Introduction
Macrobrachium Malcolmsonii (formerly known as Palaemon Malcolmsonii) or monsoon river shrimp is an economically important nocturnal omnivorous freshwater shrimp that inhabits the rivers, lakes, and ponds of India, Pakistan, and Bangladesh. They are 25 to 40 cm long, relatively hardy, and prefer slow, clear water. They are bottom-dwellers that breed during monsoon months.
Classification of Palaemon malcomsonii
| Taxonomic Rank | Name | Characteristics |
|---|---|---|
| Kingdom | Animalia | Multicellular eukaryotes |
| Phylum | Arthropoda | Segmented invertebrates with jointed appendages |
| Subphylum | Crustacea | Mostly aquatic arthropods with exoskeleton |
| Class | Malacostraca | Largest class of crustaceans with ten legs (decapods) |
| Order | Decapoda | Ten-legged crustaceans including shrimps and crabs |
| Suborder | Dendrobranchiata | Prawns with branched gills and distinct reproductive traits |
| Superfamily | Penaeoidea | Prawns with elongated bodies and well-developed rostra |
| Family | Penaeidae | Commercially important penaeid shrimps |
| Genus | Palaemon | Large penaeid shrimps including farmed and wild species |
| Species | malcolmsonii |
Habit and habitat
Palaemon is found in fresh-water streams, rivers, ponds and lakes. The animal is nocturnal, hiding at the bottom during the day and coming to the surface at night in search of food. Distribution : Commonly found in India.
Comments on Palaemon malcomsonii
- Commonly called as prawn.
- Body is elongated, spindle-shaped, bilaterally symmetrical and deep orange coloured when preserved and measuring about 25 cm in length.
- Divisions of the body are cephalothorax, abdomen and telson.
- Cephalothorax is made up of 5 head and 8 thoracic segments.
- Carapace is anteriorly produced into sawtoothed rostrum. There are two prominent eyes on the head.
- Abdomen is made up of 6 segments. It is dorsally rounded, laterally compressed and nonnally bent under the cephalothorax so that the animal looks like comma.
- There are 19 pairs of appendages, one pair in each segment.
- The cephalic appendages comprise of antennules, antennae, mandibles, maxillulae and maxillae.
- A large platelike antennal used as a rudder in swimming.
- Thoracic appendages are I maxillipedes, II maxillipedes, III maxillipedes and 5 pairs of jointed walking legs.
- First abdomen somite is not reduced. Rest five abdominal segments contain paired biramous swimming pleopods. Vlth abdominal segment contains paired uropods and a telson.
- Development includes nauplius larva.
Special features
Prawns have edible importance and they have great educational importance. They are most familiar animals for dissection to understand invertebrate anatomy.
Identification
Since the specimen is larger than Penaeus, contains spatulate uropods and all above characters, hence it is Palaemon malcolmsollii.