External features of Penaeus
Cephalothorax antennule antenna antennal flagellum scaphocerite carapace maxilliped pereopods compound eye rostrum Abdomen pleopods abdominal segments Tail uropods telson
	In addition to the paired eyes, there is a median light-sensitive structure, the "becoculaire". It is situated immediately below the rostrum. It is a complex structure, consisting of the naupliar eye and dorsal and ventral frontal organs, with nerves connecting directly to the nearby brain. It is believed that its only function is light detection, but its physiological role has not been determined (Dall et al., 1990).