The photocyte of Arachnocampa luminosa was found to contain a circular nucleus, and large amounts of ribosomes, smooth endoplasmic reticulum, mitochondria, and microtubules. Instead of having photocyte granules, the photocytes of the organism were shown to undergo the luciferase reaction in their cytoplasm. The cells do not have a golgi apparatus or rough endoplasmic reticulum and were found to be 250 micrometers by 120 micrometers overall with a depth of 25 to 30 micrometers.