches
3 Families, 60 Genera, 370 Species
Subclass:
Oligochaeta
10,000 species (2023)
Marine, fresh water and terrestrial worms (earthworms).
11 Orders, 30-43 Families, 5,000 to 10,000 species worldwide
Order:
Alluroidida
small aquatic and/or semi-aquatic worms
2 Families, 9 Genera, 14 Species
Order:
Capilloventrida
minute, primitive aquatic worms
1 Family, 1 Genus, 5 Species
Order:
Crassiclitellate
largest order, containing most terrestrial earthworns
23 Families, 382 Genera, over 6,000 species
Order:
Enchytraeida
potworms and ice worms
1 Family, 32 genera, 710 Species
Order:
Haplotaxida
freshwater worms
1 family, 1 genus, 20 species
Order:
Lumbriculida
Freshwater worms
2 Families, 26 Genera, 200 Species
Order:
Moniligastrida
Found in South and East Asia
1 Family, 5 Genera, 204 Species
Order:
Narapida
Aquatic interstitial worms
1 Family, 1 Genus, 1 Species
Family:
Narapidanidae
Genus: Narapidana
Species: N. serenaria
Order:
Parvidrilida
Marine interstitial worms
1 Family, 1 Genus, 9 Species
Order:
Tubificida
common aquatic worms
7 Families, 100 Genera, 1,100 Species
Order:
Haplotaxina
3 Suborders, 16 Families, 500 Genera, and approximately 10,000 species
Suborder:
Haplotaxina
1 Families, 1 Genera, 10 species
Suborder:
Moniligastrina
1 Order, 1 Family, 5 Genera, 204 Species
Suborder:
Tubficina
1 Order, 2 families, 120 Genera, over 1000 Species
Class:
Polychaeta
24 Orders, 87 Families, 1,400 Genera more than 13,000 species (2026)
marine annelids called bristle worms
Subclass:
Palpata
Family:
Protodrilidae
Family:
Polygordiikae
Subclass:
Echiura
Order:
Bonelliida
Family:
Bonelliidae
Family:
Ikedidae
Order:
Echiurida
Family:
Echiuridae
Family:
Thalassematidae
Family:
Urechidae
Subclass:
Aciculata
Family:
Levidoridae
Order:
Amphinomida
Family:
Amphinomidae
Family:
Euphrosinidae
Order:
Eunicida
Family:
Dorvilleidae
Family:
Eunicidae
Family:
Hartmaniellidae
Family:
Ichthyotomidae
Family:
Lumbrineridae
Family:
Oenonidae
Family:
Onuphidae
Subclass:
Sedentaria
Order:
Order:
Order:
Subclass:
Echiura
Order:
Capitellida
Order:
Orbiniida
Order:
Opheliida
Class:
Machaerida (EX)
Three Families: Plumulitids, Turrilepadids, Lepidocoleids.
Conservation Status
EX Extinct
EW Extinct in the Wild
CR Critically Endangered
EN Endangered
VU Vulnerable
NT Near Threatened
CD Conservation Dependent
LC Least Concern
NL Not Listed
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