life cycle of pearl oysters

1. Pinctada fucata
(Akoya pearl oyster)

2. I. INTRODUCTION
II. REPRODUCTIVE BIOLOGY
III. AGE AND GROWTH
IV. FOOD AND FEEDING HABITS
V. LIFE CYCLE

3.  About 28 species of Pearl oyster are reported so far.
 Pearl oyster are sedentary bivalves found in the ocean, at the depth of 18-
22meter and found attached to rocky ridges.
 Pinctada fucata found in Gulf of Mannar and Gulf of kutch.
 they can move with the help of foot which is tongue shaped organ capable
for contraction and elongation.

4.  There is no sexual dimorphism.
 There is a pair of gonads(Testis in male and ovary in Female) place over
the intestine.
 The gonad open by means of Gonopore located at the anterior end of the
gills.
 sperm from the testis and ova from ovary are released into the
surrounding water where fertilization takes place.
 In India spawning seasons peaks from june to september.

5. YEAR SIZE IN (mm)
The end of one year 35-45
End of second year 50-55
End of the third year 55-60
End of the fourth year 60-65
The end of fifth year 65-70
http://www.fao.org/3/contents/ad1ba50b-25b657b1-aaz9-9d16b716e90.1.1

6. • The pearl oyster is a filter feeder.
• The microalgae cell Isochrysis galbana is provide to the larvae
from the veliger.

7. LIFE CYCLE
• 45 minutes after fertilization, segmentation begins.
• Each micromere possesses a cilium by means of which it swims.
• It is attracted toward light.
AT 2 CELLED
STAGE
MICROMERE
MORULA
MACROMERE

8. Cont…
• BLASTOCOEL and BLASTOPORE are developed by the reorientation of cells.
• This is the blastula stage which is reached 5 hrs after fertilization.
• Blastula grows to gastrula 7 hrs after fertilization.
Blastoderm
Blastocoel
Chorion
Yolk
Yolk
Epiblast
Ectoderm
Chorion
Yolk

9. planktonic trochophore
larvae (free swimming)
Then develops into veliger larval stage
(swimming)

10. Cont...
• planktonic trochophore larvae (free
swimming)
•Gastrula develops a flagellum
and tuft of cilia at the apical side
and postoral tuft of cilia at the
rear end.
•Larvae swim with flagellum.
•The larvae look like letter “D”
and hence called D-shape stage
or veliger.
Bio1151b.nicerweb.com

11. • Veliger stage is reached within 20 hrs. it is 50-55micron in
size.
•In pediveliger stage eye spot
seen at the base of foot bud.
•Pediveliger (size-200um) is a
transitional stage from
swimming to crawling.
www.asnailsodyssey.com

12. • The larvae sink to the
bottom of the water
and developed into
young oyster called
“Spat”.
• Attaches to hard
substratum by means
of byssus threads
Cont….