The roles of skewers include conducting heat inside the fish as well as forming the shape of fish, which is called 'odorigushi' ("odori" is dancing, "gushi" is a skewer, i.e., literally means "dancing and a skewer") because the fish looks like waving and dancing.
串は魚の形を整える（魚体がうねるように打って「踊り串」などと称する）と共に、伝導熱で中まで火を通す役割がある。