Macrodasys andamanensis   Rao,  1993 (Gastrotrich)
Organism information awaits expert curation

Size: Maximum length 800 µm including the tail.

Maximum width of body attains 90 µm about the level of pharyngeal pores. Body transparent and dorsoventrally flattened. The anterior end is somewhat truncate without any projections on its anterior border, while the posterior end tapers into a pointed tail. Head is not demarcated from trunk and bears a pair of lateral pestle organs. Fine sensory bristles occur along the lateral corners of head and lateral margins of trunk. Ciliation forms a continuous field on ventral surface. Adhesive tubes occur in anterior, lateral and posterior series. The anterior tubes are about 10 µm long and occur in two groups of 2+3 on either side in an arc on ventral surface of head just behind the mouth. Ten pairs of lateral tubes occur beginning at the level of pharyngeal pores. Ten pairs of posterior tubes occur on lateral surface of tail and are distinctly separate from lateral tubes of the trunk. The mouth is terminal, cup-shaped and the oral cavity has a velum characteristic of the genus. The pharynx is about 220 µm long and occupies nearly 1/3rd of the total gut length. Pharyngeal pores are distinct and lie about the middle of the pharynx. The gut following the pharynx is undifferentiated into a wide stomach and tapers to the posterior end. Anus is subterminal and opens on the ventral surface.

The reproductive organs consist of a paired testis located laterally along the anterior region of the digestive tract. They are spindle-shaped starting from just behind the pharynx and the vasa deferentia terminating close to the penis. The penis is pitcher-shaped. It is located posterior to the ovary and opens anteriorly on the ventral surface. Bursa copulatrix is about 150 µm long, with conspicuous muscular and vermiform portions. The bursa opens posteriorly into a distinct antrum feminum at the tail end.

Synonym (s)

Common Name (s)
Economic Importance and Threats

Habitat:  Demersal, Sandy, Coastal


• Andaman and Nicobar Islands, Andaman Islands (Lat: 10) (Long: 93) INDIA
• Andaman and Nicobar Islands, Bomila Creek INDIA (Record: 19/03/1990) (Depth: 0.05-0.1 mts)
• Andaman and Nicobar Islands, Butler Bay INDIA (Record: 21/03/1990)
• Andaman and Nicobar Islands, Bomila Creek INDIA
• Andaman and Nicobar Islands, Little Andaman INDIA

Literature Source(s)
  • 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
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Priyalakshmi, G and Menon, NR (2008) Indian marine Gastrotricha Available at -
  • Sealifebase Available at -

Page last updated on:2010-11-22

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