Lithotrichon pulchrum Darienko and Pröschold, 2017

Kwon, Dae Ryul, Nam, Hyun Ju & Nam, Bok Yeon Jo and Seung Won, 2022, New records of two ulvophycean freshwater species, Lithotrichon pulchrum (Ulvales, Ulvophyceae) and Tupiella speciosa (Ulotrichales, Ulvophyceae), Journal of Species Research 11 (2), pp. 79-88 : 82-84

1) Lithotrichon pulchrum Darienko and Pröschold, 2017

Material examined. Sample was collected from the Samcheok Harbor , Jeongha-dong , Samcheok-si, Gangwon-do, Republic of Korea (37°26′14.2″N, 129°11′34.0″E) on 09 April 2019 .

Description. Lithotrichon pulchrum is a microscopic and filamentous alga. Vegetative cells were round to laterally compressed oval-shaped and measured 5.9-8.8 μm in diameter with a thick cell wall ( Figs. 1A , 2A ). Cells possess a nucleus, Golgi body, mitochondria with plate-like cristae, and a single parietal chloroplast with a pyrenoid encased by starches ( Figs. 1A, B , 2A- D ). The pyrenoid matrix was penetrated by the thylakoid membrane(s) ( Fig. 2B ). The erect system is formed by short filaments, 12.0-23.5 μm long and 3.5-5.5 μm wide, generally 2-4 times longer than broad ( Fig. 1B, C ). Branching is mostly bilateral, and younger cells are L-shaped bent to the side ( Fig. 1D ). In filament form, the cell had one or two pyrenoids and two types of cell walls ( Fig. 2E, F ).

Distribution. Germany ( Darienko and Pröschold, 2017) and Republic of Korea.

Voucher slides. Two slides of gelatin-embedded specimens (NNIBRCL16651 and NNIBRCL16654) were deposited at Nakdonggang National Institute of Biological Resources, Korea.

Remarks. Lithotrichon pulchrum was known as photobiont of lichen Hydropunctaria rheitrophila ( Darienko and Pröschold, 2017; Sanders and Masumoto, 2021), however, Korean strain was isolated in planktonic seawater samples and cultured BG 11 freshwater medium. This means L. pulchrum might have diverse habitats and salinity tolerance. Zoospores of German strain were contained in oval-shaped zoosporangia, but any zoospores with anterior stigma for asexual reproduction were not observed in the Korean strain ( Darienko and Pröschold, 2017).

Figures

Fig. 1. Morphology of Lithotrichon pulchrum Samcheokhang190409G.A. Vegetative cells; B. The erect system formed by a short filament cell(arrow); C. Filament cells; D. Bilaterally branched from. Py, pyrenoid. Scale bars: 10μm.

Fig. 2. Ultrastructure of Lithotrichon pulchrum. A. Vegetative cell; B. Pyrenoid penetrated by thylakoid membrane (arrow); C. Mitochondrion; D. Golgi body; E. Flament cell with one pyrenoid; F. Flament cell with two pyrenoids. Cp, chloroplast; PCW, primary cell wall; G, Golgi body; Mt, mitochondrion; N, nucleus; Py, pyrenoid; S, starch; SCW, secondary cell wall. Scale bars:A=1 μm, B-D=0.5 μm, E, F=2 μm.