A drop of water sample was placed on slide and coverslip was placed over it. Spirostomum was observed under foldscope.

Spirostomum is a free-living ciliate protist , belonging to the class Heterotrichea . Species of Spirostomum are found in both salt and fresh water. All are elongated, flexible and highly contractile. The body of the cell is long and worm-like.  It is mainly cylindrical but may be flattened at the tail end. A Spirostomum’s body has spiral rows of cilia. The cilia beat back and forth to move the organism with a snake-like wiggling motion. The mechanism of Spirostomum ‘s contractility was first studied by Ernst Haeckel in 1873.

Spirostomum ambiguum can contract its body length by more than 60% within a few milliseconds. According to Dr Manu Prakash, they are very special since they can contract at an incr edible speed(5ms); one of the fastest contractile cell.

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