in taxon Arthropoda arthropod sternum Ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the subunits are called sternites, and may also be modified on the terminal abdominal segments so as to form part of the functional genitalia, in which case they are frequently reduced in size and development, and may become internalized and/or membranous. Wikipedia:Sternum_(arthropod) sternum this term should be ceded to the arthropod anatomy ontology FBbt:00004557 HAO:0000956 UBERON:0003130 multicellular anatomical structure