The document discusses the hypophysation technique for inducing breeding in fish. It involves removing the pituitary gland from donor fish, preparing an extract from the gland, and injecting the extract into recipient fish to induce spawning. The technique was first developed commercially in Brazil and was attempted in India in 1937 to induce breeding in Mrigal fish. The document provides details on selecting donor fish, removing and storing pituitary glands, preparing the extract, injecting recipients, and releasing induced donor fish.

1. Submitted to,
Prof .H.V.Parmar
College of
fisheries
veraval
Submitted by ,
Ketul Patel
Roll no:-26
Reg.no:-j3-00326-2014

2.  The technique of induction of breeding by
administration of pituitary extract is called
hypophysation technique.
 Brazil was the first country to develop
hypophysation technique on commercial
scale.
 In India the first attempt to induce C.mrigla
to spawn by injection of mammalian pituitry
extract was done by khan in 1937.

3.  Removal of Pituitary Gland from Donor Fish .
 Storage of Pituitary Glands.
 Preparing and Injecting the Pituitary Extract.
 Release of Induced Donor Fish.

4.  Select sexually mature and unspent donor
fish (male or female) as pituitary donors.
 Anaesthetise the donor fish using a suitable
anesthetic until deeply sedated and
sacrifice.

5.  Wash and remove the fatty tissue away,
hold the hind margin of the brain with a
pair of fine tweezers, gently lift and fold the
brain back on to itself (posterior to anterior
direction) to expose the pituitary gland
lying directly under the brain

7.  Wash the surrounding tissue debris by
rinsing with clean water before carefully
removing the pituitary gland.

8.  Pituitary glands that are not required for
injection immediately can be stored for as
long as 6 months using reagent grade
acetone.
 For long-term storage first place the
pituitary glands in airtight vials containing
acetone for 24 hours and then replace the
acetone with a fresh aliquot.
 These vials can be stored at room
temperature or refrigerated until required
(up to 6 months).

9.  Just prior to induction of donor fish, take
out the stored pituitary glands from their
respective vials and place on tissue paper to
air dry.
 If working with fresh glands use them
directly for extraction.
 Weigh the required amount of pituitary
gland (based on the weight of the recipient
fish: 4-6 or 10-16mg/kg body weight for
male or female recipient respectively)

10.  Carefully transfer the weighed glands to a
microfung tube.
 Add sterile double distilled water to each
vial and grind the tissue finely using a
micro-pestle.

12.  grinding more distilled water was
added to achieve a concentration of
approximately 40 mg/ml of pituitary
extract and mixed thoroughly.
 The pituitary extract was then
centrifuged at approximately 1-2K
RPM for about a minute to separate
the tissue debris from the extract.

14.  Suitable sites with water plumes flowing
through the holding pen and traps were
selected for the trial.
 Holding pens were placed directly behind
fish traps, such that pheromone (attractant)
released by the donor fish would be carried
through the traps and into the lake.
 Suitable barriers were installed to avoid
inadvertent access of attracted fish to the
donor fish.

15.  Fish seed is guaranteed all year round.
 Increase the survival rate of fry
 Improve quality by crossing two different
species.

16.  Loss the donor
 Whole process is laboratory and highly
technical.
 Very expensive.