The New Zealand sand dollar (Fellaster zelandiae) is a key benthic-pelagic coupler and bioturbator endemic to Aotearoa New Zealand. New Zealand spans 12 degrees in latitude. Marine invertebrates like Fellaster encounter a range of environmental variables, including: temperatures from 5-24 °C, variable primary productivity, a range of calcite saturation, different levels of pH, and different wave exposure. Future ocean conditions are predicted to have uneven changes to all these variables and investigations into multi-stressor have yet to fully predict marine invertebrate responses.
As a species with limited mobility, sand dollar genetic dispersal relies on planktonic larval stages to connect populations intergenerationally. Fellaster was used as a model organism to investigate multiple environmental factors’ effect on early life-stages of marine invertebrates. Adult specimens were taken from a range of locations across 10 degrees of latitudes across the country and were spawned for investigation of thermal windows and development times. Larvae were reared in 4-day and 27-day experiments testing the thermal windows and multivariate development of this species from the embryonic stages through larval development and up to the juvenile metamorphosis. Population differences were compared to determine environmental envelopes, enabling predictions regarding future range shifts and local adaptation.