Invertebrate Zoology

1. Guided by
Dr. R. K. Tamboli Sir
Submitted by
Girja Prasad Patel

2. Synopsis
 Introduction
 Definition
 Characteristics of respiratory pigment
Types of respiratory pigment
General account of respiratory pigment
Comparative account of respiratory pigment
Function of respiratory pigment
Conclusion
Reference

3. Introduction
o Blood itself not carrier of the respiratory gases but contains a respiratory
pigment which actually act as the carrier of the respiratory gases because
this pigment has a special affinity for respiratory gases.
o The respiratory pigment in its nature varies in different animals.
o Respiratory pigment differ in their chemical constitution in different group of
animals and even in the same phyla there may be several types of pigment.
o These pigment includes the cytochrome the flavoprotein and other colored
molecules of protein called “chromoprotein” which are significance in the
transport of respiratory gases and impart or definite color to the body fluid.

4. Definition –
A respiratory pigment is a molecule such as haemoglobin in
invertebrates and other vertebrates , that increases the oxygen carrying
capacity of the blood.
or
“Respiratory pigment are coloured substance present in blood
transporting the oxygen and carbon dioxide.”
or
“Respiratory pigment are circulatory pigment which mediate
transfer of respiratory gases at the extracellular and intracellular level.”

5. Characteristics of respiratory pigment :-
o They are colored pigment .
o They have special affinities for respiratory gases .
o They are distributed either in the blood or in the blood or
in the body fluid.
o They are colored proteins which contain a metallic ion.
o The combines with oxygen and carbon dioxide and play
key role in the transportation.

6. Type of respiratory pigment –
1.Haemoglobin
2.Haemocyanin
3.Chlorocruorin
4.Haemerythrin
5.Pinnaglobin
6.Echinochrome
7.Molpadin
8.Vanadiun
9. Neuroglobins
10. Cytoglobins

7. General account of respiratory pigment
HAEMOGLOBIN :-
o Haemoglobin occurs in the blood plasma of invertebrates . It is also
called erythrocrurin .
o It is a chromoprotein (conjugated protein).
o It is found in few holothurians , several crustaceans , chironomous
insect , planorbis , annelids , parasitic nematodes , flatworm etc.
oMolecular weight - 68000 kDa .
o It is red in color metallic group present is IRON.

8. CHEMICAL STRUCTURE :-
1. Haemoglobin is composed of two component namely a protein
component called Globin & a non- protein component called Haem.
2. Globin formed of four polypeptide chains of the four two are identical
and called α (alfa )chain each α chain formed of 141 amino acids . The
other two identical chains are called β chain which contain 146 amino
acids .
3. The heam is formed of iron and porphyrin . The iron is present in the
ferrous from.
4. The porphyrin is the pigment and it gives red colour to the
haemoglobin .
5. There are four haem molecules in one haemoglobin .

9. Haemoglobine :-

10. 6. When haemoglobin is treated with HCl , it is froms a brown colored
pigment called “ acid haematin”
7. When haemoglobin is treated with Glacial acitic acid it froms “ haemin
crystal ” .

11. Function :-
Haemoglobin combines with oxygen to from oxy-haemoglobin . This
combination is loose. At low oxygen pressure it leaves oxygen and for
reduced haemoglobin . At the high oxygen pressure it combines
oxygen and form oxidised haemoglobin . one haemoglobin molecule
can bind four oxygen molecule.
Haemoglobin has the ability to combine reversibilty with oxygen .
Hb + O2 HbO2
In invertebrates the function of haemoglobin is interesting
a) In some invertebrates Hb transport oxygen at atmospheric pressure
, where in other at low pressure.
b) In some invertebrates the haemoglobin store oxygen during hyoxia

12. c) The properties of haemoglobin may vary between group &
sometimes between species.
HAEMOCYANIN :-
1. Haemocyanin pigment is of wide occurrence and is a non-haem
respiratory pigment .
2. it is dispersed in the plasma and has never been found in the
corpuscles.
3. the metallic atom is copper which gives it a characteristic blue
colour
4. in addition to copper it is formed of protein also( haemocyanin =
copper + protein).
5. The molecule of haemocyanin is large and consisting of one

14. copper atom associated with a peptide chain of about 200 amino acid .
6. Its molecular weight 6650000 kDa differs in different animal .
7. Like all proteins haemocyanin absorbs Uv rays .
8. It is not able to transport equivalent volume of oxygen as the
haemoglobin.
9. Haemoglobin occur in plasma of
*Arthopoda Palaemon Limulus Daphnia
*Mollusca sepia , octopus , helix
10. In oxygenated from it is bright blue & deoxygenated from it is
colourless .

15. Haemocynin

16. CHLOROCRUORIN :-
1. It is green color respiratory pigment containing iron in ferric from.
2. It is found in plasma only .
3. The oxygen combining capacity is as great as that of haemoglobin
4. Its distribution is restricted to four familes of polychacta (Annelida).
a) Ampheretidae b) Chloraemidae c) Sabellidae d) Serpullidae
5. It is chemically closely related to haemoglobin & Cytocromes .
6. It is light green in deoxygenated form & dark green in oxygenated
from . In high concentrated from it appears light red.

17. 7. Its molecular weight 30,00,000 kDa.
8. Generally it function as oxygen carrier.
This pigment was discovered by MILNE – EDWARDS 1938 in
polychaetes later DUJARDAN & QUADRIFAGES confirmed its
occurrence in other annelids . The respiratory properties was studied
by LANKESTER and according to him the pigment exists in two
forms – one is oxidised & other is reduced from
CHLOROCRUORIN

18. HAEMERYTHRIN
1. It is voilet – pink in oxygenated form & colourless in deoxygenated
form
2. It is found in corpuscles.
3. It is formed of iron (Fe++) and protein . The iron is directly attached
to the protein and there is no prophyrin.
4. The molecular weight varies from 6,6000 kDa to 1,20,000 kDa.
5. It has been found that three atoms of iron are necessary to combine
with one molecule of oxygen
6. The oxygen carrying capacity is very low only ¼ as compared
to haemoglobin.
7. eg:- poly chaete, magelona

19. HAEMERYTHRIN

20. COMPARATIVE ACCOUNT OF RESPIRATORY PIGMENT :

21. A few other less common respiratory pigments are :
PINNAGLOBIN
Pigment name – Pinnaglobin
Metal present – Manganes (Mn)
Colour – Brown
Features – Plasma of some molluscs (pinna)
ECHIOCHROME
Pigment name – Echiochrome
Metal present – Iron (Fe)
Colour – Red
Features – Coelomic fluid of sea urchin (echinoderm)

22. MOLPADIN
Pigment name – Molpadin
Features – Pigment found in Holothurians( sea cucumber).
ECHIOCHROME

23. VANADIUM CHROMOGEN
Pigment name - Vanadium chromogen
Metal present – Vanadium (V)
Color – Unknown
Features – Blood of many tunicates (Urochordates)
NEUROGLOBINS
• Discover in 2000
•Monomeric high oxygen affinity
•Present in brain & retina of humans
•Protection from hypoxia.
CYTOGLOBINS
•Discovered in 2002
•Appareantly present in all cells,also monomeric.

24. FUNCTION OF RESPIRATORY PIGMENT :
1. Provides specific colourd of body fluid or blood.
2. Help in respiratory gases transduction and carry.
3. Gas (O2) storage .
4. PH buffers.
5. Enhancing gradients for gas diffusion .
6. Possible enzymatic function (e.g. NO)

25. CONCLUSION – From the above account we conclude the respiratory
pigment are important role in gases transduction / carries on blood of
the body fluid .
Respiratory pigment also functioned by provide a specific color different
animals respiratory pigments are different depend upon habitat and
nature.
REFERENCE :
An introduction to animal physiology : Yapp W.B.
Principal of animal physiology : Wood D.W.
A text book of General physiology : Michell P.H.
Comparative physiology of respiration : Jones J.D.