Bangiopsis subsimplex ( Mont . ) F . Schmitz ( Stylonematales , Rhodophyta ) on the northeastern coast of Brazil 1

We report here the fi rst occurrence of Bangiopsis subsimplex (Mont.) F.Schmitz (Rhodophyta) for the northeastern coast of Brazil. Th e specimen was isolated from a laboratory sample of mollusk shells collected in Baía de Todos os Santos (Bimbarras Island, Brazil) and was held in sterilized seawater (33 UPS) enriched with 25% Provasoli solution. In the American Atlantic region, B. subsimplex presents a northern distribution limit at French Guiana and a southern limit at São Paulo. We conclude that the distribution of B. subsimplex has expanded, since the species was once known only to the southeastern Brazil, specifi cally to São Paulo.


Short Communication
Bangiopsis F.Schmitz (Rhodophyta, Stylonematophyceae) is one of 13 genera in the order Stylonematales (West et al. 2007).Morphologically, species in this genus are characterized by a fl exible, fi lamentous thallus, with the younger portions uniseriate and older portions multiseriate and thicker; ramifi cations, when present, are sparse, subdichotomous to regular, and sometimes have short and uniseriate proliferations on the thallus; the cells are rounded, and have star-shaped chloroplasts with pyrenoids; reproduction occurs by way of monosporangia (Børgesen 1915;Krishnamurthy 1957;West et al. 2005).
Th e genus has a disjunct geographical distribution.A study by Guiry & Guiry (2012) presents sparse records from marine and estuary environments in Japan, the Fiji Islands, Southeast Asia (India, Pakistan, Sri Lanka and Vietnam) and the western Atlantic (Virgin Islands, Cuba, Jamaica, Hispaniola, Guyana, Columbia and Brazil).Th ere are currently two recognized species of Bangiopsis: B. dumontioides V.Krishnam (P.Crouan & H.Crouan in Schramm & Mazé) and B. subsimplex F.Schimtz, both described for the western Atlantic by Wynne (2011).
In Brazil, the genus Bangiopsis was previously known only to the southeastern coast.Creed et al. (2012) reported the occurrence of B. dumontioides for the state of Rio de Janeiro (based on Brasileiro et al. 2009) and B. subsimplex along the coast of the state of São Paulo (based on Joly 1965).However, this work referred only to a single species of Bangiopsis, identifi ed as B. humphreyi (Collins) G.Hamel (= B. dumontioides) and probably represents an erroneous identifi cation of B. subsimplex.In examining the molecular phylogeny of Porphyra species found along the Brazilian coast, Milstein & Oliveira (2005) also sequenced specimens of Bangiopsis species from Cardoso Island, São Paulo (initially identifi ed as Bangia fuscopurpurea (Dillwyn) Lyngb.).However, aft er obtaining small-subunit ribosomal DNA sequences, they concluded that the specimen was in fact B. subsimplex.
Th e present study presents the fi rst record of B. subsimplex for the northeastern coast of Brazil and describes the morphologic characteristics of the specimens encountered.
Th e B. simplex specimens were obtained from mollusk shells collected on Bimbarras Island in the municipality of São Francisco do Conde, which is located in the northern region of Baía de Todos os Santos,Brazil (12º43'29''S;38º38'09"W).Th e shells were transferred to small cultivation fl asks (140 ml baby food jars) containing sterilized seawater (33 UPS) enriched with 25% Provasoli solution (Provasoli 1968).Th e media was renewed every two weeks.The specimens were cultivated in stagnant cultures at 22±1°C under a horizontal bank of cold white fl uorescent lamps (30±5 μmol of photons m −2 s −1 ), on a 12/12-h light/ dark cycle (Bravin et al. 2006).
Th e morphological and anatomical characters of B. subsimplex were analyzed by stereo and light microscopy, with an ocular micrometer and a coupled digital microscope camera.Th e dimensions recorded (diameter and length) were determined by making between 10 and 20 measurements of randomly chosen specimens.
Aft er the analyses, the specimens were deposited in the Herbarium of the Universidade Estadual de Feira de Santana (HUEFS, Feira de Santana State University).B. subsimplex was not common in the study area.It was encountered under in vitro culture conditions, growing on the shells of mollusks that had been collected in sandy/ muddy substrate sites and adhering to the walls of cultivation fl asks in association with Derbesia species.
Among the fi lamentous genera in the order Stylonematales, Bangiopsis is morphologically similar to Purpureofi lum J.A.West, G.C.Zuccarello & J.L.Scott, although the latter is distinguished by having a diminutive thallus (up to 1 mm), unicellular basal system, cells with a multiple-lobed single chloroplast without a pyrenoid and non-mobile spores not formed in packets (West et al. 2005).West et al. (2007) examined partial sequences of smallsubunit RNA and the psbA gene (DNA) and observed that in the resulting consensus tree (maximum-likelihood topology) the genera Bangiopsis and Purpureofi lum grouped together with Rhodaphanes J.A.West, G.C.Zuccarello, J.L.Scott & K.A.West -a genus with a diminutive thallus and which is morphologically similar to Stylonema Reinsch.According to those authors, Rhodaphanes is distinct from Bangiopsis and Purpureofi lum in that its species have cells with one parietal multilobed chloroplast and without a peripheral encircling thylakoid (a feature not seen in any other genus of the class Stylomenatophyceae), as well as cell walls with digeneaside, sorbitol, and trehalose as their principal low molecular weight carbohydrates.
B. subsimplex was proposed by Schmitz (1896) based on Compsopogon subsimplex, a taxon described by Montagne (1850) from material collected by Leprieur in Caiena, French Guiana (Bryant & Irvine 2002).Schmitz categorized the species as a doubtful member of the family Bangiaceae, although Drew (1956) transferred it to the family Stylonemataceae together with other genera of unicellular, fi lamentous or pseudofi lamentous algae.
Th e specimens from Bimbarras Island that were identifi ed as B. subsimplex coincided precisely with the descriptions by Montagne (1850, as Compsopogon subsimplex) and Børgesen (1915).Th e specimens also coincided, in part, with descriptions by Krishnamurthy (1957) and West et al. (2005), although those authors described thalli with ramifi cations -a characteristic not observed in the specimens examined here.
No reproductive structures were observed in the specimens analyzed; however, according to West et al. (2005), B. subsimplex reproduces by way of monospores that migrate through shuffl ing (when tails are absent) or brief movement (when tails are present).Th e spores are formed either independently or in small packets enclosed within a matrix.Th ese spore packets contain 5-20 spores and the cell division patterns give the packets a polyhedral parenchymatous appearance (West et al. 2005).
In the western Atlantic region, the distribution area of B. subsimplex ranges from French Guiana in the north to São Paulo in the south.Th erefore, we are able to conclude that the distribution area of B. subsimplex has grown along the Brazilian coast, as this species was once known only to the southeastern region of the country, specifi cally along the coast of the state of São Paulo (Creed et al. 2012).

Figure 1 .
Figure 1.B. subsimplex (Mont.)F.Schmitz. A. General aspect of the thallus growing on a mollusk shell.B. Filament showing the uniseriate apical region with posterior thickenings.C. Filiform and fl exuous fi lament.D. Apical cell (arrow).E. Subapical cells; note the transversal cell arrangement in the fi lament (arrow).F. Detail of the basal region cells; note the cell with a star-shaped chloroplast (arrow).G. Detail of the apical region cells; note the cells with evident pyrenoids (arrow), seen by interference contrast microscopy.H. Detail of the multiseriate portion of the thallus; note the irregular cell placement.I-J.Short or long uniseriate proliferations originating in the basal region of the thallus.