Applied Ecophysiology: An Integrative Form to Know How Culture Environment Modulates the Performance of Aquatic Species from an Energetic Point of View - Aquaculture and the Environment: A Shared Destiny - page 177

DIGESTIVE
CAPACITY

Farmed, Wild shrimp

CO 2

Na +

Lipids
Fatty acids

H + NH 4 + NH 3

O 2

Cholesterol

+

GDH

Reserves

G

Na +

CHO
--

glutarate + NH 4

GC

aa

K +

LP

CAG

CK

H 2 O
iones

++ +

alpha-
amilase

Protein

CP

C
O
M
P
E
N
S
A
T
I
O
N

A-CoA CR O 2

ßGBP

glucose

pathogens

AAF H 2 O

Peptides

I
M
M
U
N
I
T
Y

+ NH 4 CO 2

pyruvate GL

HC

OxyHC

OSMORREGULATION

HT

Free amino
acids
catabolism

M

aa

AAF

glycogen

glucose 6F

H

HC Cholesterol

aa

LP

Fatty acids

CR

Lectins

Hemocyanin Hemocytes

CK

energy + NH 4

CAG

OxyHC

proFO

GC

Protein
synthesis

AAF

DG

O 2

A-CoA

enzyms

aa

PA

glucose 6F

IMMUNE
RESPONSE

GL

HT

SN

2-M
pacifastine

pyruvate

Moult

Metabolic rate

peptides

Growth

Neurotransmitters

glycogen

C

chitin

glycogen

aa

GROWTH

pathogens

Fig. 6. Conceptual model: protein metabolism and homeostasis. The scheme includes the
main organs and systems of juvenile shrimp: digestive gland, GD , gills, G ; muscle, M ;
cuticle, C ; nervous system, SN , hematopoietic tissue, HT and hemolymph, H . Genetic
variability is the basis of the model as it affects the flow of energy from food chemistry to
physiological processes. Litopenaeus vannamei juveniles grown in closed loop and sorted by
size (F7, F25) have a limited capacity to respond to carbohydrate diets (CHO) demonstrating
high protein dependence in their metabolism. The degradation of proteins generates
peptides and amino acids ( aa ) that are oxidized or used to synthesize glycogen . The aa can
also be used for the synthesis of digestive and metabolic enzymes, and immune proteins
(such as prophenoloxidase, ProPO , lectins, L , lipoprotein recognition, BGBP , clothing
protein, CP , antimicrobial peptides, AP ; of regulation of the immune response; pacifastine
and α2-macroglobulin, and hemocyanin, H , which seems to play a role in the immune
response of shrimp, in addition to functioning as a storage protein in the hemolymph.
Amino acids can also be transported to the hemolymph to form the pool of free amino acids
( FAA ), which can be used to generate muscle tissue.

direction, for example in conditions of nutritional stress, catabolism of glucogenic amino
acids is the basis for the gluconeogenic route for CHO can be used as energy substrate. The
cycle of fatty acids ( CAG ) is connected to the glycolytic pathway through A-CoA , a high
concentration of ATP or NADH promotes the synthesis of fatty acids from the A-CoA. The
ß-oxidation of lipids from food or reserves represents the reverse direction to generate
metabolic energy.

Regulation of osmotic pressure is mainly associated with the Na-K ATPase, ion exchange,
the catabolism of aa and the activity of glutamate dehydrogenase ( GDH ), which controls