  Patterns in biology can be considered as predetermined, or arising from a
self-organizing instability. Variability in the pattern can thus be interpreted
as a trace of an instability, growing out from noise. Variability can thus hint
toward an underlying morphogenetic mechanism. Here we present the variability
of the gastrovascular system of the Jellyfish Aurelia. In this variability
emerge a typical biased reconnection between canals, and correlated
reconnections. Both phenomena can be interpreted as traces of mechanistic
effects, the swimming contractions on the tissue surrounding the gastrovascular
canals, and the mean fluid pressure inside them, respectively. This reveals the
gastrovascular network as a model system to study morphogenesis of circulation
networks and the morphogenetic mechanisms at play.
