GENUS : PENAEUS

Adrostral groove and carine long, reaching posteriorly much beyond midlength, usually almost to posterior margin of carapace

Gastofrontal carina present

Thelycum with circular to substriangular plate on seventh thoracis sternite and two lateral plates on eight thoracis sternite

Sub genus : Melicertus

Adrostral groove and carina short, not raching posteriorly much beyond the midlength of carapace

Gastrofrontal carina absent

Hepatics carina absent or ill defined

Sub genua : Fenneropenaeus

Thelycum with a circular to subtriangular plate on seventh thoracis sternite and two lateral plates on eight thoracic sternite

Sub genus : Melicertus

Thelycum with a large triangular plate on seventh thoracic sternite and a pouch like structure on eight thoracis sternite

Sub genus : Marsupenaeus

Hepatic carina prominent

Thelycum of closed type

Petasma with ventral costa long reaching distal margin of lateral lobe

Sub genus : Penaeus