Ultrastructure of three Species of Entomoneis (Bacillariophyta) from Lake Qinghai of China, with reference to the external areola occlusions

Abstract

Three sympatric Entomoneis species, found at the same specific locality in Lake Qinghai, China, are studied by using light and scanning electron microscope. Two species are proposed as new to science and named as E. sinensis sp. nov. and E. qinghainensis sp. nov. The third species is identified as E. paludosa (W. Smith) Reimer. Entomoneis sinensis has a linear-lanceolate valve outline and Ƨ-shaped keel, bears two distinct 8-shaped loops formed by the valvocopula pars media in each cell and each of its stria is composed of either a long hymen strip or a long hymen strip plus one separated areola close to the raphe. Its hymen strip belongs to Type Two, which is a siliceous membrane strip perforated by two rows of linear pores next to transapical costae and two rows of rounded pores between these two rows of linear pores. Entomoneis qinghainensis has large cells, very high keel and evident hymen strip regions like a U-shaped neck pillow at the middle of valve face. Its hymen strip belongs to Type One, which is a siliceous membrane strip perforated by irregularly distributed round pores. Entomoneis paludosa also has the hymen strip regions that are worm-like and close to the raphe canal. Its hymen strip is same as that of E. qinghainensis. The two kinds of the outside areola occlusions in Entomoneis are compared, summarised and discussed.

Diatoma sinensis: a new diatom species (Bacillariophyta) found in the brackish Lake Qinghai, China

“… Diatoma sinensis was found on submerged stones with yellow-brown surfaces, occurring with Berkeleya fennica Juhlin-Dannfelt (1882) , Pinnularia qinghainensis Bing Liu & S. Blanco ( Deng et al 2021 ), Entomoneis sinensis Bing Liu & D.M. Williams ( Long et al 2022 ), E. qinghainensis Bing Liu and D.M. Williams ( Long et al 2022 ), E. paludosa (W. Smith) Reimer ( Long et al 2022 ), Ctenophora sinensis Bing Liu & D.M.…”

“…Williams ( Long et al 2022 ), E. qinghainensis Bing Liu and D.M. Williams ( Long et al 2022 ), E. paludosa (W. Smith) Reimer ( Long et al 2022 ), Ctenophora sinensis Bing Liu & D.M. Williams ( Liu et al 2020 ), and some species of Navicula Bory ( Bory de Saint-Vincent 1822 ), Gyrosigma Hassall (1845) , Nitzschia Hassall (1845) , and Surirella Turpin (1828) .…”

“…Recently, more new species from Lake Qinghai belonging to the genera Ctenophora (Grunow) Williams and Round, Pinnularia Ehrenberg and Entomoneis (Ehren.) Ehrenberg have been published ( Liu et al 2020 ; Deng et al 2021 ; Long et al 2022 ). Thus, there may be numerous endemics yet to be discovered and described from material collected in this ancient lake.…”