Euastrum and Micrasterias (family Desmidiaceae) in lentic tropical ecosystem, Brazil

Abstract

This study aimed to perform the taxonomic survey of Euastrum and Micrasterias in a lentic tropical environment, seeking to contribute to the knowledge on biodiversity and geographical distribution of the Zygnemaphyceae. Conducted at the Samambaia Reservoir, ten samples were collected in the dry season (24/09/10 and 04/11/10) and ten in the rainy season (06/01/11 and 02/03/11). Periphyton was sampled from stems of aquatic plants (Cyperaceae), which were in the marginal area of the reservoir. With the floristic survey, 22 taxa were identified representing the genus Euastrum (9) and Micrasterias (13), of these 16 are new records for the State of Goiá s. In relation the frequency of occurrence and the seasonal period, 19 taxa were classified in the rare category and three in common, nine species were recorded during the dry season, while four only in the rainy season. Keywords: desmids, periphyton, sazonal, taxonomy, Zygnemaphyceae.

Taxonomic notes on the species of the genus Micrasterias (Desmidiaceae, Conjugatophyceae) from the Metropolitan Region of Salvador, Bahia, Brazil

“…Among the MRS samples the polar lobe was either rectilinear or slightly convex, with 2-denticulate or only 1-denticulate extremities. The taxon generally occurs in oligotrophic to mesotrophic, slightly acidic (pH < 7.4) environments, where they make up the metaphyton or periphyton (Felisberto and Rodrigues 2005, Sophia et al 2005, Silva and Felisberto 2015. Despite being recorded in more than half of the municipalities studied, we consider it rare in the MRS, occurring in only 17 of the 275 samples analyzed (Table 2).…”

“…Micrasterias laticeps var. acuminata has a wide geographic distribution, occurring in all regions of Brazil, both in plankton and periphyton from oligotrophic to acidic (pH < 5.9) mesotrophic environments (Camargo et al 2009, Aquino et al 2014, Araújo et al 2015, Silva and Felisberto 2015). Although we recorded this variety in most of the municipalities of the MRS, it occurred in only 12% of our samples, and thus, we considered it to be occasional (Table 2).…”

“…Notes. This species can exhibit variation in the projection of the lateral and basal lobes, concavity of the polar lobe, and the presence or absence of supraisthmal facial decoration (Růžička 1981, Ribeiro et al 2015, Silva and Felisberto 2015). In the samples from the MRS, the most varied character in the study specimens was the projection of the lateral and basal lobes, which were mostly projected horizontally rather than diagonally.…”

“…pussila complex originating in Australia. In Brazil, the variety is referred to phytoplankton and the periphyton of oligotrophic and mesotrophic environments (Felisberto and Rodrigues 2005, Aquino et al 2014, Silva and Felisberto 2015). Although we found M. truncata var.…”

New records of desmids from Ropar wetland (a Ramsar Site) of Punjab, India

“…The diversity of desmids from different regions of the world has been explored by many workers (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). In India, many studies have been reported from different parts, like from Dehradun (28), Ladakh (29,30), Uttar Pradesh (31), Karnataka (32,33), Maharashtra (12,14,(34)(35)(36)(37)(38)(39), Western Himalayas (40), Himachal Pradesh (41), Eastern Himalaya (42), West Bengal (43) etc.…”