Hesionides andamanensis     (Marine Worm)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Annelida
Class: Polychaeta
Order:Phyllodocida
Family:Hesionidae

Description
Size: Total body length 0.8-1.0 mm

Small, active and colorless worms, with elongate and compact body light-green in color. Body with 12 to 16 setigers. Maximum width without parapodia varies between 50 to 70 µm. Body tapers slightly posteriorly. Anterior head end with 11 appendages characteristic of the genus. Dorsal and ventral tentacles are directed forwards and reach about 40 µm in length. Median tentacle at the level of second tentacular cirri attains 55 to 60 µm long and projects slightly beyond the anterior extremity of head. Three pairs of tentacular cirri are laterally directed with progressive increase in length from anterior to posterior end and reach 50 to 80 µm. Tentacles and tentacular cirri with broad bases and tapering tips, but lack distinct knot-shaped swellings.
Setigerous segments are distinct, wider than long and slightly narrowed towards caudal region. Biramous parapodia stand erect slightly above the stem. Notopodia with dorsal cirri 20-25 µm long, lacking knot-shaped swellings. Two simple notosetae of varying length occur with bent subdistal part, the longer one with 3 saw-shaped teeth and the shorter one with 2 similar teeth. Notopodia with one fine tapering aciculum. Neuropodia look rectangular from above with slightly bent short cirri. Compound neurosetae 4-5 in number with slightly curved unidentate blades of variable length, one of them being always the longest. One fine tapering aciculum present.
Pygidium with two distinctly separated rectangular anal lamellae, with circular openings of adhesive glands at the end. Two anal cirri are long and thread-like, swollen at the base. Pharynx with two folds and 8 tapering papillae at the oral end.

Sexes are separate. Females with oocytes extending from fourth setiger back to the last segments. Each oocyte measures about 30 µm in maximum diameter. Males with long, thread-like sperms. Paired vesiculae occur in the third setigerous segment. Male openings occur close to the dorsal median tentacle.


Synonym (s)

Common Name (s)
Economic Importance and Threats

Ecology
Habitat:  Sandy, Coastal

Biogeography


• Andaman and Nicobar Islands, Butler Bay INDIA (Record: 21/03/1990) (Depth: 0.05-0.1 mts)
• Andaman and Nicobar Islands, Bomila Creek INDIA (Record: 19/03/1990)
• Andaman and Nicobar Islands, Dugong Creek INDIA (Record: 24/03/1990)

Literature Source(s)
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org
  • Rao, GC (1993) Littoral meiofauna of Little Andaman Records of the Zoological Survey of India. Occasional paper no. 155 ZSI, Calcutta 120 pp Available at - NIO, Goa


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