Behavioural and oceanographic isolation of an island-based jellyfish (Copula sivickisi, Class Cubozoa) population

Abstract Cubozoan jellyfish are classified as plankton despite the strong swimming and orientation abilities of cubomedusae. How these capabilities could affect cubozoan population structures is poorly understood. Medusae Copula sivickisi can uniquely attach to surfaces with sticky pads on their bells. Biophysical modelling was used investigate spatial scales connectivity in a C. population. When medusae were active at night they maintain observed distribution fringing reef if attached when current speed exceeded moderate threshold. This behaviour facilitated isolation reefs Magnetic Island, Queensland, Australia. Within this distribution, there considerable within bay retention rarely travelled > 3 km. The few (< 0.1%) lost from island habitat largely advected into open water away mainland coast which lies 8 km island. Given that successful emigration unlikely, probably represents stock ecologically distinct any populations. cosmopolitan contain incipient or cryptic species given small demonstrated here.