Genetic diversity and clonality of the invasive coral Tubastraea spp  on the coast of Rio de Janeiro
Channel: Encontro Recifal Brasileiro
Date: 01/07/2020

Ligia Massa Bacellar Mendes; Kátia Capel; Carla Zilberberg

Tubastraea spp. (Anthozoa, Dendrophylliidae) are azooxantellated corals native to the Indo-Pacific with a wide worldwide distribution. The genus was registered on oil platforms off the coast of Rio de Janeiro, in the late 1980s, and is currently found throughout the Brazilian coast, threatening native species. The aim of this study was to evaluate the genetic diversity and clonality of T. coccinea and T. tagusensis in locations close to the initial point of invasion. Three regions were sampled for T. coccinea ( ncoras: N = 27, Baía da Ilha Grande-BIG: N = 88 and Paraty: N = 47) and four for T. tagusensis ( ncoras: N = 32, Cagarras: N = 32, BIG: N = 80 and Paraty: N = 48). 9 and 10 microsatellite sites were used for T. coccinea and T. tagusensis, respectively, with only 12 and 10 lines of multiple single lines (MLL) being found. Each of the regions evaluated for T. coccinea has a different dominant MLL, with MLL dominant in  ncoras or a single one shared among all regions. The occurrence of a dominant and exclusive MLL in Paraty may indicate colonization separate from other areas.  ncoras had the greatest genetic diversity found, followed by Paraty and BIG. For T. tagusensis,  ncoras and BIG presented clonal diversity and richness values similar to those observed in T. coccinea higher than those found in Cagarras and Paraty. Unlike T. coccinea, as regions sampled for T. tagusensis were dominated by the same MLL, altering a great connection between studied areas, either through the natural dispersion of larvae or in vector transport. The results bring new information about an invasion on the coast of Rio de Janeiro, showing all the sampled regions are connected and clonal reproduction is predominant. Such information is crucial for planning management, containment and prevention of future invasions.