Phascolosoma arcuatum   (Gray)  1828 (Marine Worm)
Organism information awaits expert curation
Class: Phascolosomatidea

Image copyrights: Guide to mangroves of Singapore

Size: Trunk 33-65 mm long; introvert 40-90 mm long

Color: The animal is pale brown to brown colored but anterior and posterior extremities are dark brown to blackish brown due to presence of aggregation of papillae.

The introvert is slender and partially retracted. Tentacles are 8-10 in number, finger-like, arranged in a horse shoe-shaped fashion and placed dorsal to mouth. Hooks are arranged in 50-60 closely set complete rows. Each hook is dark colored with sharply bent apex forming an obtuse angle. Circular and longitudinal muscle layers are grouped into bands. Retractor muscles are two pairs originating more or less at the same level but arrangement is totally reverse in this species i.e., anterior muscles arise behind and ventral to posterior ones. Spindle muscle is attached at both ends. Rectum is short and without caecum. Contractile vessel is simple and without villi. Nephridia are one-third as long as trunk and attached to body wall by two-thirds of their length.

Synonym (s)
Sipunculus arcuatus Gray 1828
Phascolosoma arcuatum Haldar 1991

Common Name (s)
Economic Importance and Threats

Habitat:  Estuarine, Muddy


• West Bengal, Jharkhali, Banamali Khal INDIA (Record: 21/09/1984)
• West Bengal, Bakkhali, Bakkhali Khal INDIA (Record: 07/03/1985, 03/04/1987)
• West Bengal, Kakdwip, Harwood Jetty INDIA (Record: 08/03/1985)
• West Bengal, Jharkhali INDIA (Record: 21/05/1985, 21/01/1987)
• West Bengal, Jharkhali, Jharkhali Khal INDIA (Record: 22/05/1985)
• West Bengal, Basanti INDIA (Record: 28/02/1986)
• Andaman and Nicobar Islands, North Andamans INDIA (Record: 1991)

Literature Source(s)
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Haldar, BP (1995) Echiura and Sipuncula Estuarine ecosystem series, Part 2: Hugli Matla Estuary ZSI, Calcutta 31-39 Available at - NIO, Goa
  • Ng, PKL and Sivasothi, N (eds.) (2001) Guide to mangroves of Singapore Available at -

Page last updated on:2009-05-26

Back to Search