fish endocrine

1. ENDOCRINE SYSTEM
OF
FISHES
Ashish sahu

2. INDEX :
 ENDOCRINE GLAND.
 MAJOR ENDOCRINE GLAND.
 DETAILED STUDY OF EACH ENDOCRINE
GLAND.

3.  ENDOCRINE GLAND :
 The gland which secrete their product
HORMONE directly into the blood rather
than through a duct .
 MAJOR GLANDS OF ENDOCRINESYSTEMOF FISHES :-
o The pituitary gland or hypophysis
o Thyroid gland
o Adrenal gland
o The corpuscles of stannius
o The ultimobranchial gland
o Urohypophysis
o Pancreatic islet
o Pineal organ

5.  PITUITARY GLAND
OR
HYPOPHYSIS :
 LOCATION :-
Ventral surface of brain below
optic chiasma
 DERIVATION :-
Pituitary gland derived from two different components:-
 Adenohypophysis :
It is derived from the dorsal evagination of the ectodermal part of buccal
cavity called RATHEK’S POUCH.
 Neurohypophysis:
The neurohypophysis develop from the floor of embryonic
diencephlon.

6.  ADENOHYPOPHYSISDIVIDEDINTO THREE SUB
DIVISION:-
 Rostral pars distalis
 Proximal pars distalis
 Pars intermedia

8.  ROSTRALPARS DISTALIS OR PROADENOHYPOPHYSIS ;
 Most smallest part of the adenohypophysis.
 Chief cell of proadenohypophysis is Prolactin.
 Populated by the Acidophill cells, Cynophill,
Chromophobes.
 Acidophill cells are stained by Azocarmine (A-C) or
Orange (O-C) stain.
 Cynophill stain with Aniline blue (AB) Aldehyde
fuschin(AF) Aldehyde thionine (AT).
 Chromophobes have non granular cytoplasm, do
not take any stain.

9.  PROXIMAL PARS DISTALIS OR MESOADENOHYPOPHYSIS
 It lies in middle.
 Largest part of the hypophysis.
 Consist Acidophilic, Cynophillic and
Chromophobic cells.
 Acidophillic cells include Erythrosinophilic and
Orangeophillic cells.
 Cynophills are principal cell type of PPD.
 Chromophobes are fewer in number and
distributed among Acidophills , Cynophiles .
 Chromophobes are easily identified due to very
poor staining property.

10.  PARS INTERMEDIA
 Lies in posterioror posterioventral end of the
hypophysis.
 Consist of Acidophills, cynophiles and
chromophobes cells.
 Cyanophiles are much reduced in size and no.and
get degranulated during the post spawning phase
of reproductive cycle.
 Chromophobes are fewer in number .Amphiphillic
cells which which stain both with Aniline blue and
the Alcian blue and Orange G.

11.  NEUROHYPOPHYSIS :
 Composed of Axonal nerve fibre.
 Mostly non –myelinated .
 Originating from natural cells bodies in the
Hypothalmus.
 Many fibre terminate in the neurohypophyseal core in
close relationship to blodd vessel.
 An arrangement peculiar to Teleost.
 A SPECIAL FEATURE OF THE FISH PITUITARY IS
THE EXTENSIVE ORBORIZATION OF PARS
INTERMEDIA BY NEUROHYPOPHYSIS.
 Neurohypophysis some time in large masses termed
as “HERRING BODIES”.

13. PITUITARY
PARTS
DIVISION CELL TYPES SECRETION FUNCTION
A.Proximal pars
distalis
(i) Thyrotophs Thyrotropins
Eg. TSH
Regulates the
growth and
secretion from
thyroid.
(ii)
Gonadotrophs
Gonadotropin
Eg.FSH(follicula
r stimulating
hormone) and
LH (leutenizing
hormone)
Regulates the
secretion of
gonadal
hormone,
spermatogenes
is and
oogenesis.
1.Adenohypop
hysis
(iii)
Somatotroph
Somatotropins
Eg.GH (growth
hormone)
Increases
growth and
BMR of fish
body.

14. B.Rostral pars
intermedia
(i) Lactotroph Prolactin Regulation of
Osmoregulatio
n and
melenogenesis.
C.Pars
intermedia
------------- MSH and MCH
(melanophore
dispersing and
melenophore
contracting
hormone)
Regulates the
concentration
and dispersion
of pigments
within
melanophores.
2.Neurohypoph
ysis
Pars –nervosa ------------ Vasopressin
and Oxytocin
Regulates
Osmoregulatio
n ,salt-water
balance,
mating and egg
laying.

15.  THYROIDGLAND:
 ORIGIN:
Arises as a median evagination from the floor of Pharynx.
 LOCATION:
 In Cyclostomes: Thyroid dispersed around the ventral
aorta.
 In Elasmobranchs: Gland is located ventrally at
bifurcation of ventral aorta.
 In Bony fishes : It lies under the 1st branchial arch on
each side.
 In Teleost : found along the ventral aorta and along the
afferent Branchial artries of gills.

18.  SHAPE :
 In Cyclostomes: Thyroid is in the form of follicles.
 In Elasmobranchs and Bony fishes : Thyroid is a
compact structure.
 In Teleost: Thyroid become diffused structure as
small masses of follicles.
 In Dipnoi : Thyroid comprises a pair of
interconnected lobe.
 HORMONE OF THYROID GLAND:
Chiefly THYROXINE.

19.  CHEMISTRY OF THYROIDHORMONE :
 The Thyroid hormone is the Iodinated derivative of
THYROSINE (TYROSINE) which is an Amino acid.
 REGULATIONOF THYROXINE SECRETION FROMTHYROID:
 The production of THYROXINE hormone is under
the control of THYROTROPIN (TSH) secreted from
Adenohypophysis.
 Increase in humidity activates the Thyroid activity.

20.  ADRENAL GLAND:
The two components of adrenal
gland are:
 Cortex
 Medulla
In Cyclostomes,presumptive Adrenocortical cells occur in
scattered group on the wall of cardinal vein.
 In Elasmobranchs: The Adrenal gland does not contain
Chromaffin tissue.
 In Chondrichthys: The steroidogenic cells form internal
bodies at the caudal end of kidney and chromaffin cells lies
embedded within the tissue of both kidney near posterior
ends.

22.  FUNCTIONOF ADRENAL GLAND:
 Hormone of steroidogenic tissue are collectively
called as ADRENOCORTICOSTEROIDS which act
upon the following process:-
 Osmoregulation ,protein and carbohydrate
metabolism.
 Blood cells movement from Hematopoietic and
Lymphoid tissue.

23.  Growth,regeneration and anti-inflammatory
reaction.
 In Teleost fishes ,injection of high dises of
adrenocorticosteroid often cause effect which
disturb the Electrolyte balance.
 High doses in Anguilla anguilla increase
muscle water content while muscle sodium
concentration declines.

24.  THE CORPUSCLES OF STANNIUS
LOCATION :
The corpuscles of stannius are generally small nodular
bodies lying partly or
completely embedded on
dorsal or dorso-lateral ventro-lateral sides of kidney of
bony fishes.
EXACT LOCATION IS MEASURED FROM THE
URINOGENITAL APERTURE.
 SHAPE :
Oval and round but in Gold fish and Salmon it is flat
white structure on peritoneal surface of the kidney
 SIZE :
Corpuscles of stannius varies from 0.15-6.0 mm .

26.  NUMBER :
1 to 10 in no.
 COLOUR :
Pink or white
 ORIGIN :
Originated as outgrowth from the pronephric or the
mesonephric duct of kidney.
 NATURE :
Corpuscles of stannius are steridogenic.

27.  FUNCTION:
 PRESENCE OF RENIN ACTIVITY
Extract of corpuscles of stannius of the Eel
caused a rise blood pressure in which
resembled to that evoked by rennin.
 OSMOREGULATORY FUNCTION
REMOVAL OF CORPUSCLES OF STANNIUS
CAUSED REDUCTION IN PLASMA SODIUM AND
INCREASE IN POTTASIUM AND CALCIUM
CONCENTRATION WHICH MAY EVEN RESULT TO
DEATH.

28.  NUMBER :
1 to 10 in no.
 COLOUR :
Pink or white
 ORIGIN :
Originated as outgrowth from the pronephric or the
mesonephric duct of kidney.
 NATURE :
Corpuscles of stannius are steridogenic.

29.  THE ULTIMOBRANCHIALGLAND
 OTHER NAME :
POST BRANCHIAL BODIES OR
SUPRAPERICARDINAL BODIES OR
ULTIMOBRACHIAL BODIES
 OCCURRENCE :
It is not found in cyclostomes but reported in almost
all group of fishes.

30.  ORIGIN:
Develop embryologically from the epithelium of last or
ultimate gill pouch.
 LOCATION:
In Elasmobranchs gland is found on the left side only
between the pericardium and ventral surface of
pharynx just anterior to its junction with the
oesophagus

31. In Teleost the gland is bilateral and is located in the
tranverse septum between the abdominal cavity and
sinus venosus just ventral to the oesophagus.
 HORMONE :
Gland has been found to secrete CALCITONIN hormone
which in mammals oppose the action of
PARATHHORMONE.
 CHEMISTY OF CALCITONIN:
It is a straight chain peptide containing 32 amino acid
residue with a molecular weight of approximately 3600-
4500.

32.  FUNCTION :
 It is a source of calcium regulating hormone
–CALCITONIN,which control Hypercalcimia
and lower plasma by inhibiting bone
resorbtion in mammals.
 The concentration of CACITONIN is high in
Chimaeroids, Elasmobranch and Teleosts.

33.  UROHYPOPHYSIS :
 OTHER NAME :
Caudal Neurosecretory Organ
 OCCURRENCE :
Absence in Teleostean and identified in Agnathas.
 LOCATION:
Posterior end of caudal spinal cord ie in tail of
teleosts.

35.  STRUCTURE :
 Cells are large and have enlarge
axon of neurosecretory fibre,also called
DAHLGREN CELLS lies in grey matter of cord.

36.  UROHYPOPHYSIS HAVE MANY CHEMICAL ACTION.
 THEIR PROTEIN ANDPOLYPEPTIDE CASSIFIED
AS : -
 UROTENSINI :
Decrease blood pressure when injected to rat.
 UROTENSIN II :-
Control smooth muscles including urinary bladder
in Trout
 Increase the blood preesure and urine flow in Eels.

37. UROTENSIN III :-
 Enhance sodium uptake across the gill of Gold
fish.
 UROTENSIN IV :-
Increase water transfer and shows other
similarities to VASOPRESSIN.

38.  FUNCTION:
 Increase sodium influx in fresh water fishes.
 Diuresis and decreased Na excretion in Gold fish.
 Sodium regulation.
 Increased blood pressure in Eels.
 Increase bladder contraction in Teleost.
 Caudal fish locomotion.
 Contract smooth muscles of urinogenital tract
including sperm duct.

39.  PANCREATIC ISLET :
 Pancreas comprises both exocrine and
endocrine parts.
 Endocrinal part is represented by islet of
Langerhans.
Fish islet are fairlylarge in size ,andcomposed of three type of cells :-
 BETA CELLS (B CELLS) -which secrete
insulin.
 ALPHA CELLS (A CELLS) -which secrete
glucagon.
 D CELLS – Function is unknown.

40. PINEALORGAN:
Pineal organ arises postermiddorsal
evagination of the epithalmus.
PINEALORGANCONSIST :
 Pineal sac.
 Pineal thalmus.
 Pineal stalk.
Pineal sac considered as photoreceptive organ in
fishes .
Also consider to be an endocrine gland.
PINEALECTOMY IS LEBISTER RESULT IN
REDUCED GROWTH RATE,ABNORMALITIES IS
THE SKELETON AND STIMULATION OF

41. GLAND HORMONE NATURE FUNCTIONS
1.Hypothalamus Releasing hormone Peptides Regulates the
secretion of
hypophysis
2.Thyroid gland Thyroxine (T4),
Tridothyronin (T3)
Amino acids Reproduction,
migratory behavior,
scale and bone
formation,electrolytic
movements,metaboli
sm,and nutrients
assimilation.
3.Interrenal
(adrenal gland)
Adrenaline ,cortisol Amino acid,steroid Counteracts stress
4.Testis Testosterone, 11-
ketotestosterone
Steroids Metabolic effect,
controls secondary

42. 5.Ovary 17B-ostradiol
oestrone,
progestagens
Steroids Metabolic effect ,yolk
and egg production.
6.Pancreas Insulin , glucagon,
somatostatin
Peptides Regulation of
carbohydrate
metabolism as in
vertebrates.
7.Pineal gland Melatonin Peptides Photosensory and
secretory function.
8.Ultimobranchial
gland
Calcitonin Peptides Regulates calcium
level in blood.
9.Stannius corpuscles Hypocalcin Protein Regulates cacium
balance.

43. REFERENCE :
A TEXTBOOK OF FISH AND FISHERIES
…S. S. KHANNA & H. R. SINGH.
FISH & FISHERIES
…PANDEY & SHUKLA.
PDF OF ENDOCRINE GLAND OF FISH.
HANDBOOK OF FISHERIES AND AQUACULTURE.
E- COURSE OF ICAR .
WIKIPEDIA, ENDOCRINE SYSTEM OF FISHES.