• It is the 4th stage in the life cycle of crustacean.

• The body is divisible into cephalothorax and a long segmented appendage.

• Cephalothorax is covered over by carapace and bears paired compound eyes and paired appendage.

• The carapace is produces into a long and pointed rostrum.

• Cephalothorax also pairs buds for 6 pairs of thoracic appendages.

• The abdomen has 6 segments with paired rudiments of abdominal appendages.

• It metamorphosis into metazoan and ultimately into megalopa.