Phylogeographic, genomic and transcriptomic analyses of Actinostella flosculifera (Le Sueur, 1817) (Cnidaria; Anthozoa; Actiniaria) and a population study of the East coasts of Central and South America and West Africa

Abstract

The Cnidaria phylum is composed of invertebrate organisms, mainly marine, such as jellyfish, corals, sea anemones and sea wasps, among others. Cnidarians are characterized by their ability to produce urticating organelles called cnidocysts, which can be classified according to their type (specialized organelle) or their function (attack, defense or the formation of an external tube). This project will study a complex of individuals from different populations of the species Actinostella flosculifera (Le Sueur, 1817) (Actiniaria), which is characterized by a collar or marginal ruff, formed by a series of papillae fused between the column and the margin, as well as longitudinal rows of warts from the lower fringe to the middle of the column, a well-developed pedal disc and 48 tentacles arranged in four cycles, simple, conical and smooth. Since its discovery in St. Thomas in the Virgin Islands (Caribbean Sea) in 1817, a series of morphological and chromatic variation has been reported throughout West America and East Africa. Likewise, the relationships between the different populations of the A. flosculifera complex and the potential for finding cryptic species are still uncertain. However, there are no studies on this species from a molecular point of view or comparisons at the population level. This project proposes the collection of specimens in the rocky intertidal of nine localities distributed in five countries in the Atlantic Ocean and A. bradleyi (Verrill, 1869) will also be collected at two localities in Western America as an outgroup. To achieve this objective, their external and internal morphology and diversity of cnidocystes will be compared. Next generation sequencing (NGS) ultraconserved element (UCE) and exon loci sequences, and traditional nuclear (18S rDNA, 28S rDNA, ITS1+ITS) and mitochondrial (12S rDNA, 16S rDNA, COI and COIII) markers will be used to understand the origin and genetic and morphological variations of the Actinostella complex. In addition, two sequencing methods (Illumina and Oxford Nanopore) will be used for whole genome description and toxin identification by transcriptome sequencing. It is expected that this study will contribute to the knowledge of the distribution of the species, and to understand the interpopulation relationships, biogeographical patterns, its evolutionary history and molecular composition in more detail. (AU)