Annelids - Segmented Worms

 

Phylum: Annelida  (Lamarck, 1802)

General Information

  • Latin: Annulus = Little Ring
  • Also known as ringed worms or segmented worms
  • Includes earthworms, leeches, marine worms
  • Approximately 15,000 + species, ranging in size from microscopic (less than 1mm) to the Australian giant Gippsland earthworm (3m long)
  • 2/3 of annelids are marine species

Distribution

  • Found worldwide

Habitat

  • Live in a diversity of freshwater, brackish, marine, and terrestrial habitats
  • From the deepest marine sediments to soils in your backyard

Distinguishing Features

  • The Annelids are coelomate and triploblastic.
  • Bilaterally symmetrical
  • They exhibit organ system level organization. (when two or more organs work together for a specific function).
  • Their body is segmented.
  • Do have parapodia for locomotion
  • Invertebrate
  • Long cylindrical shaped bodies made up of many similar segments
  • Has Chaetae (setae) (bristles for anchorage, movement and sometimes defence)
  • No hard skeleton exoskeleton (unlike Arthropoda)
  • No antennae, no appendages (legs)
  • No obvious head end

Annelids are divided into 3 groups (2 of which are terrestrial)

  1. Class: Clitellata (having a Clitellum) - Worms and Leeches
    • Subclass:     Hirudinidea        - Leeches
    • Subclass:     Oligochaeta       - Worms
  2. Class: Polychaeta (pol-ee-keets)     - Marine worms
    • Subclass:     Echiura             - Spoon Worms
    • Subclass:     Errantia             - Free Swimming Worms
    • Subclass:     Sedentaria        - Sedentary Worms   
  3. Order: Sipuncula                             - Peanut worms

 

 

Class:   Clitellata          Worms and Leeches

  Subclass:   Hirudinea          Leeches

    Infraclass:   Euhirudinea          True Leeches

      Order:   Rhynchobdellida          Jawless Leeches

        Family:   Glossiphoniidae          Freshwater Jawless Leeches

 

 

Glossiphonia sp. _ Freshwater Leech - VICTORIAN SPECIES

Picture taken at Sweetwater Creek, Frankston on 11.09.2022

 

 

  Subclass:   Oligochaeta          Worms

   Order:   Crassiclitellata          Earthworms

    Family:   Lumbricidae          Typical Earthworms      

 

Eisenia sp. _ Freshwater Red Worm - VICTORIAN SPECIES                      Oligochaeta sp. _ Freshwater Worm - VICTORIAN SPECIES

         

Picture taken at Sweetwater Creek, Frankston on 11.09.2022                                         Picture taken at Sweetwater Creek, Frankston on 11.09.2022

 

 

Class:   Polychaeta (pol-ee-keets)          Marine worms

  Subclass:   Echiura          Spoon Worms

 

Ikeda taenioides_Sand Worm - VICTORIAN SPECIES    

Frankston Pier_Photo by Paul Sorensen

 

  Subclass: Errantia - Free Swimming Worms

 

Eunicidae sp._Eunicidae - VICTORIAN SPECIES    

Blairgowrie Pier_Photo by Paul Sorensen

 

Aphrodita australis_Southern Sea Mouse - VICTORIAN SPECIES

Picture taken at Blairgowrie Pier on 04.10.2023

 

Glycera sp._Annelid - VICTORIAN SPECIES                                            Hesionidae sp._Ragworm - VICTORIAN SPECIES

    

Deakin University_Photo by Paul Sorensen                                                                Blairgowrie Pier_Photo by Paul Sorensen

 

  Subclass: Errantia - Free Swimming Worms

 

Sabella spallanzanii_Fan Worm - VICTORIAN SPECIES

Blairgowrie Pier_Photo by Paul Sorensen

 

Order: Sipuncula - Peanut Worms

Phascolosoma noduliferum_Peanut Worm

Deakin University_Photo by Paul Sorensen

 

OTHER SPECIES

 

Anelassorhynchus porcellus _ Spoonworm

Picture taken Edithbugh, South Australia on 10.07.2025

 

 

 

 

 

 

Sipunculus sp. _  Peanut Worm

     

Picture taken Amed, Indonesia on 10.07.2025

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