HIGH-RESOLUTION FOLDSCOPY OF A BIOLOGICAL MICROMACHINE: VORTICELLA

Dec 28, 2018 • 10:22 AM UTC

Unknown Location

140x Magnification

Microorganisms

Gurdeep Rastogi

Learn about the author...

51posts

8comments

1locations

Our foldscope team was
onboard for sampling from Chilika Lagoon along with 6 students and PI of
foldscope project from Department of Zoology, D.N. Government College Itanagar,
Arunachal Pradesh on 27th Dec 2018. It was a fabulous bright sunny day and we were
sure that in our pursuit for capturing the live biological machines in action
Chilika and foldscope will not disappoint us. We took a halt at Kalijai, a
small island located inside the Chilika Lagoon famous for Goddess Kalijai. We
observed dense growth of red and green algae attached to side walls of floating
jetty of the island. Students collected some of these algae and on-boat
foldscopy unveiled the functioning of a small biological machine: The
Vorticella in their natural settings. Foldscopy not only provided a
high-resolution real-time imaging of Vorticella that was busy in sweeping food
through the movement of its cilia but also other biological communties such as Navicula (a phytoplankton), fish egg
larvae, protozoa, rotifer and many more creatures that were busy in running
here and there.

Red algae attached to the Floating jetty near Kalijai Island

Collected algae sample from the jetty to be observed under foldscope.

Looking for organism to mount on slide.

Slide preparation

Vorticella under foldscope.

Movement of Vorticella captured under Foldscope. Seeing and capturing the
functioning of Vorticella, a biological micromachine was a very exciting moment
for all of us particularly to our visiting NE partners who were basically B.Sc.
Zoology students studied well about these protists but never got a chance to
see them in action. Vorticella is a protist (protozoan) and belonging to the
Phylum Ciliophora. It has a peculiar inverted bell shaped structure often attached by a long highly contractile stalk to some
submerged objects like weeds, animals and stones, algal filaments etc. Adults
also swim freely if their stalks are cut, or if they have to detach themselves
from the substrate due to unfavourable conditions. Vorticella are found in freshwater ponds,
lakes, rivers and streams. Due to the bell-shaped body it is often called
bell-animalcule. The bell-shaped body of Vorticella is attached to weeds or stones
by a long, thin, un-branched and highly contractile stalk. Vorticella
exhibits high degree of contractility and irritability; it is extremely
sensitive to any mechanical stimulus and also responds to external stimuli.
When irritated, it’s all activities cease at once; the stalk is retracted and
becomes coiled into closed spiral to reduce its size, then the disc is
withdrawn and covered over by peristomial lip. There are oral cilia specialized for making water currents that beat to
bring food closer to its mouth.