(1) Any particular abdominal metamere usually consists of only two sclerites, the tergum and sternum.(2) In the vertebrates the metamere is evident in the embryonic stages and tends to disappear in the adults.(3) Rudimentary tracheal metameres invaginate but lack primary branching and interconnections.(4) The metameres are visible rings on the outside and are separated by partitions on the inside.(5) An organism is considered metameric when its body is mostly formed of serially repeated anatomical units called metameres .
