This study aims to understand the viability of diatoms exhibiting teratological frustules and their reproduction capacities within a Cd-impacted population to predict their return learn more to normal diatom forms. We worked on a frequently encountered species in French hydrosystems: Planothidium frequentissimum (Lange-Bertalot) Round & L. Bukhtiyarova. First, a 21-d contamination phase highlighted increasing inductionof different teratological

types in response to two levels of Cd contamination: 20 and 100 μg · L−1. The deformity counting indicated that Cd firstly generated striae and mixed teratologies, then affected the central area and the valves. Second, a 28-d decontamination selleck compound phase demonstrated the Cd depuration capacity of Planothidium frequentissimum. Cd half-lives appeared relatively low, ~6 d for the 100 μg · L−1 condition. Moreover, the decontamination phase showed a decrease in teratology abundances, but

a still incomplete recovery after 28 d. Deformations of the striae appeared to be the most sustainable phenotype since they were still significantly higher than in reference cultures at the end of the decontamination phase for both Cd cultures. “
“Benthic diatoms form a particularly important community in oligotrophic lakes, but factors influencing their distribution are not well known. This study reports the depth distribution of living motile and total diatoms (living plus dead diatoms) on both natural (from sand to fine organic mud) and artificial substrates in an oligotrophic

lake. On artificial substrates, motile diatom densities peaked in abundance (24–30 cells · mm−2) between 0.6 and 1.9 m depth; on natural sediment surfaces, motile diatoms were generally more numerous and peaked in abundance (925 cells · mm−2) at 1.3 m depth. Total diatom densities on artificial substrates were highest (1260 valves · mm−2) at 0.6 m depth, with very low values below 3 m depth; on natural sediment surfaces, total diatom abundances were generally much higher (21600 valves · mm−2) at 3 m depth and declined gradually with depth. Significant relationships were found between light and diatom densities on the artificial substrate. Ordination 上海皓元医药股份有限公司 analysis indicated that substrate type significantly correlated with the variation of diatom composition on artificial and natural substrates. Our results suggest that in oligotrophic lakes, light influences benthic diatom abundance, whereas substrate type has more influence on benthic diatom composition. “
“Few members of the well-studied marine phytoplankton taxa have such a complex and polymorphic life cycle as the genus Phaeocystis. However, despite the ecological and biogeochemical importance of Phaeocystis blooms, the life cycle of the major bloom-forming species of this genus remains illusive and poorly resolved.