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(1)Phytotaxa 184 (4): 208–222 www.mapress.com/phytotaxa/ Copyright © 2014 Magnolia Press. ISSN 1179-3155 (print edition). Article. PHYTOTAXA. ISSN 1179-3163 (online edition). http://dx.doi.org/10.11646/phytotaxa.184.4.2. Aulacoseira veraluciae sp. nov. (Coscinodiscophyceae, Aulacoseiraceae): a common freshwater diatom from Brazil PRISCILA IZABEL TREMARIN1*, THELMA ALVIM VEIGA LUDWIG2 & LEZILDA CARVALHO TORGAN3 Programa de Pós-Graduação. Universidade Federal do Rio Grande do Sul, Departamento de Botânica. Avenida Bento Gonçalves, 9500, prédio 43433, 91501-970, Porto Alegre, Rio Grande do Sul, Brasil. 2 Universidade Federal do Paraná, Departamento de Botânica, C.P. 19031, 81531-980, Curitiba, Paraná, Brasil. 3 Museu de Ciências Naturais, Fundação Zoobotânica, C.P. 1188, 90001-970, Porto Alegre, Rio Grande do Sul, Brasil. Corresponding author: ptremarin@gmail.com 1. Abstract Examination of samples from different aquatic environments from Brazil revealed the presence of a new Aulacoseira species. Aulacoseira veraluciae Tremarin, Torgan & T. Ludwig is described and illustrated with light and scanning electron microscopy, and its morphology compared with that of similar species, such as A. muzzanensis (Meister) Krammer, A. granulata (Ehrenberg) Simonsen and A. agassizii (Ostenfeld) Simonsen. The new species is characterized mainly by the straight pervalvar rows of areolae, morphology of the linking spines, shape and position of the rimoportulae on the valve mantle, deepness and thickness of the ringleiste. Key words: Aulacoseira veraluciae, centric diatom, new species, plankton, ultrastructure. Introduction Aulacoseira Thwaites (1848: 167) is widely distributed in continental aquatic environments and constitutes an important part of diatom assemblages. This genus has been extensively studied with material from different regions of the world (e.g. Krammer 1991a, b, Krammer & Lange-Bertalot 1991, Siver & Kling 1997, Houk 2003, Houk & Klee 2007, Usoltseva & Likhoshway 2007, Potapova et al. 2008, Genkal & Kharitonov 2009, Manoylov et al. 2009, Buczkó et al. 2010). In the last decades, several new species have been proposed for Aulacoseira from North of America, Europe, Japan, Russia and subantartic (e.g. Camburn & Charles 2000, Houk et al. 2007, Genkal & Kulikovskiy 2008, English & Potapova 2009, Pearce et al. 2010, Tanaka et al. 2010, Usoltseva & Tsoy 2010, Siver & Hamilton 2011, Van de Vijver 2012, Kociolek et al. 2014). In Brazil, Aulacoseira species were commonly identified based on international research, especially of temperate regions. However, a recent review of the species that occur in the country was made by Tremarin et al. (2011, 2012, 2013a, b, 2014), revealing six new Aulacoseira species and, rectifying some mistaken identifications realized only using LM. This fact emphasizes the importance of a more accurate analysis of the diatom species from tropical and subtropical regions, especially under scanning electron microscopy, to perform a more precise identification. This study aims to propose a new Aulacoseira species that was found in samples from different regions of Brazil and it also describes and compares its morphology with that of similar species.. Material and methods The new Aulacoseira species was found in 77 samples of the 286 analyzed materials collected in rivers, lakes, ponds and reservoirs of Brazil (Table 1, Figure 1). The samples were obtained with a plankton net (25 μm mesh size) and fixed with Transeau solution (Bicudo & Menezes 2006) or with polyethylene bottom and fixed by acetic Lugol (1%) (Bicudo & Menezes 2006). The organic material was removed with KMnO4 and HCl according to the method of 208. Accepted by Patrick Kociolek: 10 Oct. 2014; published: 7 Nov. 2014.

(2) Simonsen (1974) modified by Moreira-Filho & Valente-Moreira (1981). Diatoms were mounted in Naphrax® (R.I. = 1.74) and examined under an Olympus BX40 light microscope (LM). Images were obtained with Olympus DP71 digital camera. A subsample of the oxidized material was placed on aluminum stubs and was sputter-coated with gold at 1 kV for 5 minutes in a Balzers Union SCD 030 sputter coater. Scanning electron microscopy (SEM) observations were made with a JEOL JSM 6360LV, operated at 15 kV at a working distance of 8 mm. The studied slides and samples were deposited in the Herbarium of the Universidade Federal do Paraná (UPCB), Herbarium Prof. Dr. Alarich R. H. Schultz (HAS), Herbarium of the Universidade Federal de Goiás (UFG), Herbarium of Instituto de Botânica de São Paulo (SP), Brazil; and The Natural History Museum (BM), England. Terminology used follows that of Round et al. (1990), Siver & Kling (1997) and Houk (2003).. FIGURE 1. Location of the sampling sites of Aulacoseira veraluciae on different Brazilian geographic regions.. AULACOSEIRA VERALUCIAE SP. NOV.. Phytotaxa 184 (4) © 2014 Magnolia Press • 209.

(3) 210 • Phytotaxa 184 (4) © 2014 Magnolia Press. TREMARIN ET AL.. Codajás Pauini Coari Anamã Coari Manaus Manaus Curaçá Curaçá Britânia. Acará lake. Purus river. Urucú river. Anamã lake. Coarizão lake. Solimões river. Janauari lake. São Francisco river. São Francisco river. Tigres lake. Viana. Codajás. Piorini river. lake near to Cajari. Itacoatiara. Madeira river. Britânia. Codajás. Badajós lake. Vermelho river. Piaçabuçu. Municipality. São Francisco river. Sites. Museum (BM), England.. Maranhão. Goiás. Goiás. Bahia. Bahia. Amazonas. Amazonas. Amazonas. Amazonas. Amazonas. Amazonas. Amazonas. Amazonas. Amazonas. Amazonas. Alagoas. State. 29.VII.2004. VIII.2004. 2004. 15.V.2004. 17.V.2004. 04.XII.2008. 04.XII.2008. 04.XII.2008. 04.XII.2008. 04.XII.2008. 12.X.2004. 18.IX.2004. 18.IX.2004. 21.X.2004. 18.IX.2004. 22.V.2004. Date. …… continued on the next page. slide 6340. UFG 29905. UFG 29865. slide 6296. slide 6293. UPCB 72513. UPCB 72511. UPCB 72508. UPCB 72506. UPCB 72504. slide 6287. slide 6272. slide 6271. slide 6270. slide 6268. slide 6298. Material number. Schultz (slide and HAS), Rio Grande do Sul, Herbarium of the Universidade Federal de Goiás (UFG), Instituto de Botânica (SP), São Paulo, Brazil; and The Natural History. TABLE 1. Data of the sampling sites of Aulacoseira veraluciae and the material number at the Herbarium of the Universidade Federal do Paraná (UPCB), Herbarium Alarich.

(4) AULACOSEIRA VERALUCIAE SP. NOV.. Phytotaxa 184 (4) © 2014 Magnolia Press • 211 Barcarena. Itupanema beach Belém. Belém. Água Preta lake. Farol beach. Belém. Barcarena. Moju river. Murutucu island. São Félix do Xingu. Xingu river. Altamira. Iriri river. São Félix do Xingu. Altamira. Xingu river. Xingu river. Belterra. Tapajós river. Altamira. Maracaju. dam on a farm. Curuá river. Nossa Senhora do Livramento. Barão do Melgaço. Sinhá Mariana lake. Coqueiro lake. Aquidauana. Pantaneira lagoon. Poconé. São Félix do Araguaia. Araguaia river. Gaíba lake. Pium. Municipality. Araguaia river. Sites. TABLE 1. (Continued). Pará. Pará. Pará. Pará. Pará. Pará. Pará. Pará. Pará. Pará. Pará. Mato Grosso do Sul. Mato Grosso. Mato Grosso. Mato Grosso. Mato Grosso. Mato Grosso. Mato Grosso. State. 26.IX.2008. 31.X.2005. 29.VIII.2007. 16.VII.2003. 04.IX.2004. 21.VII.2004. 21.VII.2004. 20.VIII.2004. 20.VIII.2004. 27.VIII.2004. 22.VII.2004. 28.XII.2003. IV.2002 to V.2003. IX.1997 to VIII.1998. 27.XII.2003. 27.XII.2003. 19.VI.2004. 21.VI.2004. Date. …… continued on the next page. UPCB 72272. UPCB 72271. UPCB 72036. UPCB 58045. slide 6337. slide 6289. slide 6284. slide 6281. slide 6280. slide 6273. slide 6267. slide 6323. UPCB 67020. UPCB 67019. slide 6322. slide 6307. slide 6303. slide 6300. Material number.

(5) 212 • Phytotaxa 184 (4) © 2014 Magnolia Press. TREMARIN ET AL.. Belém de São Francisco Belém de São Francisco. São Francisco river. São Francisco river. Santana do Matos Três Cachoeiras. Rio da Pedra dam. Itapeva lake. Floresta. Ponta Grossa. São Jorge reservoir. Pajeú river. Ponta Grossa. Pinhão. Foz do Areia reservoir. Pitangui reservoir. Prudentópolis. Rio dos Patos reservoir. Itapejara d’Oeste. Santarém. Açai lake. Chopim reservoir. Santarém. Sant’Anna lake. Antonina. Santarém. Grande de Curuai lake. Capivari reservoir. Itupiranga. Tocantins river. Juruti. Barcarena. Caripi beach. Paranapitinga lake. Belém. Municipality. Guamá river. Sites. TABLE 1. (Continued). Rio Grande do Sul. Rio Grande do Norte. Pernambuco. Pernambuco. Pernambuco. Paraná. Paraná. Paraná. Paraná. Paraná. Paraná. Pará. Pará. Pará. Pará. Pará. Pará. Pará. State. 07.II.2004. 2008. 17.V.2004. 17.V.2004. 17.V.2004. 2011. 2011. 18.X.2007. 23.VIII.2007. 29.VI.2007. 01.VIII.2007. 16.III.2004. 17.III.2004. 18.III.2004. 19.III.2005. 15.V.2002. 29.II.2008. 31.VIII.2009. Date. …… continued on the next page. slide 6312. UPCB 72281. slide 6344. slide 6291. slide 6290. UPCB 72254. UPCB 72249. UPCB 59531. UPCB 59522. UPCB 59517. UPCB 59516. UFG 46266. UFG 46265. UFG 46264. UFG 46262. UPCB 72277. UPCB 72275. UPCB 72273. Material number.

(6) AULACOSEIRA VERALUCIAE SP. NOV.. Phytotaxa 184 (4) © 2014 Magnolia Press • 213. Santa Vitória do Palmar. Mangueira lake. Tapes and Mostardas Tapes and Mostardas Tapes and Mostardas. Patos lagoon. Patos lagoon. Patos lagoon. Barra Bonita. Piraju. Jurimirim reservoir. Tietê river. Fartura. Chavantes reservoir. Salto Grande. Tapes and Mostardas. Patos lagoon. Santo Grande reservoir. Porto Alegre. Guaíba lake. Santa Vitória das Palmas. Palmares do Sul. Casamento lake. river near to Mirim lake. Rosário do Sul. dam in the Santa Maria river. Uruguaiana. Santa Vitória do Palmar. Mirim lake. Touro Passo stream. Santa Vitória do Palmar. Pacheco lake. Rosário do Sul. Uruguaiana. Uruguai river. Santa Maria river. Municipality. Sites. TABLE 1. (Continued). São Paulo. São Paulo. São Paulo. São Paulo. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. Rio Grande do Sul. State. 02.I.1991. 22.I.1992. X.2005 to VII.2006. X.2005 to VII.2006. IV.1988. 07.I.1988. XII.1987. 08.XII.1987. 07.II.2004. 06.II.2004. 04.II.2004. 20.I.2004. 18.I.2004. 06.II.2004. 06.II.2004. 06.II.2004. 20.I.2004. 16.I.2004. Date. …… continued on the next page. SP 255742. SP 239140. UPCB 72515. UPCB 72288. HAS 16968. UPCB 76037, BM 101711. HAS 16894. HAS 16893. slide 6330. slide 6329. slide 6327. slide 6326. slide 6325. slide 6321. slide 6320. slide 6319. slide 6317. slide 6314. Material number.

(7) 214 • Phytotaxa 184 (4) © 2014 Magnolia Press. TREMARIN ET AL.. Bernardo Sayão Pium Pium. Araguaia river. Javaés river. Avaré. Jurimirim reservoir. Araguaia river. Avaré. Municipality. Jurimirim reservoir. Sites. TABLE 1. (Continued). Tocantins. Tocantins. Tocantins. São Paulo. São Paulo. State. 21.VI.2004. 21.VI.2004. 22.VII.2004. 10.IX.1991. 10.IX.1991. Date. slide 6299. slide 6295. slide 6288. SP 255773. SP 255759. Material number.

(8) Results Aulacoseira veraluciae Tremarin, Torgan & T. Ludwig, sp. nov. (Figs 2‒35) Holotype:—UPCB 76037, Diatom Collection of the Herbarium of Universidade Federal do Paraná, Brazil, illustrated here in Fig. 21. Isotype:—BM 101711 (The Natural History Museum, England).. FIGURES 2–22. Aulacoseira veraluciae, LM. Scale: 10 μm. Figs 2, 3. Initial cells. Figs 4, 5. Valve view of the separation cells. Figs 6, 7. Valve view of the linking cells. Fig. 8. View of the cell lumen showing the ringleiste. Figs 9‒22. Aspect of the chains.. AULACOSEIRA VERALUCIAE SP. NOV.. Phytotaxa 184 (4) © 2014 Magnolia Press • 215.

(9) FIGURES 23–29. Aulacoseira veraluciae, SEM, external view. Scales: 5 μm (Figs 23, 29), 2 μm (Figs 24‒28). Fig. 23. Overview of the valve showing the separation spines. Fig. 24. Valve face of the separation cell. Fig. 25. Valve face of the linking cell. Figs 26, 27. Detail of the linking spines. Fig. 28. Detail of the mantle areolae occluded by velum. Fig. 29. Mantle of the linking valves and location of external rimoportulae openings (arrows).. 216 • Phytotaxa 184 (4) © 2014 Magnolia Press. TREMARIN ET AL..

(10) FIGURES 30–35. Aulacoseira veraluciae, SEM. Scales: 2 μm (Figs 30, 31, 34), 1 μm (Figs 32, 33, 35). Figs 30, 31. External rimoportulae openings (arrows) in the separation and linking valves, respectively. Fig. 32. Internal rimoportula opening (arrow) near the valve face/ mantle junction in the separation valve. Fig. 33. Internal rimoportulae openings (arrows) on the ringleist. Fig. 34. Detail of ringleiste. Fig. 35. Aspect of the girdle bands. Note the fimbriate valvocopula (arrow).. AULACOSEIRA VERALUCIAE SP. NOV.. Phytotaxa 184 (4) © 2014 Magnolia Press • 217.

(11) Type locality:—BRAZIL. State of Rio Grande do Sul, Tapes and Mostardas municipalities, Patos lake, 30º23’S/ 50º41’W to 32º07’S/52º12’W, phytoplankton, collected from 07 January 1988 by L.C. Torgan. Etymology:—The new species is named in honor of Dr. Vera Lúcia de Moraes Huszar of National Museum, Rio de Janeiro Federal University, for her dedication to phytoplankton research. Description:—Cells solitary or joined by short spines to form short or long chains, straight or slightly curved. Valve diameter 3–15 μm, mantle height 4–12 μm. Mantle height/diameter ratio 0.35–2.01. Separation valves with face flat, totally or partially covered by areolae and mantle with deep longitudinal depressions formed by the spine insertion of the adjacent cell. Separation spines attenuate and long (ca. 3‒8 μm in length), one to five per valve, intercalate by other smaller and conical spines, one spine for every two interstriae. Linking valves with a flat face, perforated by marginal areolae that extend into the mantle through the marginal spines. Linking spines short, broadly spathulate with smooth edge, one spine for every two interstriae. Valve mantle usually ornamented by small knobs. Collum narrow, height 0.8‒1.1 μm. Pervalvar rows of areolae straight, 10‒16 in 10 μm. Areolae triangular close to marginal spines become rounded in the middle region of the mantle and elongate near the collum, 10‒15 in 10 μm, occluded by cribra. Ringleiste deep and thick, width1.6‒2.3 μm, protruding into the cell with reinforced rim. One to three rimoportulae above the inner side of the ringleiste. Other rimoportulae near the valve face/mantle junction in the separation and linking valves. External opening of rimoportulae associated with an areola, and not visible in LM. Internal opening of rimoportulae elongate and without stalk. Girdle bands with prominent ligula and finely perforated by round porous, ca. 10‒13 in 1 μm. Valvocopulae fimbriate. Auxospore with 12‒15 μm diameter.. Discussion The frustules with coarser areolation pattern and the long separation spines of Aulacoseira veraluciae caused misidentifications with other known species of the genus, as A. muzzanensis (Meister) Krammer (1991: 98), A. granulata (Ehrenberg) Simonsen (1979: 79) var. granulata and A. agassizii (Ostenfeld) Simonsen (1979: 56) var. agassizii and A. agassizii var. malayensis (Hustedt) Simonsen (1979: 56). However, the typical shape of linking spines, the straight pattern of the pervalvar rows of areolae, position and shape of the rimoportulae on the deep ringleist are the most obvious features that separate A. veraluciae from similar taxa. The linking spines of A. veraluciae are broadly spathulate and occur at the union of every two interstriae (see Figs 26, 27), unlike A. granulata which has a spathulate spine at the top of a single interstria (Table 2). When observing A. veraluciae under LM, larger areolae are well observed between spines at the connection region of the sibling valves. These areolae are most evident with increased frustule diameter (see Figs 14‒22). However, spine morphology of Aulacoseira veraluciae can only be visualized with more precision by SEM. The long chains of A. veraluciae and the terminal valves with long and attenuate separation spines resemble A. granulata and A. muzzanensis. The separation valves of A. granulata and A. muzzanensis have straight pervalvar rows of areolae in the mantle, while in the connection valves the areolae are arranged in oblique rows (Krammer 1991b, Krammer & Lange-Bertalot 1991, Tremarin et al. 2012). In addition, the morphology of linking spines, narrowness of the ringleiste, shape and position of rimoportulae of A. granulata and A. muzzanensis are other features that allow distinction from A. veraluciae (Table 2). Aulacoseira agassizii var. agassizii and A. agassizii var. malayensis have a thick ringleiste, long separation spines and round areolae on the mantle that resemble those of A. veraluciae (Ostenfeld 1908, Huber-Pestalozzi 1942, Hustedt 1942). However, observations of the lectotype of Ostenfeld´s A. agassizii var. agassizii illustrated by Tremarin et al. (2012) show it is possible to note the wider valves, oblique pervalvar rows of areolae in the connection valves, stalked rimoportulae distributed in the middle region of the mantle, and a linking spine per interstria with irregular margins (Table 2). Aulacoseira agassizii var. malayensis differs from A. veraluciae by having larger diameter and higher density of pervalvar rows of areolae, wider ringleiste and smaller rimoportulae near the ringleiste with indistinct external opening of the areola (Table 2) (Hustedt 1942, Tremarin et al. 2012). Exemplars quite similar to Aulacoseira veraluciae were illustrated by Metzeltin et al. (2005) as A. muzzanensis (see Plate 1, Figs. 5, 8‒10) and A. ambigua (Grunow in Van Heurck) Simonsen (1979: 56) (see Plate 1, Figs. 11‒13) from Uruguay. The new species was also record from Brazil by Bicudo et al. (1993, 1995) as A. muzzanensis from Rosana reservoir, State of São Paulo, and from Poconé Pantanal, State of Mato Grosso; by Ludwig et al. (2004) as A. muzzanensis from Taim wetland, State of Rio Grande do Sul; by Menezes et al. (2012) as A. granulata from Piraquê channel (first exemplar of the Fig. 13), State of Rio de Janeiro; and by Hermany et al. (2013) as Aulacoseira aff. agassizii 218 • Phytotaxa 184 (4) © 2014 Magnolia Press. TREMARIN ET AL..

(12) AULACOSEIRA VERALUCIAE SP. NOV.. Phytotaxa 184 (4) © 2014 Magnolia Press • 219. 2$/ 1 3(.- -#+(-*(-&5 +5$2. 5 +5$% "$ , -3+$)4-"3(.-.%. 1(-&+$(23$ -#.3'$1(-3'$. $+.-& 3$# : .-3'$. #$$/ :

(13) 9,. /$1

(14) (-3$1231( $. 2,..3', 1&(-2. 3'$1(-&+$(23$. ".(+$#.-$1$&4+ 11.6-$ 1. 2' ++.6" 9,. /$1(-3$1231( . 2/ 3'4+ 3$. 33$-4 3$. :1.62.%, 1&(- + 1$.+ $.

(15) 9,. 1.6(-3'$5 +5$, -3+$. /$#4-"4+ 3$.-$(11$&4+ 1. #$$/

(16) : 9,. /$1(-3$1231( . , 1&(-2 -# 33$-4 3$ /("$2. 2/ 3'4+ 3$6(3'(11$&4+ 1. 33$-4 3$. 3.3 ++7.1/ 13( ++7 1$.+ 3$.

(17) : 9,. 3'$5 +5$, -3+$. 2$22(+$.-$(11$&4+ 11.6(-. 5$17#$$/ : 9,. !2$-3. 33$-4 3$. 3.3 ++7 1$.+ 3$. 9,. 1.4-#. : 9,. 231 (&'3. : . :. malayensis5,8. A. agassizii var.. )4-"3(.-.%2$/ 1 3(.-5 +5$2. -# (-3'$5 +5$% "$ , -3+$. ".(+$# -$ 13'$1(-&+$(23$. 2' ++.66(#3'-.31$".1#. /$1(-3$1231( . 2/ 3'4+ 3$!(#$-3 3$. 33$-4 3$. 3.3 ++7.1/ 13( ++7 1$.+ 3$. :

(18) 9,. 1.4-#3.204 1$. : 9,. 231 (&'33..!+(04$. :

(19) . : . granulata4,9,10,11. A. granulata var.. # 3 ,$ 241$#.%3'$(++4231 3(.-2. .3 /.5 -&+(2'

(20). . 11. 3'(2234#7 2$(23$1

(21) 31 ,,$1 ! 4423$#3 51$, 1(-et al.

(22)

(23) 623$-%$+# 74!$1$23 +.88(

(24) 8423$#3

(25) 9(5$1+(-& 10.4*

(26). . 1. (,./.134+ $. (-&+$(23. (-*(-&2/(-$2. 33$-4 3$. $/ 1 3(.-2/(-$2. 6(#$+72/ 3'4+ 3$6(3'. 3.3 ++7.1/ 13( ++7 1$.+ 3$. : 9,. 1.4-#. 204 1$. 1.4-#. $/ 1 3(.-5 +5$2. 1$.+ $. :

(27) 9,. : 9,. 231 (&'33..!+(04$. : .

(28) : . A. agassizii var. agassizii5,6,7. : 9,. 231 (&'33..!+(04$. 231 (&'3. $15 +5 11.62.% 1$.+ $. :. :

(29) . -3+$'$(&'39,. :

(30) . A. muzzanensis2,3,4,5. : . A. veraluciae1. ( ,$3$19,. . TABLE 2. Morphological and metric variation of Aulacoseira veraluciae and related species..

(31) in paleoecological study from a lacustrine system, State of Rio Grande do Sul. Other records of A. muzzanensis, A. agassizii and A. agassizii var. malayensis from Brazil belong to A. brasiliensis Tremarin, Torgan & Ludwig (2012: 172‒173) or were not illustrated (e.g. Nogueira & Leandro-Rodrigues 1999, Torgan et al. 1999, Nogueira et al. 2008), making it difficult to identify these materials. Aulacoseira veraluciae occurred in oligotrophic to eutrophic environments, such as Chavantes and Salto Grande reservoirs, respectively (Pagioro et al. 2005, Nogueira et al. 2006). Wide morphological and metric variation of the new species, including formation of auxospore and initial cells, was found in the samples of the Patos lagoon during the summer of 1988.. Acknowledgements The study was found by a doctoral grant from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) to the first author and by scientific productivity grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) to the others authors. We thank to the staff of the Electron Microscopy Center of Universidade Federal do Paraná for technical assistance. We also thank to Dr. Vera Huszar (UFRJ), Dr. Ina Nogueira (UFG), Dr. Simoni Loverde-Oliveira (UFMT), Dr. Marcos Nogueira (UNESP) and Dr. Rosildo Paiva (UFPA) for taking samples for this study.. References Bicudo, C.E.M. & Menezes, M. (2006) Gêneros de algas de águas continentais do Brasil. Rima, São Paulo, 498 pp. Buczkó, K., Ognjanova-Rumenova, N. & Magyari, E. (2010) Taxonomy, morphology and distribution of some Aulacoseira taxa in glacial lakes in the south Carpathian region. Polish Botanical Journal 55(1): 149–163. Camburn, K.E. & Charles, D.F. (2000) Diatoms of Low-Alkalinity Lakes in the Northeastern United States. Academy of Natural Sciences of Philadelphia 18: 1‒152. English, J. & Potapova, M. (2010) Aulacoseira granulata. In: Diatoms of the United States. Retrieved October 31, 2011, from http:// westerndiatoms.colorado.edu/taxa/species/aulacoseira_granulata_angustissima Genkal, S.I. & Kharitonov, V.G. (2009) Morphological variability of several species of the genus Aulacoseira Thw. (Bacillariophyta). Algologia 19(1): 3‒10. Genkal, S.I. & Kulikovskiy, M.S. (2008) New centric diatom species (Bacillariophyta) from the Polistovo-Lowatsky sphagnous tract (Rdeisk State Nature Preserve). Botanicheskii Zhurnal 93(5): 771‒775. Hermany, G., Souza, P.A. & Torgan, L.C. (2013) Paleoecologia do sistema Pinguela-Palmital-Malvas, Holoceno da Bacia de Pelotas, RS, Brasil: uma abordagem focada na utilização de análises multivariadas para obtenção de diatomáceas descritoras. Pesquisas em Geociências 40(1): 31–49. Houk, V. (2003) Atlas of freshwater centric diatoms with a brief key and descriptions. Part I. Melosiraceae, Orthoseiraceae, Paraliaceae and Aulacoseiraceae. In: Poulícková, A. (Ed.). Czech Phycology Supplement, Olomouc: Czech Republic, 1: 1‒111. Houk, V. & Klee, R. (2007) Atlas of freshwater centric diatoms with a brief key and descriptions Part II. Melosiraceae and Aulacoseiraceae (Supplement to Part I). Fottea 7(2): 85‒255. Houk, V., Klee, R. & Passauer, U. (2007) Observations on taxa of Melosira sensu lato among the slides from the Grunow diatom collection in Vienna (Austria). Part 1. Diatom Research 22(1): 57‒80. http://dx.doi.org/10.1080/0269249x.2007.9705695 Huber-Pestalozzi, G. (1942) Diatomeen. In: Thienimann, A. (Ed.) Das Phytoplankton des Susswassers, Systematik und Biologie, Stuttgart, E. Schweizerbartsche Verlagsbuchhandlung 2: 367–549. Hustedt, F. (1930) Bacillariophyta (Diatomeae). In: Pascher, A. (Ed.) Die Süsswasser-Flora Mitteleuropas. Vol. 10. G.Fischer, Jena, pp. 1–466. Hustedt, F. (1942) Süßwasser-Diatomeen des indomalayischen Archipels und der Hawaii-Inslen. Internationale Revue der gesamten Hydrobiologie und Hydrographie 42(1/3): 1‒252. Kociolek, J.P., Laslandes, B., Bennet, D., Thomas, E., Brady, M. & Graeff, C. (2014) Diatoms of the United States. I. Taxonomy, Ultrastructure and Descriptions of Fifty New Species and Other Rarely Reported Taxa from Lake Sediments in the western U.S.A. Bibliotheca Diatomologica 61: 1‒188. Krammer, K. (1991a) Morphology and taxonomy of some taxa in the genus Aulacoseira Thwaites (Bacillariophyceae). I. Aulacoseira. 220 • Phytotaxa 184 (4) © 2014 Magnolia Press. TREMARIN ET AL..

(32) distans and similar taxa. Nova Hedwigia 52(1‒2): 89‒112. Krammer, K. (1991b) Morphology and taxonomy in some taxa of the genus Aulacoseira Thwaites (Bacillariophyceae). II. Taxa in the A. granulata-, italica- and lirata-groups. Nova Hedwigia 53(3‒4): 477‒496. Krammer, K. & Lange-Bertalot, H. (1991) Bacillariophyceae, Teil. 3: Centrales, Fragilariaceae, Eunotiaceae. Süsswasserflora Mitteleuropa 2/3: 1‒576. Manoylov, K.M., Ognjanova-Rumenova, N. & Stevenson, R.J. (2009) Morphotype variations in subfossil diatom species of Aulacoseira in 24 Michigan Lakes, USA. Acta Botanica Croatica 68(2): 401–419. Meister, F. (1912) Die Kieselalgen der Schweiz. Beiträge zur Kryptogamenflora der Schweiz. 4(1): 1‒254. Menezes, M., Branco, S., Guimarães, R.R., Sousa, V.L.M., Alves-de-Souza, C., Silva, W.J., Domingos, P. & Gômara, G. (2012) Composição florística de cianobactérias e microalgas do canal do Piraquê, lagoa Rodrigo de Freitas, sudeste do Brasil. Oecologia Australis 16(3): 421–440. http://dx.doi.org/10.4257/oeco.2012.1603.08 Metzeltin, D., Lange-Bertalot, H. & García-Rodriguez, F. (2005) Diatoms of Uruguay - Compared with other taxa from South America and elsewhere. In: Lange-Bertalot, H. (Ed.) Iconographia Diatomologica, Vol. 15. Koeltz Scientific Books, Koenigstein, 736 pp. Moreira-Filho, H. & Valente-Moreira, I.M. (1981) Avaliação taxonômica e ecológica das diatomáceas (Bacillariophyceae) epífitas em algas pluricelulares obtidas nos litorais dos estados do Paraná, Santa Catarina e São Paulo. Boletim do Museu Botânico Municipal 47: 1‒17. Nogueira, M.G., Jorcin, A., Vianna, N.C. & Britto, Y.C. (2006) Reservatórios em cascata e os efeitos na limnologia e organização das comunidades bióticas (fitoplâncton, zooplâncton e zoobentos): Um estudo de caso no rio Paranapanema (SP/PR). In: Nogueira, M.G., Henry, R. & Jorcin, A. (Eds.) Ecologia de reservatórios: Impactos potenciais, ações de manejo e sistemas em cascata. São Carlos, Brasil, pp. 83–125. Ostenfeld, C.H. (1908) Notes on the Phytoplankton of Victoria Nyanza, East Africa. Bulletin of the Museum of Comparative Zoology at Harvard College 52(10): 171‒181. Pagioro, T.A., Velho, L.F.M., Lansac-Tôha, F.A., Pereira, D.G. & Nakamura, A.K.S. (2005) Influência do grau de trofia sobre os padrões de abundância de bactérias e protozoários planctônicos em reservatórios do Estado do Paraná. In: Rodrigues, L., Thomaz, S.M., Agostinho, A.A. & Gomes, L.C. (Eds.) Biocenoses em reservatórios: padrões espaciais e temporais, São Carlos, Brazil, pp. 47–56. Pearce, C., Cremer, H. & Wagner-Cremer, F. (2010) Aulacoseira coroniformis sp. nov., a new diatom (Bacillariophyta) species from Highlands Hammock State Park, Florida. Phytotaxa 13: 40–8. Potapova, M. & English, J. (2010) Aulacoseira granulata. In: Diatoms of the United States. Retrieved April 04, 2014, from http:// westerndiatoms.colorado.edu/taxa/species/aulacoseira_granulata Potapova, M.G., Bixby, R.J., Charles, D.F., Edlund, M.B., Enache, M.E., Furey, P., Hamilton, P.B., Lowe, R.L., Manoylov, K.M., Ognjanova-Rumenova, N., Ponader, K.C., Ren, L., Siver, P.A., Spaulding, S.A. & Zalack, J. (2008) Representatives of the genus Aulacoseira Thwaites in NAWQA samples. Eighteenth NAWQA Workshop on Harmonization of Algal Taxonomy, April 27–29, 2007. Report 08‒07. Patrick Center for Environmental Research, The Academy of Natural Sciences, Philadelphia, 56 pp. Round, F.E., Crawford, R.M. & Mann, D.G. (1990) The diatoms: biology and morphology of the genera. Cambridge University Press, New York. 670p. Simonsen, R. (1974) The diatom plankton of the Indian Ocean expedition of the R/V Meteor 64–65. Meteor Forschungsergebnisse, ser. D., 19:1‒107. Simonsen, R. (1979) The diatom system: ideas on phylogeny. Bacillaria 2: 9‒71. Siver, P.A. & Hamilton, P.B. (2011) Diatoms of North America: the freshwater flora of waterbodies on the Atlantic Coastal Plain. In: Lange-Bertalot, H. (Ed.) Iconographia Diatomologica 22: 1–916. Siver, PA & Kling, H (1997) Morphological observations of Aulacoseira using scanning electron microscopy. Canadian Journal of Botany 75: 1807‒1835. http://dx.doi.org/10.1139/b97-894 Tanaka, H. & Nagumo, T. (2010) Aulacoseira satsumaensis, a new Pliocene diatom species with two morphotypes from Kagoshima, Japan. Diatom Research 25(1):163‒174. http://dx.doi.org/10.1080/0269249x.2010.9705836 Tremarin, P.I., Ludwig T.A.V. & Torgan, L.C. (2012) Ultrastructure of Aulacoseira brasiliensis sp. nov. (Coscinodiscophyceae) and comparison with related species. Fottea 12(2): 171–188. Tremarin, P.I., Ludwig T.A.V. & Torgan, L.C. (2014) Four new Aulacoseira species (Coscinodiscophyceae) from Matogrossense Pantanal, Brazil. Diatom Research 69(2): 183‒199. http://dx.doi.org/10.1080/0269249x.2014.880072 Tremarin, P.I., Loverde-Oliveira, S.M., Ludwig, T.A.V. & Torgan, L.C. (2011) Ultrastructure and distribution of Aulacoseira gessneri (Hustedt) Simonsen (Diatomeae). Diatom Research 26(2): 189‒197.. AULACOSEIRA VERALUCIAE SP. NOV.. Phytotaxa 184 (4) © 2014 Magnolia Press • 221.

(33) Tremarin, P.I., Paiva, R.S., Ludwig, T.A.V. & Torgan, L.C. (2013a) Aulacoseira calypsi sp. nov. (Coscinodiscophyceae) from an Amazonian lake, northern Brazil. Phycological Research 61: 292‒298. http://dx.doi.org/10.1111/pre.12031 Tremarin, P.I., Ludwig, T.A.V. & Torgan, L.C. (2013b) Morphological variation and distribution of the freshwater diatom Aulacoseira ambigua (Grunow) Simonsen in Brazilian continental environments. Iheringia, Série Botânia 68(1): 139‒157. Usoltseva, M.V. & Likhoshway, Y.V. (2007) The fine structure of loricae in the species of the genus Aulacoseira Thwaites (Bacillariophyta) from Ob’ River (Russia). Algologia 17, 139–152. Usoltseva, M.V. & Tsoy, I.B. (2010) Elliptical species of the freshwater genus Aulacoseira in Miocene sediments from Yamato Rise (Sea of Japan). Diatom Research 25(2): 397‒415. http://dx.doi.org/10.1080/0269249x.2010.9705859 Van de Vijver, B. (2012) Aulacoseira principissa sp. nov., a new ‘centric’ diatom species from the subAntarctic region. Phytotaxa 52: 33‒42. Thwaites, G.H.K. (1848) Further observations on the Diatomaceae with descriptions of new genera and species. Annals and Magazine of Natural History 1: 161‒172. http://dx.doi.org/10.1080/03745485809496091. 222 • Phytotaxa 184 (4) © 2014 Magnolia Press. TREMARIN ET AL..

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