This document discusses breeding methods for Asian clams. It describes that Asian clams are hermaphroditic and release 320-387 offspring daily from July to September. Two main breeding methods are discussed: heat shock breeding which involves regulating water temperature, and scraping gonads which involves dissecting clams and smashing gonad tissue in distilled water. Both methods aim to induce spawning, and any resulting larvae can be observed under a microscope within 72 hours.

1. Asian clam breeding
S. Prudvi
M.Sc animal biotechnology,
SVU college of sciences,
Tirupati.

2. Introduction
Asian clamp are unisexual both male and female are present
in the same organism
Colour of the clam will varies. Based upon the water
fluctuation.
Black clam –lake (stagnant water)
Green clam-river (flowing water)
The shape of the clam also the temperature varies helps in
the sperm or ovum production
Temperature increase –male is dominant-releases the
spermatozoa
Temperature decreases-female is dominant-releases the ovum
The clam consists of two hard shells &to this shell the gills are
attached.
In the between to these gills the body systemic organization
was present &also contains a tongue/foot
The tongue/foot helps in locomotion& also in grasping the
food
The gills helps in breathing& where as the other parts
contains the along with other organizing systems of body.

3. Identification
The species has a typical oval-triangular clam shape, with a
dorsal “beak” or umbo at the peak of the shell.
The outside of the shell (periostracum) is olive, or yellowish
to black-brown in color, with 1-3 brown/purple colored radial
bands (particularly in juveniles) and white erosion rings near
the umbo.
The inside layer of the shell, the nacre (or “mother of pearl
layer) is typically white-bluish white in color.

Inside each shell half (or valve), there are also 1-2 pair of
small, elongated and , finely serrated lateral “teeth” that
extend on either side from the umbo part way down on the
inside edge of each valve.
Also, the interior of each valve, immediately under the umbo,
there are 3 cardinal “teeth”

4. The clam most closely resembles
native sphaerid (fingernail) clams,
however, sphaerid clams are smaller
(6-14 mm), more oval in shape, cream
colored, have fine growth rings, lack
serrations on the lateral teeth and are
found completely buried in the
sediment.
These relatives of Corbicula are also
found in slow flowing waters with
poorer water quality.

6. Reproduction
Mature Asian Clams are hermaphroditic and it is believed that
they occasionally self fertilize.
The young are incubated within the safety of the parent’s shell,
and are released 4-5 days later. The young
microscopic pedivelligers travel along the substrate to new
locations and attach to any available suitable
substrate with byssus fibers. Young that are hatched in the
spring usually attain sexual maturity by the
fall, and may live for up to seven years. Asian Clams typically
spawn between July and September.
· Asian Clams can release over 320-387 offspring daily,
depending on the conditions.
· Water temperature extremes (above 370 C and below 10C) can
inhibit spawning.

8. Management Methods
The breeding is mainly two types
1 heat shock
2 scrapping gonad
Heat shock method
temperature regulation
•Two sample of mini aquarium along with clams are
taken
•A healer with a temp of generally 24c-26c was
measured.
•And introduced into the aquarium containing water
& clam sample
•And left for four hrs
•Then transferred to the normal aquarium for
incubation then result can be observed

9. Scrapping gonad.
•Dissection of clam are done
•And only the part containing distilled &
gonads are taken as sample
•The gills shells, tongue/foot was not taken
•By pouring distilled water the sample was
smashed
•The liquid from this smashed sample was
taken & introduced into the group of samples
of clam
•Then transferred in to the normal aquarium
for incubation result can be observed from
48hours to 72 hours

10. Result
After the breeding process for 72 hours we
can observe the Asian clam larvae under the
microscope as given images below as report.