Pseudostaurosira crateri sp. nov. (Fragilariaceae, Bacillariophyta), a new small araphid, fossil diatom species from the Pleistocene (Atlantic Forest, Brazil)

Phytotaxa ◽  
2021 ◽  
Vol 496 (2) ◽  
pp. 105-120
Author(s):  
GISELE C. MARQUARDT ◽  
DENISE C. BICUDO ◽  
CARLOS E. DE M. BICUDO ◽  
MARIE-PIERRE LEDRU ◽  
LUC ECTOR ◽  
...  

Pseudostaurosira crateri sp. nov. is described from fossil material analyzed from a Quaternary sediment core retrieved from the Colônia basin (located in the Brazilian Coastal Plain, Atlantic Forest, São Paulo Metropolitan Region). Light and scanning electron microscopy revealed its morphology and enabled its comparison with morphologically similar species from European and African rivers and lakes. The new species features wide and short vimines, a particular characteristic of the genus Pseudostaurosira, in addition to many other exclusive features that distinguish it from any other species in the genus reported to date. Some of these characteristics are: (i) apical pore fields composed of small poroids placed within cavernous troughs carved deep into the valve, (ii) absence of blisters or depositions along the valve mantle edge, (iii) small-sized valve, (iv) presence of incipient or rudimentary spines located on raised virgae at the valve face/mantle junction, and (v) internal accumulations of siliceous material on the volae appearing as concentric discs partially occluding the depression into which the areolae open internally. We further discuss the morphological features of similar species ascribed to the genera Pseudostaurosira, Pseudostaurosiropsis, Staurosirella, Frankophila, and Popovskayella based on literature information. Finally, this study contributes to the knowledge on diatom diversity and its biogeography, especially those from tropical regions, in addition to providing a taxonomical basis for its use as biological markers for paleoenvironmental reconstruction.

2019 ◽  
Vol 152 (1) ◽  
pp. 84-92
Author(s):  
Piero G. Delprete ◽  
Jomar G. Jardim

Background – Ongoing studies of Brazilian Rubiaceae revealed an undescribed species of Amaioua endemic to Atlantic Forest (Restinga and Semideciduous forest) of the state of Bahia, which is here described and illustrated, and its morphological characters are discussed and compared with those of similar species. Methods – This study is based on examinations of herbarium specimens, samples preserved in 60% ethanol, field observations, and digital images. Herbarium specimens of the CAY, CEPEC, HBR, IBGE, K, MBM, NY, RB, U, UB, UFG, and US herbaria were directly studied. Additional images of herbarium specimens were studied online. Results – Amaioua longipedicellata Delprete & J.G.Jardim is here described, illustrated and compared with the two most similar species, i.e., A. glomerulata (Lam. ex Poir.) Delprete & C.H.Perss. and A. intermedia Mart. A table comparing the morphological characters of these three species, and an appendix with selected specimens studied of A. glomerulata and A. intermedia are included.


Phytotaxa ◽  
2016 ◽  
Vol 273 (2) ◽  
pp. 115 ◽  
Author(s):  
KELLY CRISTINA DA SILVA-GONÇALVES ◽  
JOSÉ FERNANDO A. BAUMGRATZ ◽  
ANDRÉ FELIPPE NUNES-FREITAS

A new species of Bertolonia (Melastomataceae; Bertolonieae) endemic to the Brazilian Atlantic Forest is described and illustrated. Bertolonia organensis is known from only one locality in the Serra dos Órgãos National Park, state of Rio de Janeiro. The main diagnostic characteristics that distinguish B. organensis are the leaves with bullate adaxial surface and foveolate abaxial surface, cordate base and seven acrodromous veins, petiole and hypanthium glandulose-punctate, setulose and setulose-glandulose, the external calyx lobes erect, thick, narrow-triangular, apex acuminate-glandulose, margin entire, not ciliate, and the anthers connective dorsally appendaged, trilobed or with an acute calcar. Comparisons with similar species, geographic distribution and habitat are presented for the new species, as well as a key to identify all Bertolonia taxa known from the state of Rio de Janeiro. Bertolonia organensis is classified as Critically Endangered (CR).


The Holocene ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 108-120
Author(s):  
Angelica Ballesteros-Prada ◽  
Mariel Luengo ◽  
Isabel Vilanova ◽  
Enrique Fucks ◽  
Emiliana Bernasconi

In this investigation, we carried out a Mid-Holocene paleoenvironmental reconstruction based on fossilized benthic foraminifera, retrieved from sedimentary deposits located in Bahía Samborombón coastal plain. A total of 38 species, grouped into 19 genera, were identified. The assemblage, constituted mainly by Buccella peruviana (d’Orbigny), Cribroelphidium poeyanum (d’Orbigny), Ammonia parkinsoniana (d’Orbigny) and Ammonia tepida (Cushman), indicate predominantly abnormal marine conditions, characterized by low oxygen levels between ca. 6880–6640 and 5600–5430 yrs cal. BP. During this interval, a quantitative analysis carried out on the assemblages as well as indexes suggest found three different paleoenvironments. The first one, occurring ca. 6880–6640 yrs cal. BP, was a brackish environment with low oxygenation levels and low bottom energy. Then, ca. 6500–6250 yrs cal. BP, an environment with more marine influence, increased oxygen levels and higher energy prevailed. This higher oxygenation could be related to the flow of seawater into the area during the Mid-Holocene sea-level highstand. The third paleoenvironment developed ca. 5590–5430 yrs cal. BP, was under a gradual transition back to a brackish environment with low oxygen levels as well as low energy.


Author(s):  
Camila Rodrigues Cabral ◽  
Leidiane Pereira Diniz ◽  
Alef Jonathan da Silva ◽  
Gustavo Fonseca ◽  
Luciana Silva Carneiro ◽  
...  

Assessing zooplankton biodiversity is essential to support freshwater management/conservation programs. Here, we investigated the zooplankton community structure from 180 shallow lakes in northeastern Brazil and analyzed them according to biome (Atlantic Forest or Caatinga), the origin of ecosystems (natural or man-made lakes), and habitat type (pelagic or littoral). Additionally, we provided an updated list of zooplankton species. We registered 227 species (137 Rotifera, 65 Cladocera, 25 Copepoda). The most common species of each major group among all lakes were the cladoceran Ceriodaphina cornuta, the rotifers Brachionus havanaensis and Lecane bulla, and the copepod Termocyclops decipiens. Species related to aquatic vegetation, as the Lecanidae rotifers and phytophilous cladocerans, were more frequent along Atlantic Forest biome and natural lakes. On the other hand, species that are bioindicators of eutrophic waters were more common at the Caatinga biome and man-made lakes. Atlantic Forest and Caatinga biomes had similar species richness, but different community compositions for all zooplankton groups, reinforcing the Caatinga significance for the Brazilian aquatic biodiversity. The type of habitat was the most important factor structuring species richness, with higher richness in the littoral region when compared to the pelagic. A result of many unique species of Cladocera and Rotifera associated with the aquatic vegetation were observed. The findings demonstrated that conservation/management plans cannot generalize zooplankton species distribution across different biomes, origins and even within a single lake, between the pelagic and littoral zones.


2017 ◽  
Vol 107 (5) ◽  
pp. 634-644 ◽  
Author(s):  
R.D. Coutinho-Silva ◽  
M.A. Montes ◽  
G.F. Oliveira ◽  
F.G. de Carvalho-Neto ◽  
C. Rohde ◽  
...  

AbstractSeasonality is an important aspect associated with population dynamic and structure of tropical insect assemblages. This study evaluated the effects of seasonality on abundance, richness, diversity and composition of an insect group, drosophilids, including species native to the Neotropical region and exotic ones. Three preserved fragments of the northern Atlantic Forest were surveyed, where temperatures are above 20 °C throughout the year and rainfall regimes define two seasons (dry and rainy). As opposed to other studies about arthropods in tropical regions, we observed that abundance of drosophilids was significantly higher in the dry season, possibly due to biological aspects and the colonization strategy adopted by the exotic species in these environments. Contrarily to abundance, we did not observe a seasonal pattern for richness. As for other parts of the Atlantic Forest, the most representative Neotropical species (Drosophila willistoni, D. sturtevanti, D. paulistorum and D. prosaltans) were significantly more abundant in the rainy season. Among the most abundant exotic species, D. malerkotliana, Zaprionus indianus and Scaptodrosophila latifasciaeformis were more importantly represented the dry season, while D. simulans was more abundant in the rainy period. The seasonality patterns exhibited by the most abundant species were compared to findings published in other studies. Our results indicate that exotic species were significantly more abundant in the dry season, while native ones exhibited an opposite pattern.


2014 ◽  
Vol 14 (4) ◽  
Author(s):  
Renan Maestri ◽  
Daniel Galiano ◽  
Bruno Busnello Kubiak ◽  
Jorge Reppold Marinho

Small land mammals possess features that significantly influence the dynamics of ecosystems and participate in various levels of the food web. In the Brazilian Atlantic Forest the richness of these animals is high, which makes them even more ecologically and numerically relevant in this environment. In this context, we investigated the species composition of small mammals in an unexplored area of southern Brazil, and compared the species composition of this area with other Atlantic Forest regions in order to understand how this community is related to others. The study area was located in an interior Atlantic forest formation, at a transition region between deciduous and Araucaria forests. Small mammals were captured at five collection points using pitfall traps. We compared the species composition found in our studied area with the composition of other 11 studies in different regions by a cluster analysis, and we investigated the presence of spatial autocorrelation between communities with a Mantel test. We recorded 779 individuals from 21 species of small rodents (15 species) and marsupials (six species) during the 13 months of the collection period. This richness was high compared to other studies conducted in the Atlantic Forest formations near to coastline and in interior forest formations. This may be a result of the conditions provided by this transition area (deciduous and Araucaria forests), where could be found elements of the both forests formations, which probably allows the establishment of small mammal species from both forest types. Despite differences in sampling effort of the studies, our results suggest that the interior forest formations may harbor a number of species comparable to the formations near the coast. The species composition of this area was similar to those found in other interior forest formations with the same phytophysiognomy characteristics and at nearby regions, and it was less similar to the distant formations located in southeastern and northeastern Brazil and nearby to the coastline. This can be a result of both the spatial autocorrelation (i.e. more nearby communities tend to have more similar species composition) and the differences of forest characteristics among regions.


Botany ◽  
2009 ◽  
Vol 87 (4) ◽  
pp. 409-427 ◽  
Author(s):  
Peter A. Siver ◽  
Paul B. Hamilton ◽  
Jeffery Pelczar

During our investigations of freshwater sites along the Atlantic Coastal Plain of North America we had the opportunity to critically study five interesting diatoms with light (LM) and scanning electron microscopy (SEM), each of which is described here as a new species. Two of the organisms are in the genus Eunotia , Eunotia lewisii Siver & Hamilton sp. nov. and Eunotia quadra Siver & Hamilton sp. nov.; two in Frustulia , Frustulia crispula Siver, Pelczar, & Hamilton sp. nov. and Frustulia inculta Siver, Pelczar, & Hamilton sp. nov.; and the last is Neidium trainori Siver & Hamilton sp. nov. All five species are reported from acidic, poorly buffered, dilute waterbodies high in dissolved humic substances. Two of the taxa are found in suites of waterbodies in close geographic proximity, two in somewhat disjunct regions, and the fifth is only known from the type locality. The relationships of each taxon to similar species are discussed.


2018 ◽  
Vol 151 (2) ◽  
pp. 262-270
Author(s):  
Cristiano C. Nascimento ◽  
Mariana C.A. Sá ◽  
José Luiz Bezerra ◽  
Felipe Wartchow

Background – Amanita Pers. has a worldwide distribution and is one of the most well-known fungal genera in terms of both morphotaxonomy and molecular phylogenetics, consisting of many edible, as well as poisonous, even lethal, mushrooms. The genus is also known to form ectomycorrhizal associations with angiosperms and gymnosperms and play an important role in ecosystems. Although previous studies have already pointed out the high diversity of the genus Amanita in tropical areas, only a few recent studies continue to record and/or describe new species of Amanita from Brazilian territory. Herein, an additional, morphologically striking new species of Amanita sect. Lepidella is described from Northeast Brazil.Methods – The new species was collected at ‘Parque Estadual Serra do Conduru’ (PESC), located in the municipalities of Uruçuca, Itacaré e Ilhéus, Bahia state. The park is an Atlantic Forest protected area with about 7000 ha in a region with a high degree of endemism. For morphological analysis, standard methods for Amanita were followed.Key results – Amanita dulciodora is described as new species from Atlantic Forest remnants in southeast Bahia. It is assignable to Amanita stirps Crassiconus within Amanita subsect. Solitariae and is mainly characterized by its (1) medium-size basidiomata with cap colour and appearance dominated by universal veil at first; (2) distinctly coloured acute-pyramidal, truncate-pyramydal to verrucose warts which are mainly composed of irregularly disposed, ovoid to subglobose to clavate cells intermixed with very abundant filamentous hyphae; (3) mostly ellipsoid to elongate amyloid basidiospores and (4) the common presence of clamps at the basal septa of basidia. It was compared with its similar species, A. crassiconus and illustrated with line drawings and photographs.


Phytotaxa ◽  
2021 ◽  
Vol 479 (1) ◽  
pp. 1-22
Author(s):  
KIM J. KRAHN ◽  
ANJA SCHWARZ ◽  
CARLOS E. WETZEL ◽  
SERGIO COHUO-DURÁN ◽  
GERHARD DAUT ◽  
...  

Three new needle-shaped Fragilaria species from freshwater lake Apastepeque in El Salvador (Fragilaria salvadoriana sp. nov., F. maarensis sp. nov.) and subsaline lake Nam Co on the Tibetan Plateau (F. huebeneri sp. nov.) are described and compared based on light and scanning electron microscopy observations and morphometric analyses. Fragilaria salvadoriana sp. nov. is characterized by narrowly linear-lanceolate, sometimes centrally constricted valves, subcapitate to rarely capitate apices, and a distinct, dented appearing central area. Striae are composed of 2−5 occluded areolae. It can be differentiated from similar needle-shaped species by the valve outline, relatively low striae density, and shark fin-shaped spines. Characteristic of F. maarensis sp. nov. are a very narrowly lanceolate valve outline and subcapitate apices. The apical pore field is composed of 2–3 rows of poroids and acute, irregularly oriented spines are present at the junction between valve face and mantle. This taxon is clearly different from other Fragilaria species, displaying a high length-to-width ratio and a low number of areolae per stria. The Tibetan species, F. huebeneri sp. nov., forms long ribbon-like colonies linked together by spatula-shaped spines. Valves have subcapitate apices, a spindle- to needle-shaped outline and an indistinct central area. Striae are alternate and composed of 3–5 areolae per stria. Teratological forms of F. huebeneri sp. nov. were commonly observed in the sediment trap samples. Fragilaria salvadoriana sp. nov. and F. maarensis sp. nov. were found in a warm, tropical crater lake characterized by low conductivity and dissolved oxygen content, medium alkaline pH, and magnesium-calcium-bicarbonate-rich waters. Fragilaria huebeneri sp. nov. was frequent in a large, high elevation lake with increased specific conductivity, alkaline pH and sodium-bicarbonate-rich waters. The new species are compared to morphologically similar species from the genus Fragilaria Lyngbye and ecological preferences are discussed.


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