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Taxonomy and phylogeny of Lithophylloideae (Rhodophyta) from Brazil

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Author(s):
Beatriz Nogueira Torrano Silva
Total Authors: 1
Document type: Doctoral Thesis
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
Defense date:
Examining board members:
Mariana Cabral de Oliveira; Valéria Cassano; Carlos Frederico Deluqui Gurgel
Advisor: Mariana Cabral de Oliveira; Rafael Riosmena Rodríguez
Abstract

Lithophylloideae is a subfamily within Corallinaceae including both articulated and non-articulated genera. This work is the first effort to access the specific diversity for Amphiroa, Lithophyllum, Paulsilvella and Titanoderma for Brazil based on a sum of morphological anatomical, ecological and molecular data, including also the tools applicability evaluation. From the 26 species found, are Amphiroa, eight are Lithophyllum, two are Titanoderma and one is the first register for Paulsilvella for Atlantic waters: Amphiroa rigida, A. vanbosseae, Amphiroa sp. 1, Amphiroa sp. 2, Amphiroa sp. 3, Amphiroa sp. 4, six criptic species for the A. fragilissima Complex, three cryptic species for the A. beauvoisii Complex, Lithophyllum atlanticum, L. corallinae, Lithophyllum cf. depressum, Lithophyllum sp. 1, Lithophyllum sp. 2, Lithophyllum sp. 3, Lithophyllum sp. 4, Lithophyllum cf. margaritae, Titanoderma pustulatum, T. prototypum and Paulsilvella huveorum. For the molecular characterization four markers were used: UPA, COI-5P, psbA and rbcL-3P, which have attended to two the delimitation of species and also to the evaluation of these markers as DNA Barcodes for the species of Lithophylloideae within the context of variability found on the Brazilian coast. For these two purposes we have applied five clustering methods, based on the Divergence Rates, ABGD, MDS, PTP and SPN. Conflicting cases were also observed for values of barcoding gap. The four molecular markers are reliable for species delimitation within the Lithophylloideae, providing good support values for the species and significant amounts of barcoding gap. Nevertheless, given the possibility of using the rbcL marker also for phylogenetic purposes, we emphasize the applicability of rbcL-3P as the most appropriate marker, in case there is a need to indicate a single marker as DNA Barcode for this group alga. A phylogenetic inference for the Lithophylloideae included the first sequences for Paulsilvella and used psbA, rbcL-3P and SSU rDNA. We found that Amphiroa is monophyletic while Lithophyllum and Titanoderma are probably polyphyletic. Additionally, Paulsilvella may represent the first morphological form of the subfamily. Amphiroa, Lithophyllum and Titanoderma distribution along the Brazilian coast have allowed a new discussion concerning the benthic macroalgae distribution to the country, adding two new factors to this scenario: the coastal currents movement and the South Atlantic Gyre. The molecular data have also allowed accessing the preferences according to the depth on the water column for the 26 species. The major diversity for Amphiroa grows at the intertidal, while Lithophyllum and Titanoderma diversity is higher at the subtidal and Paulsilvella is restricted to the subtidal. There are eight species restricted to the intertidal and ten restricted to the subtidal (including P. huveorum), what addresses to a need to include these both environments on diversity studies for the Florideophycideae otherwise it will imply the existence of an unexplored diversity (AU)

FAPESP's process: 10/19234-3 - Taxonomy and phylogeny from the subfamily Lithophylloideae in Brazil.
Grantee:Beatriz Nogueira Torrano da Silva
Support Opportunities: Scholarships in Brazil - Doctorate