- Excretion in Mollusca:-
- Organ of Bojanus:-
- Brown, spongy, thick-walled, glandular part or kidney proper &
- Small, thin-walled, non-glandular, ciliated urinary bladder.
- Keber’s organ:-
Molluscan
excretion takes place by the kidney (organ of Bojanus) & Keber’s organ.
The kidney in bivalvian molluscs is known as organ of Bojanus.
Excretion in
Unio sp. or Lamellidens sp. takes place by – 1. A pair of organ of Bojanus
& 2. Keber’s organ or pericardial gland.
Kidneys of bivalves are called organ of Bojanus after the name of the
discoverer.
Location:-
These are situated one on each side of the body below the pericardium.
Structure:-
Each kidney or organ of Bojanus is a long, dark tube, open at both
ends. It consists of 2 parts -
The glandular part of the kidney opens into the pericardium by renopericardial aperture.
The urinary bladder opens to the suprabranchial chamber of the mantle
cavity, by a minute opening,
called renal aperture/ nephridiopore.
Physiology of
excretion:-
Urine originates as an ultrafiltrate from the heart into the
pericardium.
The glandular part of the kidney extracts guanin & other
nitrogenous waste products of metabolism from the coelomic pericardial fluid.
Here resorption of the minerals & water takes place.
The ciliated epithelial lining
of the urinary bladder produces an outgoing current which takes away excretory
product like NH3 & urea etc. to the outside through renal aperture,
suprabranchial chamber & exhalant siphon respectively .
It is also known as pericardial gland.
It is a large, reddish brown, glandular mass
situated in front of the pericardium, & responsible for the
excretion of nitrogenous waste products. The excretory products are discharged
into the pericardium from where these are collected by the organ of Bojanus to
be discharged to the outside.
Which nitrogenous waste is state by owners organ ???
ReplyDeleteUrea
DeleteGud
ReplyDelete