MORPHOLOGICAL AND MOLECULAR EVIDENCES SUGGEST A NEW COMBINATION FOR LAURENCIA COELENTERATA (CERAMIALES, RHODOPHYTA) FROM THE TROPICAL ATLANTIC OCEAN Mutue T. Fujii1*, Abdiel Jover C. 2, Abel Sentíes3, Jhoana Díaz-Larrea3, Valéria Cassano4, Ligia Collado-Vides5 & Arsenio Areces6 1. Núcleo de Pesquisa em Ficologia, Instituto de Botânica, São Paulo, Brazil, *mutue.fujii@pq.cnpq.br; 2. Dpto. de Biologia, Univ. del Oriente, Santiago de Cuba; 3. Dpto. Hidrobiología, Univ. Autónoma Metropolitana, Iztapalapa, México, D.F.; 4. Dpto. Botânica, Univ. de São Paulo, São Paulo, Brazil; 5. Departament of Biological Sciences, Florida International University, Miami, Florida, USA; 6. Instituto de Oceanologia, Habana, Cuba, and Dpto. Oceanografia, Univ. Federal de Pernambuco, Recife, Brazil. INTRODUCTION MATERIAL AND METHODS Laurencia coelenterata is a small sized species, first collected in 2008, in Eastern Cuban Archipelago. A detailed taxonomical study revealed vegetative and reproductive characteristics belonging to the genus Osmundea, such as two pericentral cells per each axial segment, tetrasporangia cut off randomly from cortical cells, and filament-type spermatangial branches developed in a cup-shaped spermatangial pit. These characteristics are in disagreement with the original circumscription of the species. The phylogenetic position of the present species was inferred by analysis of the 34 chloroplast-encoded rbcL gene sequences. The range of genetic variation found in the analysis also supports the new taxonomical assessment of L. coelenterata as Osmundea coelenterata. 50 µm Morphological characteristics Samples were collected in the Cazonal beach, Santiago de Cuba (19° 53' 39'' N, 75° 31' 8.7'' W). Cazonal is a biogenic sand beach, 60 cm depth, with isolated limestone and Thallasia testudinum bed in the bottom. It is located 52 km east from the city of Santiago de Cuba (Fig. 1-2). Transverse and longitudinal hand sections were made with a stainless-steel razor blade and stained with 0.5% aqueous aniline blue solution, acidified with 1N HCl, to highlight the diagnostic features. Extraction, amplification of DNA and sequencing followed the usual protocols. A total of 34 rbcL sequences were used in this study, including two newly generated sequences and the rest obtained from .GenBank. Phylogenetic relationships were inferred with PAUP * 4.0b10 and MrBayes v.3.0 beta 4. Maximum parsimony (MP) analyses were performed using PAUP* and a heuristic search with 1,000 random additions. The model used in the Bayesian analysis (GTR + I + G) was selected based on maximum likelihood (ML) ratio tests implemented in Modeltest version 3.7. Maximum likelihood (ML) analysis was conducted with TOPALi v2. Maximum likelihood and MP analyses were subjected to bootstrap resampling to estimate robustness. p a p 3 4 50 µm 100 µm 1 mm 8 10 9 a p p 5 6 4 Fig. 3-6. Laurencia coelenterata (Paratype). 4. surface view of the cortical cells with secondary pit connections (arrow). 4-5. Cross section of the thalli showing 2 pericentral pericentral cells per each axial segment. 7 11 1 12 2 2 mm Fig. 1. Google map showing Laurencia coelenterata collecting site: Santiago de Cuba. Fig. 2. View of the Cazonal beach, Santiago de Cuba, during high tide. Representatives of Laurencia complex 13 14 Fig. 7-14. Laurencia coelenterata from Cuba. 7. Freshly collected specimens. 8-9. Cortical cells in surface view and corss section view, respectively. Arrows indicate secondary pit connections. 10. Cross section of the thallus. 11. Longitudinal section through a mature cystocarp. 12. Longitudinal section through a spermatangial pit, showing remified filament type spermatangial branches. 13-14. Longitudinal sections through the tetrasporangial branches, showing tetrasporangia originated from cortical cells, and showing right angle arrangement of the tetrasporangia (scale bar = 50 µm in 8-9, 12, 14; 100 µm in 10, 11, 13). 3 Laurenciella Laurencia translucida Laurenciella sp. Palisada Laurencia Laurenciella marilzae L. aldingensis L. caduciramulosa L. catarinensis Chondrophycus Osmundea Laurencia dendroidea Palisada perforata P. furcata P. flagellifera Yuzurua Figure 15. Bayesian phylogram inferred from analyses of rbcL sequences for 34 Laurencia complex taxa and one outgroup species. Numbers above branches correspond to support values for Bayesian inference posterior probability/maximum likelihood bootstrap/and maximum parsimony bootstrap, respectively. CONCLUSIONS  The specimens collected in Santiago de Cuba are morphologically identical to Laurencia coelenterata described from Dry Tortugas, Florida, USA.  However, detailed morphological analyses on Laurencia coelenterata revealed characteristics typical of the genus Osmundea, including two pericentral cells per each axial segment, filament type spermatangial branches, and tetrasporangia cut off randomly from cortical cells.  The phylogenetic position of this species inferred by analysis of the chloroplast-encoded rbcL gene sequences formed a well-supported clade with other species of Osmundea corroborating the morphological data. Finacial support: Osmundea lata O. sanctarum O. truncata  Osmundea truncata from Ireland is the nearest species from Laurencia coelenterata, although the gross morphology of both species are completely distinct.  The divergence of Laurencia coelenterata from other related species was 5.5–11.5%, which confirms that it constitutes an authentic taxonomic entity.  The morphological and molecular evidence suggests a new combination for Laurencia coelenterata as Osmundea coelenterata, which is being provided.  This is the first report of Osmundea species in the Cuban archipelago.