Biodiversity and Evolution

Biodiversity and Evolution of Hydrozoans

Hydrozoans are aquatic animals widespread all over the world and count about 3800 species, few of which are used as models in many biological fields. Their anatomy is relatively simple and normally they have three life stages: a sessile polyps, a planktonic medusa and a larva. They show a diverse array of morphological, reproductive and ecological stages and in some cases they have evolved a symbiotic lifestyle, being specifically associated with other organisms, such as corals, sponges, crustaceans and many other.


(Hydrozoan polyps associated with octocorals, hard corals and sponges)

Many hydrozoan groups are understudied and poorly known, especially concerning their real diversity, distribution and ecology. We have been working on some groups of these animals, mainly studying their morphological and molecular diversity. Most of the species we are focusing on live in symbiosis with other organisms, and in particular hard and soft corals, bryozoans, and sponges. Using different types of microscopy, ecological surveys and molecular techniques, we are investigating the biodiversity of selected families, especially in the tropical waters of the Maldives, but also in other localities such as the Red Sea and the Mediterranean. So far, several new species have been found and we are studying their relationship with their hosts, trying to understand how they interact with them and how they have reached their current diversity. Moreover, we are also studying the biogeographical patterns of some species, in order to understand how they are distributed and the possible causes and processes that shaped this distribution. Finally, collecting data for several species using different disciplines will allow us to study the evolution of certain important features. To achieve these results, we are collaborating with other experts in the field from both Italy and other countries, in order to obtain new samples and, more importantly, to have different and fresh perspectives and point of views.


(Hydrozoan medusae few days after release from polyps)