Checklist of phytobenthos from Boipeba Island , Bahia , Brazil , emphasizing the morphological features of Nitophyllum punctatum ( Rhodophyta , Ceramiales )

We report here the results of a survey of the phytobenthos of Boipeba Island, Bahia state, Brazil. Samples were collected during three periods (July 2007 and March and December 2012) in the intertidal regions of offshore reefs near the beaches at Ponta dos Castelhanos, Bainema, Moreré, and Tassimirim. A total of 159 taxa were identified: Rhodophyta (83), Chlorophyta (52), Heterokontophyta/Phaeophyceae (21), Cyanobacteria (02), and Magnoliophyta (01). The most representative orders were Ceramiales (Rhodophyta), Bryopsid ales (Chlorophyta), and Dictyo tales (Heterokontophyta/Phaeophyceae) with 30, 23 and 15 taxa respectively; vouchers were deposited in the herbarium of the Universidade Estadual de Feira de Santana (HUEFS). This work adds 150 new taxa to those already known for Boipeba Island, including Nitophyllum punctatum (Stackh. in With.) Grev., whose occurrence is now confirmed for the coast of Bahia. The number of species identified in this study was elevated in comparison with previous phytobenthos studies undertaken on Brazilian islands.


INTRODUCTION
Bahia has the most extensive shoreline (approximately 1,100 km) of any Brazilian state (Bahia 1999), comprising a wide variety of coastal environments and one of the most highly diverse phycological floras in the country (Pereira 2002;Nunes and Guimarães 2008;Bicudo and Menezes 2010).
Although the phycological benthic marine flora of Bahia has been relatively well studied (Nunes 1998;Széchy and Paula 2010;Creed et al. 2010;Moura 2010;Santos and Moura 2011;Alves et al. 2011aAlves et al. , 2011bAlves et al. , 2012aAlves et al. , 2012bAlves et al. , 2012c;;Jesus 2012;Almeida et al. 2012;Almeida et al. 2013;Torrano-Silva and Oliveira 2013;Almeida et al. 2014;Moura et al. 2014a), there is still much to be discovered about its coastal ecosystems (especially along the extreme northern and southern beaches) and oceanic islands (such as the Abrolhos Archipelago), as well as the Todos os Santos and Camamu bays and their associated islands (such as Tinharé and Boipeba).
Boipeba Island is part of the Tinharé-Boipeba Environmental Protection Area -APA (created by State Decree n° 1.240, of 05/06/1992) and is located approximately 500 m off the southern coast of Bahia state near Camamu Bay (Rio dos Patos).There are also fringe reefs in the area bordering the islands (that remain submerged during the syzygy low tides), shallow reefs at depths between 5 and 10 m, as well as deep reefs at depths from 10 to 20 m (Kikuchi et al. 2008).Kikuchi et al. (2008) recorded the presence of nine coral species and one hydrocoral species on the reefs in the Tinharé-Boipeba APA and Camamu during a visual census using AGRRA (Ginsburg et al. 1998) and PETRORISCO (Dutra and Kikuchi 2003) protocols.The endemic species Mussismilia hispida Verrill, 1902, Mussismilia braziliensis Verrill, 1867, Mussismilia hartti Verrill, 1868, Favia gravida Verrill, 1868, and Siderastrea stellata Verrill, 1868, and the hydrocoral Millepora alcicornis L., 1758 are common elements of the reef fauna in the area.According to Kikuchi et al. (2008), the corals on this reef area grow in pools and canals in association with large numbers of organisms that constitute the reef communities, such as fish, crustaceans, mollusks, segmented worms, etc., and large quantities of algae (coralline, filamentous, and fleshy algae).Kikuchi et al.Wynne (2011) as Hincksia mitchelliae (Harv.)P.C.Silva, but was considered a synonym by Kim (2010).The taxon author names follow Brummitt and Powell (1992).The voucher specimens were deposited in the Herbarium of the Universidade Estadual de Feira de Santana (HUEFS), Bahia state, Brazil.
The order Bryopsidales (with five families) and the (2008) pointed out the importance of green algae along the reefs at Tinharé-Boipeba and Camamu, as they cover approximately 80% of the shallow reef areas there.
Studies of the structures of phytobenthic communities have been used to evaluate environmental impacts on marine environments.According to Oliveira et al. (1999), the biodiversity of marine organisms is correlated to a certain degree with algal community diversityand this diversity increases ecosystem stability -as the presence of greater numbers of functionally equivalent species with different levels of tolerance to environmental factors make these systems better able to resist environmental impacts (including alterations caused by anthropogenic activities).
The aim of the present study was to undertake a taxonomic survey of the phytobenthos at Boipeba Island, Bahia state and confirm the occurrence of Nitophyllum punctatum (Stackh. in With.)Grev.along the Brazilian coast, based on its morphological and reproductive features.
Sampling was undertaken at random during three different periods (July 2007 andMarch andDecember 2012) in the intertidal region of the coastal reefs on the four beaches and in the Bainema mangrove swamp; the specimens were removed with the aid of spatulas and held in labeled plastic bags until processed.
The specimens were fixed and preserved in 4% formaldehyde (using seawater) and subsequently identified with the aid of both a stereomicroscope and a light microscope.The taxonomic arrangement used follows Wynne (2011), with the exception of Feldmannia families Caulerpaceae (eight taxa) and Cladophoraceae (seven taxa) were the richest Chlorophyta taxa at Ponta dos Castelhanos Beach.Among the Heterokontophyta/ Phaeophyceae, the family Dictyotaceae (Dictyotales) stood out with 10 taxa.The most expressive order of the Rhodophyta was Ceramiales, with 23 taxa (57% of which belonged to the family Rhodomelaceae).
Bainema Beach demonstrated a flora comparable to that of Ponta dos Castelhanos, although exclusive taxa were collected at the former that had only occasionally been reported for the coast of Bahia, such as Trichogloea Among the drift specimens on Ponta dos Castelhanos Beach, we were able to confirm the presence of Nitophyllum punctatum for the coast of Bahia state.Torrano-Silva and Oliveira (2013) had provisionally listed this taxon for the region of the Abrolhos Archipelago (off the coast of southern Bahia), but had not encountered  Continued plants with spermatangial or tetrasporangial sori that could confirm their identification.
The specimens of N. punctatum collected at Boipeba Island had thallus blades up to 10 cm tall with delicate appearances, light-red to almost transparent, and composed of repeatedly bifurcating strips that decreased in width toward the terminal portions of the thallus, becoming wedge-shaped; thallus without a central vein, with smooth and undulating edges.Lamina monostromatic, 3-4 cells thick in the basal portion, composed of elongated and polygonal cells, 80-100 µm × 30-50 µm, diminishing in size towards the margins and united by numerous pit-connections; chloroplasts discoid, numerous.Reproductive structures spread along the lamina, except at the base; cystocarps hemispherical, developing on both sides of the lamina, 500-900 µm in diameter, with smooth pericarp and projected ostiole; tetrasporangial sori elliptical to circular, prominent, distributed along the entire thallus on both sides of the lamina, with spherical tetrahedral tetrasporangia 100-160 µm in   diameter (Figure 3).The material examined demonstrated characteristics similar to those described by Maggs and Hommersand (1993) for the British Isles and by Torrano-Silva and Oliveira (2013) for the Abrolhos Archipelago.Two other species of Nitophyllum Grev.have been cited in literature (Moura et al. 2014b) for the Brazilian coast: N. wilksoniae Collins & Herv.(reported for the coasts of Bahia, Espírito Santo, and São Paulo) and N. adhaerens M.J.Wynne (reported for Espírito Santo, Rio de Janeiro, São Paulo, and Santa Catarina).The characteristics that separate the species are listed in Table 2.
The present work added 150 taxa to marine flora the Boipeba Island, including N. punctatum, and confirmed its occurrence along the Bahian coast.
This survey of the phytobenthic biodiversity of Boipeba Island was undertaken to increase our knowledge of the insular marine flora and reef communities that compose the rich natural ecosystems along the coast of Bahia state, Brazil.

Figure 1 .
Figure 1.Map of Boipeba Island on the southern coast of Bahia state, Brazil, with highlighting to the beaches studied 1 -Ponta dos Castelhanos, 2 -Bainema, 3 -Moreré, 4 -Tassimirim (adapted from the map of the Tinharé-Boipeba APA and the roadmap of Bahia state).

Figure 2 .
Figure 2. Distributions of the orders of phytobenthos found at Boipeba Island, Bahia state, Brazil.

Figure 3 .
Figure 3. Nithophyllum pzunctatatum (Stackh.)Grev. A. Tetrasporic plant.B. Detail of the sori of the tetrasporangia distributed on the bifurcated lamina; note the undulating margin.C. Female plant.D. Cystocarps.E. Detail of a cystocarp, with ostiole prominent in lateral view.F. Surface view of thallus cells with pit-connections.G. Margin of the smooth lamina.H. Transversal section of the monostromatic lamina.I. Tetrasporangial sorus in surface view.J. Transversal section of a tetrasporangial sorus.K. Detail of the tetrahedral tetrasporangia.

Table 2 .
Comparisons of the vegetative and reproductive structures of Nitophyllum punctatum, N. adhaerens, N. wilksoniae, and Haraldiophyllum bonnemaisonii.ND = no data available