1. Penaeus is a marine and deep-sea form, chiefly inhabiting tropics.
2. It is found in American water.
3. It is commonly called as prawn.
4. The preserved specimen is orange-pink in colour having thin integument.
5. Body is divided into an anterior rigid cephalothorax, posterior flexible abdomen and a post segmental terminal telson. All these divisions contain appendages.
6. Cephalothorax is formed of 6 cephalic and 8 thoracic segments. Head contains 2 prominent eyes, very long antennae and short antennules.
7. Endopodite of the first maxillula is elongated and segmented.
8. Walking legs are attached to thorax and the first three pairs of legs are chelate. Each leg bears exopodite and endopodite.
9. Abdomen consists of 6 segments and contains swimmerets of biramous swimming pleopods. They lack finger-like processes called appendix internae on their exopodites. Abdomen is laterally compressed but not bent sharply. Pleopods are biramous and devoid of appendix internae.
10. Pleura of the second abdominal segment do not overlap those of the first.
Source:
1. Practical Zoology Invertebrates by S.S.Lal. 2. A Manual of Practical Zoology Chordates by Dr. P.S. Verma.
