On the occurrence of Laurencia caraibica (Ceramiales, Rhodophyta) in Atol das Rocas, Brazil

Laurencia caraibica P.C. Silva is being referred occurring in Atol das Rocas, a small island located about 147miles off Brazilian northeastern coast. The specimens are characterized by the soft, reduced size thalli with four periaxial cells per each axial segment and tetrasporangia in parallel arrangement; presence of lenticular thickenings in the wall of the medullary cells; epidermal cells near the apex not projected beyond the surface of the thalli; presence of anastomose between branches and the occurrence of secondary pit connections between epidermal cells. In this paper, previously unknown detailed morphological characters are presented and compared to related species

Macroalgal composition and its association with local hydrodynamics in the Laje de Santos Marine State Park, southwestern Atlantic, São Paulo, Brazil

The Laje de Santos Marine State Park (LSMSP), located in southeastern Brazil, is the only marine park in São Paulo State. This conservation unit has been established as a protected area of high biological diversity. Despite its importance for the conservation of the marine biota, little is known about the park's seaweed flora. The objectives of this study were as follows: to furnish increased knowledge of the composition of the macroalgae in the Park area; to relate the area's macroalgal composition to the presence of an important water mass in the region, the South Atlantic Central Water (SACW); and to investigate the possible influence of the Port of Santos on the composition of the macroalgae of the LSMSP. This study registered 31 new records for the LSMSP, 11 for São Paulo State, four for Brazil, one for the western Atlantic and one for the South Atlantic Ocean, in addition to the possible occurrence of one new species of Osmundea (Rhodomelaceae) and one new genus belonging to Ceramiaceae. The taxonomic composition of the macroalgae had a direct correlation with the arrival of the SACW in the summer-fall season. The SACW generated a strong thermocline and increased the supply of nutrients in the water column. Hydrodynamic and dispersion modeling analyses suggested that the Port of Santos influenced the composition of the LSMSP phycoflora.O Parque Estadual Marinho da Laje de Santos (PEMLS), localizado no sudeste do Brasil, é o único parque marinho do litoral paulista. Essa unidade de conservação foi classificada como de "alta diversidade biológica". Apesar da sua importância para a preservação da biota marinha, pouco é conhecido sobre a flora de macroalgas do Parque. Os obejtivos deste estudo foram: aumentar o conhecimento da composição de macroalgas na região do PEMLS; relacionar tal composição com a presença de uma importante massa d'água na região, a Água Central do Atlântico Sul (ACAS); e verificar uma possivel influência do Porto de Santos na composição ficológica do Parque. O presente estudo registrou 31 novas ocorrências para o Parque, 11 para o estado de São Paulo, quatro para o Brasil, uma para o Atlântico Ocidental e uma para o Atlântico Sul, além de duas prováveis novas ocorrências para a ciência: uma espécie de Osmundea (Rhodomelaceae) e um gênero pertencente e Ceramiaceae. Segundo os dados encontrados, a composição de macroalgas tem uma correlação direta com a presença da ACAS no período de verão-outono. Essa frente térmica profunda promove a formação de uma forte termoclina e aumenta o aporte de nutrientes na coluna d'água. Análises dos modelos hidrodinâmico e de dispersão sugerem que o Porto de Santos pode influenciar a composição ficológica do local

Macroalgal composition and its association with local hydrodynamics in the Laje de Santos Marine State Park, southwestern Atlantic, São Paulo, Brazil

The Laje de Santos Marine State Park (LSMSP), located in southeastern Brazil, is the only marine park in Sao Paulo State. This conservation unit has been established as a protected area of high biological diversity. Despite its importance for the conservation of the marine biota, little is known about the park's seaweed flora. The objectives of this study were as follows: to furnish increased knowledge of the composition of the macroalgae in the Park area; to relate the area's macroalgal composition to the presence of an important water mass in the region, the South Atlantic Central Water (SACW); and to investigate the possible influence of the Port of Santos on the composition of the macroalgae of the LSMSP. This study registered 31 new records for the LSMSP, 11 for Sao Paulo State, four for Brazil, one for the western Atlantic and one for the South Atlantic Ocean, in addition to the possible occurrence of one new species of Osmundea (Rhodomelaceae) and one new genus belonging to Ceramiaceae. The taxonomic composition of the macroalgae had a direct correlation with the arrival of the SACW in the summer-fall season. The SACW generated a strong thermocline and increased the supply of nutrients in the water column. Hydrodynamic and dispersion modeling analyses suggested that the Port of Santos influenced the composition of the LSMSP phycoflora

"Alsidium oliveiranum" sp. nov. (Rhodomelaceae, Rhodophyta), an overlooked species from the southwestern Atlantic based on morphology and DNA sequence data

[Abstract] The exploration of seaweed diversity in poorly studied habitats has often led to the discovery of new species. Sand-covered rocks are an example, as they received less attention than sand-free rocky intertidal habitats during seaweed diversity surveys in Brazil. In sand-covered rocks from Espírito Santo and Rio de Janeiro we found an alga whose morphology was unique among rhodomelacean species previously reported in Brazil. With the aim to clarify the taxonomic identity of this species we studied its morphology, as well as its phylogenetic relationships. Molecular analyses resolved this species in the genus Alsidium (tribe Alsidieae) and differed from sequenced congeners with divergences ≥2.5 and 4.2% in the rbcL and cox1 genes, respectively. Morphological characters were in agreement with the genus Alsidium, and differed from other species currently recognized in the genus. The species consisted of a basal crust and scarcely branched erect axes with seven pericentral cells covered by a continuous layer of cortical cells. Reproductive structures were formed on clusters of short determinate branches. Therefore, the new species A. oliveiranum is proposed based on morphological and molecular evidence. Our findings contribute to better understand the diversity of the tribe Alsidieae, which is particularly diverse in the Americas.Xunta de Galicia; GPC2015/025Brasil. Conselho Nacional de Desenvolvimento Científico e Tecnológico; 304899/2017–8Fundação de Amparo à Pesquisa do Estado de São Paulo; FAPESP 2016/50370-

Seasonal Recruitment and Survival Strategies of Palisada Cervicornis Comb. Nov. (Ceramiales, Rhodophyta) in Coral Reefs

As marine tropical ecosystems deteriorate and lose biodiversity, their communities are shifting to dominance of a few species, altering ecosystem’s functioning and services. Macroalgae are are becoming dominant on coral reefs, and frequently observed outcompeting corals. Turf algal assemblages are the base of energy flow in these systems and one of the most abundant types of macroalgae on coral reefs, but little is known about their biology and diversity. Through molecular and morphological analyses, we established the proper identity of the turf-forming species Laurencia cervicornis, and by studying seasonal recruitment and the impact of herbivorous fishes on its abundance, we describe its survival strategy. The molecular analyses using a total of 45 rbcL gene sequences including eight current genera within the Laurencia complex and two new sequences of L. cervicornis, strongly support the new combination of Palisada cervicornis comb. nov. In addition, a detailed morphological characterization including the description of reproductive structures, is provided. P. cervicornis was seen recruiting in all seasons but was typically in low abundance. Specimens grown on tiles in fish exclosure cages were devoured in less than 4 hours when offered to fishes. Even though many species of the Laurencia complex have chemicals that deter herbivory, species within the genus Palisada lack feeding deterrents and are highly palatable. We suggest that P. cervicornis is a palatable species that seems to survive in the community by obtaining a size-refuge from herbivory within turf communities.

Novas ocorrências de macroalgas marinhas bentônicas no estado de Pernambuco, Brasil

Foram realizados estudos na região entremarés de recifes da Praia de Boa Viagem, Recife, nordeste do Brasil, em dezembro de 2009 (período seco) e abril de 2010 (período chuvoso), para analisar a estrutura da comunidade das macroalgas epífitas em outras macroalgas. O material foi coletado em dois trechos recifais, cada um com aproximadamente 30 m de extensão, em diferentes compartimentos favoráveis ao crescimento de macroalgas. Todo o material coletado permaneceu congelado até o procedimento de análise. Os exemplares estão depositados no Herbário do Instituto de Botânica, São Paulo, Brasil (SP). Foram encontradas nove novas ocorrências para a costa pernambucana: Boodlea composita (Harv.) F. Brand, Ceramium corniculatum Mont., Chaetomorpha clavata Kütz., C. nodosa Kütz., Chondracanthus cf. saundersii C.W. Schneid. & C.E. Lane, Cladophora laetevirens (Dillwyn) Kütz., Neosiphonia sphaerocarpa (Børgesen) M.-S. Kim & I.K. Lee, Ulva linza L. e U. prolifera O.F. Müll. Destas, quatro tiveram sua distribuição consideravelmente ampliada ao longo do litoral brasileiro