Chinia gen.nov.—the second diatom genus simonsenioid raphe from mangroves in Fujian,China

A new monotypic diatom genus Chinia gen.nov.from estuarine mangrove habitats in Fujian,China is described.Light,scanning and transmission electron microscopy observations of its morphology show that this diatom differs from any established raphid diatom genus.The new genus is distinguished by a strongly undulate valve face,eccentric raphe canal,and perforated copulae.Its distinctly elevated and perforated raphe canal,classifi ed as simonsenioid type,is supported by sparse infundibulum-like portulae,and the portulae are separated by large fenestrae.The valves of Chinia also have hymenate areolar occlusions and the raphe lacks a central nodule.However,unlike most Bacillariaceae with two plastids,including Simonsenia,Chinia has a single plastid similar to those in Entomoneis and Surirella.Despite the similarities to Simonsenia,Chinia features porous raphe canal and loose striation,which is different from those of Simonsenia that has a solid raphe canal and distinct rows of areolae.These distinctive cytological and morphological characters suggest an affinity of the new genus to the Bacillariaceae.

Erratum to:Chinia gen.nov.—the second diatom genus simonsenioid raphe from mangroves in Fujian,China

Erratum to:https://doi.org/10.1007/s00343-021-1067-0 The title of this article contains a few mistakes.The correct one is given below:Chinia gen.nov.—a second diatom genus with the simonsenioid raphe type from mangroves in Fujian Province,China*The online version of the original articles can be found at:https://doi.org/10.1007/s00343-021-1067-0.

Methylmercury and sulfate-reducing bacteria in mangrove sediments from Jiulong River Estuary,China

Estuaries are important sites for mercury （Hg） methylation, with sulfate-reducing bacteria （SRB） thought to be the main Hg methylators. Distributions of total mercury （THg） and methylmercury （MeHg） in mangrove sediment and sediment core from Jiulong River Estuary Provincial Mangrove Reserve, China were determined and the possible mechanisms of Hg methylation and their controlling factors in mangrove sediments were investigated. Microbiological and geochemical parameters were also determined. Results showed that SRB constitute a small fraction of total bacteria （TB） in both surface sediments and the profile of sediments. The content of THg, MeHg, TB, and SRB were （350 ± 150） ng/g, （0.47 ± 0.11） ng/g, （1.4× 10^011 ± 4.1 × 10^9） cfu/g dry weight （dw）, and （5.0× 10^6 d： 2.7 × 10^6） cfu/g dw in surficial sediments, respectively, and （240 ± 24） ng/g, （0.30 ± 0.15） ng/g, （1.9 × 10^11 ± 4.2 × 10^9） cfu/g dw, and （1.3 × 10^6 ± 2.0 × 10^6） cfu/g dw in sediment core, respectively. Results showed that THg, MeHg, TB, MeHg/THg, salinity and total sulfur （TS） increased with depth, but total organic matter （TOM）, SRB, and pH decreased with depth. Concentrations of MeHg in sediments showed significant positive correlation with THg, salinity, TS, and MeHg/THg, and significant negative correlation with SRB, TOM, and pH. It was concluded that other microbes, rather than SRB, may also act as main Hg methylators in mangrove sediments.