Taxonomic study of Scytosiphon (Phaeophyceae) from temperate coasts of Argentina.

Scytosiphon is a common intertidal genus widely distributed on temperate coasts worldwide. Recently, eight species have been delimited with molecular tools. Although S.

Toxic effects of chlorpyrifos, cypermethrin and glyphosate on the non-target organism Selenastrum capricornutum (Chlorophyta).

The toxic effects of the insecticides chlorpyrifos and cypermethrin, and the herbicide glyphosate on the growth, biovolume and ultrastructure of the green microalgae Selenastrum capricornutum were evaluated. Concentrations between 9.37-150 mg L-1 of chlorpyrifos, 3.

Short-term temporal dynamics of morphological and feeder functional groups and species richness in relation to seasonal changes.

This study examines the distribution of primary and secondary space holders integrated in morphological and feeder functional groups as well as the species richness over the seasons on northern Patagonian rocky shores. We also evaluated whether the temporal changes in species richness, assemblage structure and species turnover were related to seasonal changes. These patterns were studied by non-destructive samplings between December 2013 and March 2015.

Influence of microphytobenthos on the sedimentary organic matter composition in two contrasting estuarine microhabitats.

The influence of microphytobenthic community on the composition of sedimentary organic matter was evaluated in two Bahía Blanca estuary microhabitats contrasting in vegetation and hydrodynamic conditions; namely, S1 located in a Sarcocornia perennis saltmarsh with macroscopic microbial mats and S2 in a mudflat without macroscopic microbial mats or vegetation. Moisture, organic matter, chlorophyll a, phaeopigments, carbohydrates (CH), proteins (PRT), and abundance and structure of microphytobenthic community were evaluated in surface sediments. Higher moisture was observed at S2 and was related to the proximity of this site to the subtidal zone and the effect of the environmental variables temperature and rain.

Meridionella gen. nov., a New Genus of Cystocloniaceae (Gigartinales, Rhodophyta) from the Southern Hemisphere, Including M. obtusangula comb. nov. and M. antarctica sp. nov.

The classification of Cystoclonium obtusangulum has been questioned since the species was first described by Hooker and Harvey as Gracilaria? obtusangula. The objective of this study was to provide the first comprehensive taxonomic analysis of Cystoclonium obtusangulum, based on DNA sequences coupled with morphological observations made on syntype specimens and new collections. Sequence divergences of rbcL, UPA, and COI-5P, and maximum-likelihood phylogenies for rbcL and 18S demonstrated that specimens identified as Cystoclonium obtusangulum represent a clade of two distinct species that are distantly related to the generitype Cystoclonium purpureum.

Cryptic Haploid Stages in the Life Cycle of Leathesia marina (Chordariaceae, Phaeophyceae) Under In Vitro Culture.

We evaluated the life cycle of Leathesia marina through molecular analyses, culture studies, morphological observations, and ploidy measurements. Macroscopic sporophytes were collected from two localities in Atlantic Patagonia and were cultured under long-day (LD) and short-day (SD) conditions. Molecular identification of the microscopic and macroscopic phases was performed through the cox3 and rbcL genes and the phylogeny was assessed on the basis of single gene and concatenated datasets.

Modeling phytoplankton community in reservoirs. A comparison between taxonomic and functional groups-based models.

In this paper we address the formulation of two mechanistic water quality models that differ in the way the phytoplankton community is described. We carry out parameter estimation subject to differential-algebraic constraints and validation for each model and comparison between models performance. The first approach aggregates phytoplankton species based on their phylogenetic characteristics (Taxonomic group model) and the second one, on their morpho-functional properties following Reynolds' classification (Functional group model).

Effects of chlorpyrifos on the growth and ultrastructure of green algae, Ankistrodesmus gracilis.

The effect of the organophosphorus insecticide chlorpyrifos on the growth, biovolume, and ultrastructure of the green microalga Ankistrodesmus gracilis was evaluated. Concentrations of 9.37, 18.

Secondary zoospores in the algal endoparasite Maullinia ectocarpii (Plasmodiophoromycota).

The present paper deals with the ultrastructure of zoospores produced by the plasmodiophorid Maullinia ectocarpii, living in the marine algal host Ectocarpus siliculosus. The zoospores described here are very similar to secondary zoospores of Polymyxa graminis and Phagomyxa sp. (the latter an algal endoparasite, also).