Ximenes C.F., Cassano V., Oliveira-Carvalho M.F., Bandeira-Pedrosa M.E., Gurgel C.F.D., Verbruggen H. & Barreto-Pereira S.M. (2017)
Systematics of the genus Halimeda (Bryopsidales, Chlorophyta) in Brazil including the description of Halimeda jolyana sp. nov.
Phycologia 56: 369-381


The genus Halimeda has a wide geographical distribution in tropical to subtropical regions of the world. Molecular studies have revealed cryptic and pseudo-cryptic species and a strong biogeographic imprint in phylogenies. To date the Brazilian Bryopsidales diversity has only been studied from a morphological perspective. In the present study we revised Brazilian Halimeda diversity based on molecular data (DNA barcode assessments of the tufA marker and multi-gene concatenated phylogenies) as well as morphological observations. Of the seven recognized morpho-species only three were confirmed by molecular data: Halimeda opuntia, H. simulans and H. incrassata. The remaining four species referred to as H. aff. cuneata, H. aff. gracilis, H. aff. tuna and H. aff. discoidea showed morphological similarities with known species but their sequences did not group with sequences of specimens from type localities, indicating the presence of cryptic diversity. Among the four taxa, H. aff. cuneata is so far endemic to Brazil and herein described as a new species, H. jolyana. The remaining three taxa in species complexes require further studies using a global sampling design. The evolutionary and biogeographic origins of the Brazilian Halimeda flora are discussed based on new molecular phylogenetic hypotheses.

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