S. califoricum

Multi-scale tracking of S. californicum (Acorn worm) larva reveals a behavior that is quite distinct from those of other larvae behaviors presented here. In particular, the larvae have a highly dynamic orientation that is not aligned with the gravity axis, in striking contrast to highly gravitactic behaviors of other larvae. The larvae show repeated "dives" and "tumbles" and indeed challenged our (older) tracking system to keep up! One hypothesis for this more "complex" behavioral repertoire of these larvae is that they are significantly older (28 days post-fertilization) than the other larvae, allowing for a the development of more complex behaviors.