Penaeus indicus is a marine prawn found in tropical and temperate seas. Its segmented body consists of two main regions - the cephalothorax, formed from the fusion of thirteen segments including five cephalic and eight thoracic, and the abdomen. The prawn's elongated body tapers slightly at the rear and is covered by a segmented exoskeleton made of chitin and protein. This exoskeleton protects the internal organs, provides attachment points for muscles, and includes infoldings called apodemes that further strengthen and support the body. The prawn has nineteen pairs of appendages including five pairs of cephalic, eight pairs of thoracic, and six
2. Penaeus indicus
Penaeus is the marine prawn,widely distributed
in tropical and temparate seas.
The segmented body of prawn has two
regions,cephalothorax and abdomen.
Cephalothorax is formed by the fusion of thirteen
segments,namely five cephalic and eight thoracic.
Abdominal region has segments and a terminal
conical process,called telson.
3.
4. The body of prawn is
elongated,hemispherical and slightly tapering
at the posterior end.
The fresh specimen is slightly bluish in colour.
The whole body of prawn is covered by a
segmented cuticular exoskeleton,secreated by
the underlying epidermis.
It is formed of chitin and protein.
5. Exoskeleton protects the body and provides
provisions for the attachment of muscles.
It also give some internal support through its
infoldings, called apodemes.
Apodemes not only increase the area for the
attachment of muscles but also protect soft
internal organs.
6. Exoskeletal covering is segmented,and its
segments are called sclerites.
Each body segment bears a pair of
appantages on its ventral side.
Thus there is 19 pairs of appendages;five pair
of cephalic ,eight pairs of thoracic and six pairs
of abdominal.
7. Cephalic appandages are five pairs in number.
They include the paired
antennules,antennae,mandibles,first maxillae and
second maxillae.
Antennules and antennae are tactile
structures,mandibles are masticatory structures used
to cutting the food into pieces,and the first and
second maxillae serves as feeding food.
8.
9. Thoracic appandages are eight pairs in
number.
It includes first,second and third maxillipede
and five walking legs.
In these first three walking legs are cheliped
and other two are non-cheliped.
10.
11. Abdominal appendages are six pairs in
number.
They are used for swimming and hence called
pleopods.
the last pair of pleopods are called uropods.
the first pleopod is different in two sexes.
