Taxonomy and zoogeographical affinities of the Crustacea (Decapoda & Peracarida) fauna of the remote oceanic archipelago Trindade and Martin Vaz (Brazil)

• Grant number: 25/07925-7
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2025
• End date: May 31, 2029
• Field of knowledge: Biological Sciences - Zoology - Taxonomy of Recent Groups
• Principal Investigator: Marcos Domingos Siqueira Tavares
• Grantee: Marcos Domingos Siqueira Tavares
• Host Institution: Museu de Zoologia (MZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

How is marine biota formed on a remote, oceanic, volcanic island? Trindade and Martin Vaz (TMV) are younger (3.5 and 1.5 million years old, respectively) than the adjacent continental shelves (~80 million years old), so their coastal fauna is composed of migrants that settled after cooling: Atlantic American and African, amphi-Atlantic, insular, circumtropical and endemic species. On a remote island, the biota is a mosaic of different affinities, but what are the components of this mosaic? Which one predominates? Is it a general pattern or taxon-dependent? The incipient taxonomic knowledge contrasts with the immense interest that the TMV fauna arouses: (i) how representative are Atlantic American and African, amphi-Atlantic, insular, circumtropical and endemic species for the biodiversity in TMV?; (ii) how much of the taxonomic composition of TMV is shared with the other oceanic islands of the South Atlantic (São Pedro and São Paulo, Rocas, F. de Noronha, St. Helena, Ascenção)?; (iii) how much endemism occurs in TMV and what are the patterns of endemism when considering all the oceanic islands of the South Atlantic? In case studies with Decapoda, we have shown that the fauna is a mosaic of western and eastern Atlantic, amphia-Atlantic, circumtropical, insular and endemic elements (Anker et al. 2016; Ferreira & Tavares 2017; Tavares et al. 2017; Lima et al. 2019: Tavares & Mendonça 2022). However, if the western Atlantic component seems to predominate, it remains to be established whether this is a general pattern or whether it varies according to taxon. With echinoderms, we showed that groups of Echinoidea, Holothuroidea and Asteroidea also have greater affinity with the fauna of the western Atlantic (Martins et al. 2016; Cunha et al. 2020). The USP Zoology Museum has in its collections a significant amount of material from TMV. This material forms the main basis for the development of this project. (AU)