complete description about the cardio vascular system of crustaceans especially the details about the shrimp circulatory system. which includes evolutionary adaptation and changes, comparison between other invertebrates and vertebrates, diseases occuring in circulatory system of shrimp and their histopathology in comparison with normal histology.

1. CIRCULATORY SYSTEM
OF CRUSTACEA
Shyam K U
Kirti Komal
MFSc (AAHM) students

2. Introduction to Crustacea
• Belongs to Phylum Arthropoda
• Joint segmented body with paired appendages shows
metamerism
• Body is covered with chitinous exoskeleton which is
continuously shed through a physiological process
called Ecdysis
• Triploblastic, Eucoelomate, Symmetric
• Open circulatory system, Ventral nervous system and
respiration through gills

3. What is circulatory system ?
• It is a fluid-filled network of tubes (or vessels) through
which materials move between the environment and the
cells of a multicellular animal.
• It connects all parts of an organism in a way that allows
individual cells to thrive as well as for organisms to
function as a unit
• Works on the basis of pressure gradient and Law of
Bulk flow

4. • 3 components – A pump or propulsive structure, system
of channels or tubes & circulating fluid
• It can be open or closed circulatory
• Open circulatory system means the fluid is circulated
throughout the coelom via the action of the body wall
musculature and animal movements.
• Closed circulatory system is more structured and
controlled and the blood of a closed system always
flows inside vessels

5. Closed C. S.
Open C. S.

7. Role of Evolution
Porifera
Cnidaria
Playthelminthes
Nematoda
Arthropoda
Mollusca (except squid and
octopuses)
Echinodermata
Chordata (tunicates)
Annelida
Mollusca (squid and
octopuses)
Chordata (cephalochordates
and vertebrates)

8. Crustacea

9. • From invertebrate to vertebrate, the Heart has
undergone progressive evolutionary changes
• The invertebrate has elongate, tubular, non-chambered
heart with slit like opening called ostia
• For example, Branchiopoda has elongate, tubular
heart with 14-18 pairs of segmental ostia
• Cladoceran heart is globular with only one pair of
ostia

10. • A definitive heart is lacking in all cirripeds
• In lower vertebrates like fishes, the evolution of true
chambered pump heart – A tubular venous heart with
series of 4 chambers
• Higher vertebrates possess well developed
chambered-pump heart with no mixing of pure and
impure blood
• The evolutionary changes brought the circulation in a
pure & impure difference from a mixed state

11. • Gradually the arterial, venous and capillary systems
evolved in a sequential order – made the circulatory
system likes in Human beings
• Despite the structural diversity, C. S shares many
features in common
 Transport O2 and nutrients actively to the
metabolizing tissues.
 Remove CO2 and other waste products
 Helps to coordinate the physiological processes
 Assist in the defense mechanism of body

12. Circulatory System of Crustacea
• Open circulatory system
• Haemolymph flows throughout the haemocoelic cavity
• Circulation of blood –body movements, muscular and
gut contractions, pumping action of heart
• Not all crustaceans are provided with heart
• Heart is a simple, single chambered organ

13. • Lying dorsally above the gut and enclosed in a
pericardial sinus
• Accessory heart may be developed in one or more
blood vessels
• In Malacostraca, referred as a cor frontale, enlargement
of the blood vessel
• Veins are lacking in all crustaceans
• Arterial system is well developed

14. • Venous pathway are through a series of sinuses that
return the blood from the tissues and respiratory surfaces
to the pericardial sinus
• The principal component of the system is anterior aorta
• Which leads from the heart anteriorly towards the
cephalic region
• To this posterior, lateral and occasionally ventral arteries
may be added

15. • Retrograde blood flow is prevented in the arteries by
cardioarterial and arterial valves
• In the venous sinus by venous valves
• The musculature of the heart may vary from simple
pattern of fibers to a thick layer formed by crossing
muscle strands.
• Pumping action of accessory heart – by the contraction
of outer tangential muscle or internal muscles of the
blood vessel

16. Circulatory System of Shrimp
Heart Ostia Arteries
Haemal
Sinus
Cor
frontale

17. Heart & Ostia
• Bulbous dorsal heart, neurogenic
• Located posterior region of the cephalothorax, above
the stomach , at Picard cavity
• Heart is surrounded by a pericardial sac & receives
blood through a series of ostia
• The muscular ventricle is housed inside a prime
chamber, the pericardial sinus
• No. of ostia of the heart may vary depending on the
species

18. • 3 pairs is the most commonly reported number
• Location of the ostia:- Dorsal, Ventral and Lateral

19. Arterial System
• 5 arterial systems ( 7 individual vessels ) originates
from the heart – splitting into smaller arteries –
finally into capillary - like vessels
• Anterior aorta – gives haemolymph to the anterior
part of the cephalothorax - eyes, supraesophageal
ganglion
• vestigial in Penaeids
• Dorsal or Posterior aorta – principal Haemolymph
supply to the abdomen

20. • Gives off segmental arteries in each somite to supply
the gut, posterior parts of the mid-gut gland, abdominal
muscles, pleopods, uropods and telson
• Descending artery – connects the heart and the ventral
abdominal artery
• Anterior lateral arteries – supply haemolymph to the
cephalic appendages, walls of the foregut,
musculature, antennal gland and carapace
• Hepatic artery – supply haemolymph to the mid-gut
glands (hepatopancreas)

21. • Lateral cephalic artery – supply haemolymph to the
other organs including gills
• Sternal artery – bulblike swelling immediate posterior
to the heart
• After passing the ventral nerve cord, at 3rd and 4th
pleopod ganglia, divided into two
• Anterior ventral thoracic and Posterior ventral
abdominal arteries

22. • Anterior ventral thoracic artery – to mouth parts and
1st 3 pairs of pereopods
• Ventral abdominal artery – well developed in
Macrobrachium but reduced in Penaeidae
• distribute haemolymph to the 4th and 5th pereopods,
nerve cord posteriorly, and to portion of the ventral
part of the abdomen

24. Shrimp Arterial System

25. Haemal Sinuses
• They are the tissue spaces or body cavities filled with
haemolymph in the body
• Characteristic feature of the open circulatory system
• Flooded with venous blood, serves as the passageways
of venous blood return to the heart
• Equipped with venous valves to prevent the retrograde
flow of the blood to the heart during systole
• eg: Ventral Venous Sinus

26. Cor frontale
• The anterior aorta may be equipped with an enlargement
termed as Cor frontale
• 1st described by Baumann (1917) & Studied by
Steinacker in 1978
• Function as an ‘auxiliary heart’
• Pumping action by contraction of outer tangential
muscles or internal muscles of the blood vessel

27. Haemolymph
• Circulating fluid - Copper (Cu) containing
Haemocyanin as the pigment – slightly bluish in colour
• Combines the function of blood and lymph – Haema +
Lymph
• Flow through the blood vessels, also directly contact with
the tissues
• Consists of liquid part and solid part as formed
haemocytes – 3 types – Granulocytes, Semi-granulocytes
and Agranulocytes

28. Physiology of Circulation
• Heart is suspended within the cavity via a series of
ligaments
• The neurons of the cardiac ganglion, located on the
surface of the heart and among the cardiomyocytes –
primary rhythmic generator
• Neurons send signal to close the ostia – initiate the heart
beat
• Cardiomyocytes contracts – decrease the volume of the
heart chamber – exert pressure

29. • Increasing pressure causes blood squirt out of the heart
• Channeled to various body regions by arteries and
capillaries
• Do not possess smooth muscle in the artery walls
• Contraction and relaxation of a pair of muscular
cardioarterial valves at the base of the each arterial
system controls haemolymph flow

30. • After passing through the tissues, the haemolymph
drains into a sinus located along ventral side of the
body
• This sinus leads to the gills, where the haemolymph is
reoxygenated prior to its return to the heart
• Heart is surrounded by a pericardial sac that is
penetrated by passageways where venous blood return
to the pericardial chamber

31. • Blood enters the heart via pericardial sinus through one
to many pairs of valved ostia
• Blood leaving the heart may flow directly into the
sinuses and lacunae of the haemocoel
• In Penaeus sp – 2 pairs are dorsal and one is in lateral
• In some Crayfish and Lobsters – 1 dorsal, 1 ventral and
1 lateral

32. • During diastole – the ligaments spring back, pulling
apart the walls of the heart
• This elastic recoil increases the volume of the heart,
reducing the internal pressure
• At this point, the valves of the ostia opens, and
decrease in pressure sucks fluid into the heart via
ostia
• Then systole will start, cardiac cycle continues…..

33. Systole
Diastole

34. • Heart act as both suction and pressure pump
• Heart rate and stroke volume can be controlled
independently via nervous input from the cardiac
ganglion and CNS
• Or by direct actions of neurohormones on the cardiac
muscle
• A variety of neurohormones have been shown to
control regional haemolymph flow
Some Facts….

35. • Suggests that the complex network of lacunae
morphology similar to capillaries
• Only difference is lacunae lacks endothelial lining
• Major sinuses are bordered by fibrous connective tissue
and the lacunae by basal laminae
• Some reviews exemplifies that the decapod crustaceans
have ‘incompletely closed circulatory system’

36. Histology of shrimp heart
Overall longitudinal view of heart & surrounding tissues.

37. • The heart is located ventral to the dorsal cephalothoracic
cuticle (Cut) and associated cuticular epidermis(Cep)
and dorso-posterior to the hepatopancreas (Hep).
• It is suspended within the pericardium (Per) , or
pericardial chamber, at various points by suspensory
ligament (Lig).
• Surrounding the heart is the protective epicardium (Epi),
composed of specialised spongy connective tissue
• Heart is composed of myocardial cells (Myo) arranged
into bands, organized into bundles as the muscularis
frontalis (Msf).

38. Overall cross-section of heart and surrounding tissues.

39. One of six dorsal ostia (Ost) , which penetrate the epicardium
(Epi) and myocardium(Myo). The ostia allow foe haemolymph
to be drawn from the pericardium into the heart lumen sub-
chambers (Lum).

40. Enlarged view of dorsal ostium (Ost). The epicardium
and the myocardium both end at the distal tips of the
ostial flaps. Hemolymph enters the heart from the
pericardium via the ostium.

41. Posterior aorta (Aop) and its associated valve (Val) as it leaves the
heart. The posterior aorta exits the heart from a ventero-lateral
posterior aspect. Immediately ventral to the distal portion of solitary
valve flap is the proximal origin of sternal artery (Ars).

42. Enlarged view of posterior aorta and proximal valve.
Indicated by the arrow is the direction of valve travel with the
passage of haemolymph.
The posterior aorta is lined by a thin endothelial layer (End).
Intimately associated with the valve is the cardiac ganglion cell and
nucleus (Nuc)

43. Single branch of anterior aorta (Aoa) and associated valve.
Bold arrows indicate the motion of the flaps , with the movement
of haemolymph.

44. • Unlike the valve of posterior aorta, this valve, has a
dorsal and ventral flap.
• Flow in the opposite direction would cause these flaps to
close shut not allowing the haemolymph to re-enter the
heart.
• The two branches of anterior aorta exit the heart from a
dorso-anterior aspect.
• Heart myocardium and epicardium is also visible.

45. Enlarged view of heart exterior surface and the epicardium
(Epi). Majority of muscle bands (Msl) sectioned longitudinally.
Myocardial cell nuclei (Nuc) and associated satellite cells
nuclei (Sat) visible. Nuclei of epicardial cell (Epn) indicated
with a large cytoplasm.

46. Local innervation of heart provided by a nerve trunk (Nrv) and
anastomosing branches, and 9 cardiac ganglia cells (Gan).
Ganglia appears to be concentrated near the dorsal surface of
heart. Reserve cells (Res).

47. Diseases affecting Circulatory system
• White spot syndrome (WSSV)
• Penaeid acute viremia of Kuruma shrimp (PAV)
• Infectious myonecrotic viral disease (IMNV)
• IHHNVD
• Microsporidian infection.
• All of them not exhibiting a particular signs or tissue
predilection for the cardiac tissues.

48. Histopathology
• Necrosis : focal/multifocal
• Oedema formation

49. • Pyknotic nuclei
• The deeply eosinophilic necrotic cells have lost
their nuclei.

50. • Presence of cysts:
• Manifestation of microsporidian infection in heart
myofibres.

51. Reference
• Carl L. Reiber and Iain J. McGaw (2009). A Review of the open
and closed circulatory systems: A new terminology for complex
invertebrate circulatory systems in light of current findings., Inter.
J. Zoology
• Bruce E. Felgenhauer (1992). Internal Anatomy of the Decapoda:
An Overview., JVMicroscopic Anatomy of Invertebrates, Volume
10: Decapod Crustacea, pages 45-75
• C. D. Moyes & P. M Schulte (2007). Principles of Animal
physiology: Circulatory systems 2nd edn, 9 &10;374-426
• Brian R. McMahon (2001). Control of cardiovascular function
and its evolution in Crustacea., The Journal of Experimental
Biology 204, 923–932
• Thomas A. Bell and Donald V Lightner (1988). A Handbook of
Normal Penaeid Shrimp Histology