Exploring eusociality in a marine vertebrate- relatedness, dispersal and population connectivity in Risor ruber

The apex of animal social organization is eusociality, a social system where only one cast creates offspring, defended and cared for by obligate sterile workers and warriors. Most eusocial systems occur in terrestrial invertebrates, such as bees, ants and wasps.

The only known eusocial vertebrates are naked mole rats, and the only known eusocial marine animals are snapping shrimp in the genus Synalpheus. To date, no eusocial marine vertebrate has been recorded. Here, we propose to examine whether a marine vertebrate, the Tusked goby (Risor ruber), has evolved a eusocial system.

R. ruber is an ideal candidate for eusociality because (1) small gobies have the potential for kin selection and (2) R. ruber is ecologically similar to Synalpheus shrimp, occupying similar sponges and exhibiting a cryptic lifestyle with no obvious dispersal.

We will explore eusociality in R. ruber by studying relatedness, dispersal and behaviour in groups around Carrie Bow Cay, Belize, as well as along the Mesoamerican Barrier Reef.

Our research will be among the first to focus on a cryptobenthic reef fish in the Caribbean, a group that plays an important, yet often overlooked, role in coral reef ecosystems. Thus, regardless of R. ruber's eusociality, our study will provide critical baseline data for coral reef science.

If we discover eusociality in R. ruber, this will lead to new research avenues into the dispersal of marine vertebrates, the role of the biphasic life cycle in marine environments and the evolution of social and mating systems in fishes and other vertebrates.