Cubozoan medusae are noted for behavior more complex than other cnidar
ian classes and for possessing rhopalial sense organs that include mul
tiple complex eyes with spherical lenses. Tripedalia cystophora, a sma
ll cubozoan medusa, was the subject of field observations in southwest
ern Puerto Rico concerning the role of its complex eyes. A behavioral
repertoire was established with in situ observations among mangrove pr
op roots. Medusae show an attraction to light shafts that penetrate th
e mangrove canopy and in which their copepod prey are commonly found.
Non-breeding medusae feed actively on copepods in or near light shafts
; breeding males and gravid females do not feed, yet breeding males ex
hibit the highest level of activity in an apparent search for mates. B
ecause mating in T. cystophora can be described as a form of copulatio
n, an image-forming role for the complex eyes in mating behavior is a
logical assumption, but neither observational evidence in this study n
or optical theory supports such a role.