identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
481087A9E14AFFA5FF1BFBAFFE99FBA0.text	481087A9E14AFFA5FF1BFBAFFE99FBA0.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cosmarium bahianum G. J. P. Ramos, C. E. M. Bicudo & C. W. N. Moura 2017	<div><p>Cosmarium bahianum G.J.P.Ramos, C.E.M.Bicudo &amp; C.W.N.Moura,  sp. nov. (Figs. 1–22)</p><p>Description</p><p>Cells usually slightly longer than broad, with a moderately deep median constriction. Sinus widely open, about rectangular at the apex. Semicells in frontal view elliptic-rhomboid, in apical view elliptic or subtriangular, in lateral view subcircular. Cell wall coarsely punctate. Chloroplast with 1 pyrenoid. Cells provided with a thick, sharply bounded mucilaginous envelope. Zygospore smooth-walled, globose to elliptical. Cell dimensions: length 20–29.3 μm, breadth 16.9–23.3 μm, isthmus 6.9–11.2 μm, diameter zygospore 16.1–20.7 μm.</p><p>Type material:—   BRAZIL. Bahia: Salvador, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-38.32089&amp;materialsCitation.latitude=-12.918139" title="Search Plazi for locations around (long -38.32089/lat -12.918139)">Parque das Dunas</a>, 12°55’05.3”S, 38°19’15.2”W, 26-V-2015, G.J.P. Ramos, Maria A. Santos &amp; C.A. Ribeiro s.n. (Holotype: HUEFS220175!)  .</p><p>Habitat: — tank bromeliad ( Hohenbergia littoralis L.B.Smith); pH = 4.8, water temperature = 29.5 ºC, conductivity = 0.02 mS cm-1, total solids dissolved = 0.01 ppt, dissolved oxygen = 4.6 mg L- 1.</p><p>Etymology: — Epithet  bahianum is derived from Bahia, the geographic area (Brazilian state) where the species was collected, meaning from Bahia.</p><p>Differential diagnosis: —Regarding morphology,  Cosmarium bahianum is similar to  C. inconspicuum West &amp; G.S. West (1896: 154), however, this species is distinct from the first one by having smooth cell wall, zygospore irregularly ovoid and smaller cells dimensions (length 13,5–14,5 μm, breadth 9,5–11 μm, isthmus 4,8–5,7 μm, diameter zygospore 14,5–17 μm).</p><p>The present new species, considering the apical cell view, includes two morphotypes: one elliptical and the other one subtriangular. The subtriangular morphotype was less common and usually showed larger cell dimensions (L&gt; 25 μm, B&gt; 20 μm, I&gt; 10 μm) than the elliptical morphotype. During the observation period, it was very common to find cells dividing (Figs. 11–14), sometimes in an anomalous way (Fig. 15).</p><p>Subtriangular morphotypes are known for a few varieties of  Cosmarium such as  C. obliquum var. trigonum West (1892:149) and  C. excavatum Nordstedt var. trigonum Lagerheim (1886: 236) .</p><p>The presence of zygospore is essential for the correct identification of some  Cosmarium species, mainly the tiny ones that have very similar morphologies (Coesel &amp; Krienitz 2008). Although Croasdale &amp; Flint (1986) considered that  Cosmarium zygospores are rarely found in nature, in our samples they were very common. This may be related to the environmental adverse conditions, since during certain periods of the year, due to low rainfall regime, bromeliads tend to dry out or hold very little available water, possibly stimulating algae to  form zygospores .</p><p>Cosmarium bahianum zygospores range from globose to elliptical (the most common) (Figs. 16–22), always with a smooth cell wall. Next to conjugation between cells of similar radiation also formation of zygospores between the elliptical and the subtriangular morphotype was observed (Fig. 16).</p><p>Another interesting feature observed in both phenotypic expressions was the presence of a mucilaginous envelope surrounding the cell, often with radial striations. The function of this mucilaginous sheath in desmids is still unclear, but may be related to protection against predation, aid in capturing nutrients or enabling floating, since the density of mucilage is lesser than that of the cell, an important feature in planktonic species (Coesel 1994, Brook &amp; Johnson 2011). As for our study, we believe that extracellular mucilage will be an explanation for the adaptive success of this  Cosmarium in the bromeliad tank, minimizing the effects of desiccation of the environment.</p><p>The newly described species was extremely abundant in the  H. littoralis tank, and the only desmid recorded in the sampling unit. In the present study a population of about 200 specimens was examined.</p><p>Regarding the environment, the abiotic water conditions such as acidic pH (4.8), high temperature (29° C) and low electric conductivity (0.02 mS cm-1) are favorable for the development of desmids (Brook 1981, Coesel 1996). Other studies reported that bromeliad tanks constitute environments for the development of  Cosmarium species and other desmid taxa (Sophia 1999, Ramos et al. 2011), including species that were mentioned for the first time for Brazil such as  Euastrum crameri Raciborski (1889: 104) (Sophia et al. 2004).</p><p>The bromeliad  Hohenbergia littoralis is endemic to Brazil. Its distribution is restricted to the north coast of the Bahia state, in the “restingas” of Abaeté and Baixios, their occupation area being lesser than 500 km ². According to Forzza et al. (2013),  H. littoralis is considered an endangered species due to the eradication of the natural vegetation for the planting of  Cocos nucifera Linnaeus (1753:1188) (coconut trees) near the beach line, together with the urban expansion and development of tourism in the region. If their natural habitat is threatened,  C. bahianum will also be endangered. Therefore, preservation of  H. littoralis and other bromeliads from “Restinga” is absolutely essential as potential habitat for certain groups of algae, especially the desmids. According Šťastný &amp; Kouwets (2012), temporary ponds can house unfamiliar and/or not yet described desmid species.</p><p>Finally, we emphasize the need for more detailed studies of algae of phytotelmata environments in tropical regions, as they may reveal new species for science with particular characteristics concerning living in such water stress environments.</p></div>	https://treatment.plazi.org/id/481087A9E14AFFA5FF1BFBAFFE99FBA0	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Ramos, Geraldo José Peixoto;Bicudo, Carlos Eduardo De Mattos;Moura, Carlos Wallace Do Nascimento	Ramos, Geraldo José Peixoto, Bicudo, Carlos Eduardo De Mattos, Moura, Carlos Wallace Do Nascimento (2017): Cosmarium bahianum, sp. nov. (Desmidiaceae), a new desmid species from a phytotelm habitat in the Brazilian restinga. Phytotaxa 291 (1): 66-72, DOI: 10.11646/phytotaxa.291.1.6, URL: http://dx.doi.org/10.11646/phytotaxa.291.1.6
