Explain the palaemon of arthropoda which belongs to non chordate phyla?

The palaemon are also known as prawns. They reside in river and feed on algae, mosses and insects. Their main respiratory organs are gills. They have unisexual and bisexual forms and show sexual dimorphism. They are edible. Their body is divided into cephalothorax and abdomen. The cephalothorax has 26 appendages while the abdomen has 12 appendages. So, in total there are 38 appendages. They help in feeding, swimming and balancing. A telson is also formed at the posterior end of abdomen.