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Pseudobiceros bedfordi (Laidlaw 1903)

Persian Carpet Flatworm

Cheryl Tan Kay Yin (2013)



Fact Sheet



Physical Description


Life History & Behaviour


Phototaxis Experiment


Feeding & Nutrition

Anatomy & Physiology

Skeletal System

Sensory System

Muscular System

Digestive System

Internal Transport System

Evolution & Systematics

Biogeographic Distribution

Conservation & Threats

References & Links

Muscular System

Polyclads are able to achieve a wide range of movements especially while swimming and gliding on surfaces. They move with a rhythmic undulating motion by contracting their highly muscularised body.
In addition, they have powerful dorso-ventral muscles to achieve full control of their body movements
(Fig 1). The muscles of the body walls exert forces against the hydrostatic skeleton providing support for movement 

Figure 1. Highly muscularised body allows P. bedfordi to twist its entire body
 with ease.

Figure 2. Longitudinal section of cuticle margin showing circular muscle fibres (A)
 and longitudinal muscle fibres (B) under high powered light microscope.

Figure 3. Dorsal surface of P. bedfordi with labelled regions 

 The internal muscle structure of the flatworm consists of outer circular and inner longitudinal muscles as well as two sets of diagonal muscles that criss-cross each other as seen under fluorescence microscopy (Fig. 3).

Figure 4.  FITC - DAPI stain of highly muscularised pharynx of P. bedfordi 
Green phalloidin stain: intertwined muscles fibres and blue DAPI stain: nuclei of muscle cells.