Visual control of steering in the box jellyfishTripedalia cystophora

Abstract

SUMMARYBox jellyfish carry an elaborate visual system consisting of 24 eyes, which they use for driving a number of behaviours. However, it is not known how visual input controls the swimming behaviour. In this study we exposed the Caribbean box jellyfish Tripedalia cystophora to simple visual stimuli and recorded changes in their swimming behaviour. Animals were tethered in a small experimental chamber, where we could control lighting conditions. The behaviour of the animals was quantified by tracking the movements of the bell, using a high-speed camera. We found that the animals respond predictably to the darkening of one quadrant of the equatorial visual world by (1) increasing pulse frequency, (2) creating an asymmetry in the structure that constricts the outflow opening of the bell, the velarium, and (3) delaying contraction at one of the four sides of the bell. This causes the animals to orient their bell in such a way that, if not tethered, they would turn and swim away from the dark area. We conclude that the visual system of T. cystophora has a predictable effect on swimming behaviour.

What insects can tell us about the origins of consciousness

“…It has a well-developed geosense and visual sense thanks to 24 lensed eyes distributed around the body (110,111), yet the nervous system is entirely decentralized. Sense organs independently modulate activity in regions of the sensory net and muscle walls to steer the animal (112). The outcome of local sensory input acting on local muscle activity is an adaptive change in the swimming direction and speed of the animal (112), but the simple behavioral control system is entirely decentralized.…”

“…Sense organs independently modulate activity in regions of the sensory net and muscle walls to steer the animal (112). The outcome of local sensory input acting on local muscle activity is an adaptive change in the swimming direction and speed of the animal (112), but the simple behavioral control system is entirely decentralized. Although such systems manifest the appearance of adaptive and dynamic targeting, they are nothing more than simple decentralized stimulus-response systems.…”

The search for ancestral nervous systems: an integrative and comparative approach

“…These structures both serve to increase the rate of flow of ejected water from the subumbrellar cavity, but they also play a significant role in turning behavior through asymmetrical contractions and directional nozzle formation (Gladfelter, 1973;Petie et al, 2011). The two structures are considered to be analogous rather than homologous, as in cubomedusae they are direct extensions of the subumbrella, and in hydromedusae they are separated from the subumbrella by the nerve rings.…”

Cnidaria

“…The other, larger lens eye is oriented downwards. The eyes allow the medusae to navigate effi ciently through their mangrove habitat, to avoid predators and actively pursue prey (Garm et al 2007a(Garm et al , b , 2008(Garm et al , 2012Petie et al 2011 ).…”