Mosquito pupa. Light micrograph of the pupa of a mosquito (family Culicidae) at the surface of water, showing its fused head and thorax (cephalothorax, centre) and segmented abdomen (right). Mosquito pupa are aquatic and breath through spiracles located on their abdomen, or through a siphon (breathing tube) on the end of their body. After a few days, depending on the water temperature, they rise to the surface of the water, the cephalothorax (fused head and thorax) splits and the adult emerges (seen here). Magnification: x42, when printed 10 centimetres wide.