filter feeding of molluscs

1. FILTER FEEDING
OF MOLLUSCS
Submitted by
A.V.Swathilakshmi
I Msc Zoology

2. UNIO

3. FOOD
O Unio is a planktonic feeder
O Its food consists of diatoms, protozoa,
other micro organisms and organic
detritus brought in by the circulating water
current

4. FEEDING
O Unio displays filter feeding that involves
straining food from large quantities of
water.
O The beating of lateral cilia of the gill
filaments draws water into the infra-
branchial chamber of the mantle cavity
through the inhalent siphon.

5. O The beating of lateral cilia of the gill
filaments draws water into the infra-
branchial chamber of the mantle cavity
through the incurrent siphon.
O The water current enters the gills through
the ostia and egresses to outside through
the excurrent siphon via the
superbranchial chamber of the mantle
cavity

6. O The incoming water contains millions of
microorganisms ,constitute the animal
food.
O The beating of the latero frontal cilia of the
gill filaments towards the outer surface of
the lamallae throws the fine food particles
onto the lamellar surfaces.

7. O The heavier sand particles are conveyed
from the gill surfaces to the edge of the
laminae, which touch the mantle.
O From here these are dropped into the
bottom mantle cavity.
O The lamellar surfaces secrete a mucous
sheet to trap the food particles.

8. O The frontal cilia of the gill filaments beat
downwards towards the food
groove,moving the mucous sheet
downwards.
O The mucus from both side of each gill
lamina moves into the food groove.
O Here,ciliary beating moves the food
towards the mouth.

9.  while reaching in between the labial palps
further sorting of food particles takes place.
 This is achieved by the overlapping folds
on the inner surface of inner surface of the
labial palps.
 In between there will be ciliary tracts beats
outside of the gutter which helps to
separate the heavier particles.
 Another set of the ciliary particles which
helps to move fine particles to the mouth

10. O Through this food passes into the
oesophagus and stomach.
O The heavier particles are accumulated on
the labial palps fling to sweep them to the
mantle cavity
O A sudden thrust of the water outward
through the incurrent siphon carries the
rejected food particles and sediment out of
the mantle cavity.