PLENARY

 

The importance of polyps to understand jellyfish diversity, evolution and blooming potential

 

André C. Morandini (1), Ilka Straehler-Pohl (2) and Agustín Schiariti (3)

(1) Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo (USP), Brazil

(2) Medusas Nursery, Private Laboratory for Life cycle, Developmental and Evolutionary Research, Germany

(3) Instituto de Investigación y Desarrollo Pesquero (INIDEP)-Instituto de Investigaciones Marinas y Costeras (IIMyC), Argentina

 

To understand the biology and ecology of metagenetic cnidarians, all life cycle stages must be considered. Although this statement seems obvious, historically the pelagic stage was much more studied than the benthic ones; especially considering scyphozoan and cubozoan species. Any environmental factor or biological phenomenon that affects the polyp populations certainly will have effects on the medusa counterpart, and many of them can lead to aggregation or blooming episodes. Besides several studies on the subject, we are still far from a precise answer on which factors can cause blooms, but we are moving towards a better understanding. Polyps are morphologically much simpler than medusae, and such fact makes it hard to define body characters that can be used for identification purposes. But detailed and long-term observations led researchers to find distinctive features, body patterns and reproductive strategies that enable differentiation of taxonomic units among scyphozoans and cubozoans. Furthermore, the recognition of polyps’ different characters can help researchers to understand the evolutionary patterns observed in the medusa stage, corroborating, refuting or eventually creating new ideas.