2. Introduction
About dozen species of fresh water prawns
Atleast, three species, M.rosenbergii, M.
malcolmsonii & M. birmanium
The largest prawn in the world – 300 mm in length;
400 g weight.
5. M. rosenbergii is the largest natantian (swimming) prawn in
the world and belongs to the family
Palaemonidae (refer to Box 1). The adult prawn can easily be
identified from other species in the genus by the following
characteristics:
• Adult male has a pair of very long legs (chelipeds)
• The rostrum is long and bent in the middle with 11–13 dorsal
teeth and 8–10 ventral teeth
• The movable finger of the leg of the adult male is covered by a
dense mat of spongy fur
• Distinct black bands on the dorsal side at the junctions of the
abdominal segments
6. The body consists of the head (cephalothorax) and
tail (abdomen) and is divided into 20 segments.
Of these segments, 14 are in the head and covered
by a shield known as the carapace.
The front portion of the head has 6 segments, and
features:
• stalked eyes
• first antennae
• second antennae
• mandible, used to grind food
• first maxillae, which transfer food into the mouth
• second maxillae
7. The rear portion of the head (thorax) has 8
segments, each of which has a pair of appendages:
• 3 sets of maxillipeds (function as mouthparts)
• 5 sets of legs (pereiopods)
8. Life cycle
There are four distinct phases in the prawn life cycle:
Egg, Larva (zoea), postlarva (PL) and adult.