Meeting Abstract
Jellyfish are important components of marine foodwebs and form blooms that negatively impact human enterprise. Jellyfish of the genus Aurelia (Class Scyphozoa) are common bloom-formers in the Gulf of Mexico (GoM). Aurelia have a multi-modal lifecycle where the perennial polyp produces seasonal jellyfish. Tolerance limits for survival are crucial to understanding present jellyfish polyp distribution and how distribution may change in climate change scenarios. We sampled and barcoded two Aurelia jellyfish from the GoM and an Aurelia species native to Japan: Aurelia sp. 9, a possible new species found offshore (Aurelia sp. new) and the invasive A. coerulea. Using controlled laboratory experiments we determined the temperature and salinity tolerance limits for polyps of the three species. We find that A. sp. 9 and A. coerulea were tolerant of a broad range of temperatures and salinities, but differed in tolerance limits, suggesting potential differences in habitat and resilience to climate change. A. sp. 9 was most tolerant of high temperatures and low salinities, such as those found in the estuaries of the GoM. Summer high temperatures in the coastal GoM exceed the upper thermal tolerance limits of A. sp. new and A. coerulea. This confirms that A. sp. new is an offshore species and suggests that the coastal GoM may not be suitable for the invasive A. coerulea. Ocean temperature increase may negatively impact resident Aurelia species and deter Aurelia coerulea from invading the GoM. This is the first account of Aurelia sp. new and the first report of temperature and salinity ranges limits for Aurelia species.
