Eunotia odebrechtiana Metzeltin & Lange-Bertalot, 1998: 71

Luo, Fen, You, Qingmin, Yu, Pan, Pang, Wanting & Wang, Quanxi, 2019, Eunotia (Bacillariophyta) biodiversity from high altitude, freshwater habitats in the Mugecuo Scenic Area, Sichuan Province, China, Phytotaxa 394 (2), pp. 133-147 : 137-143

Eunotia odebrechtiana Metzeltin & Lange-Bertalot, 1998: 71 , figs 56: 1–6, 13, 14 ( Figs 28–38 )

Valve arched, dorsal margin convex, ventral margin moderately concave to almost straight in the middle, ends broadly rounded, length 35–44 μm, and breadth 6–8 μm. In SEM striae are uniseriate, 5–7/10 μm at mid-valve and up to 11– 14/10 μm near the apices ( Figs 36–37 ). Dorsal mantle with 1–4 short striae between two long striae ( Fig. 38 ). Areolae round, ca. 45/10 μm. Terminal raphe fissure oblique to the valve ( Fig. 37 ).

Remarks: Compared to the type material, our specimen had an obviously more narrow valve. Description of the type species: length 30–85 μm, breadth 8–13 μm, striae 4–7.5/10 μm. All other features were the same, especially the dispersed striae in the valve and short striae on the dorsal mantle. These features are unique to E. odebrechtiana in comparison to other species of the genus.

Habitats: Epilithic in streams and Mugecuo Lake and epiphytic (i.e., as filamentous algae) in Qisehai Lake. Sample numbers: SC201508032, SC201508034, SC201508042, and SC201508075.

Distribution: South America ( Metzeltin & Lange-Bertalot 1998); China (This paper).

Eunotia pomeranica Lange-Bertalot & Witkowski in Lange-Bertalot et al., 2011: 198, figs 224: 1–13; 225: 1–15; 226: 1–5 ( Figs 39–46 )

Valve arched, dorsal margin convex, ventral margin moderately concave to almost straight and parallel dorsal margin proximally, ends broadly rounded, length of 28–35 μm, and breadth of 5–6 μm. In SEM: striae uniseriate and in parallel at middle valve, becoming radial at apices ( Fig. 44 ), with 13–16/10 μm, and up to 18–20/10 μm near apices. Areolae round, ca. 40/10 μm. Terminal raphe ends oblique to the polar end ( Figs 45–46 ).

Remarks: The type material comprises two different forms, a larger and a smaller form. The species in our samples is more similar to the smaller taxa of the type material, with a description that includes a length of 24–75 μm, breadth of 6–9 μm, and striae of 11–15/10 μm ( Lange-Bertalot et al., 2011). In Poland, the species was found in Piaski

Lake, which consists of a sandy underground that contains CaCO 3 ( Lange-Bertalot et al., 2011), The habitat of Qisehai Lake is similar to Piaski Lake ( Chen et al., 2013).

Habitats: Epiphytic on filamentous algae and floating viscous or flocculent substance in Qisehai Lake. Sample numbers: SC201508075, SC201508079, and SC201508081.

Distribution: Poland ( Lange-Bertalot et al., 2011), China (This paper)

Eunotia michaelis Metzeltin, Witkowski & Lange-Bertalot in Metzeltin & Lange-Bertalot, 1996: 14, figs 34: 2–8; figs 70: 18, 19; figs 90: 5–6.

Valve arched, strong convex dorsal margin, ventral margin moderately concave to almost straight proximally, apices slightly or barely protracted and broadly rounded, length of 14–22 μm, and breadth of 4–5.5 μm. SEM striae are uniseriate 13–16/10 μm and near the ends up to 17–18/10 μm. Areolae appear round, 40–45/10 μm. Terminal raphe fissure oblique to the poles, ca. 1 μm visible on valve face ( Figs 52–54 ).

Remarks: Compared to the type material, the valves in our samples are slightly longer and narrower, and striae are denser. The description of E. michaelis is as follows: length of 16–20 μm, breadth of 4.5–6 μm, and striae 12–16/10 μm. Previously, this species has been found in Sphagnum peat bogs in sub-Artic Beer Island and European Russia. Populations were abundant at both locations ( Metzeltin & Lange-Bertalot, 1996), which varies from the habitats studied herein.

Habitats: Epiphytic on filamentous algae or floating viscous in Qisehai Lake. Sample numbers: SC201508075, SC201508079, and SC201508081.

Distribution: Germany ( Metzeltin & Lange-Bertalot, 1996), Russia ( Lange-Bertalot et al., 2011), China (This paper).

Eunotia pseudogroenlandica Lange-Bertalot & Tagliaventi in Lange-Bertalot et al., 2011: 202, figs 132: 1–67; figs 133: 1–11. ( Figs 61–71, 77 –81)

Valves are small and arched, dorsal margin clearly convex, ventral margin slightly concave or straight, apices reflected and bluntly rounded, length of 13–19 μm, breadth of 2.5–3.5 μm. SEM striae are uniseriate, 17–20/10 μm. Areolae appear round, ca. 45/10 μm ( Figs 63–64 ). Terminal raphe fissures bend toward the dorsal margin ( Fig. 64 ). The internal valve view shows one helictoglossa near the polar end ( Figs 65–67 ).

Remarks: The valve is similar to the type species ( Lange-Bertalot et al., 2011), whereas the striae are more dense in our samples. The protologue of E. pseudogroenlandica is as follows: length of 12–36 μm, breadth of 2.7–3.6 μm, striae of 15–18/10 μm.

Habitats: Epilithic in Mugecuo Lake or epiphytic on filamentous algae or floating viscous in Qisehai Lake. Sample numbers: SC201508040, SC201508079, and SC201508081.

Distribution: Siberia, Norway, Finland, France, Italy ( Lange-Bertalot et al., 2011), Macedonia ( Pavlov & Levkov, 2013), Germany ( Cantonati et al., 2010), Netherlands ( Veen et al., 2015), China (This paper).

Eunotia superpaludosa Lange-Bertalot in Lange-Bertalot et al., 2011: 231, figs 147: 48–58; figs 148: 1–23; figs 149: 1–7 ( Figs 68–79 ),

Valve curved or arched, convex dorsal margin, concave ventral margin, two sides of the valve almost parallel, apices capitated and reflected, length of 33–54 μm, and breadth of 4–5 μm. SEM observations indicate striae are uniseriate, 14–18/10 μm ( Fig. 75 ). Areolae appear round and with hollow disc velum, ca. 40/10 μm. Terminal raphe fissure bend toward the dorsal margin up to ends ( Figs 76–78 ). The striae are more dense on valve mantle ( Fig. 78 ).

Remarks: Compared to the type material ( Lange-Bertalot et al., 2011), these have similar characters in outline and size, and their terminal raphe fissure bend toward the dorsal margin up to ends. The description of E. superpaludosa is as follows: size is length 20–75 μm, breadth 2.4–4 μm. Description of breadth data may not be accurate, as the breadth of this species is approximately 4–5 μm (see pl. 148: Figs 3–5 , Fig. 7 from Lange-Bertalot et al., 2011). Species in these collected samples have more dense striae on the mantle compared to the type species. Due to the differences in density of the striae on the mantle, these cannot be classified as two species.

Habitats: Epilithic to stones in the stream, epiphytic on filamentous algae or floating viscous in Qisehai Lake. Sample numbers: SC201508034, SC201508079, and SC201508081.

Distribution: North America, Russia ( Lange-Bertalot et al., 2011), China (This paper)

FIGURES 80–81, 105. E. glacialispinosa ; 82–84: E. soleirolii ; 85, 104: E. parallel a; 86–89: E. minor ; 90: E. scandiorussica ; 91: E. palatina ; 92: E. circumborealis ; 93–95: E. nymanniana ; 96–97: E. bilunaris ; 98–99: E. monnieri ; 100–101: E. nägelii ; 102, 106: E. pseudopapilio ; 103: E. bigibboidea . LM scale bars, 10 μm.

Figures

FIGURES 28–38. E. odebrechtiana. 28–35. LM images; 36–38. SEM images; 36. Half external valve view; 37. Terminal ends of external valve; 38. Arrow show short striae of mantle in the middle. LM scale bars, 10 μm.

FIGURES 39–54. E. pomeranica. 39–43. LM images; 44–46. SEM images; 44. External valve view; 45. Terminal ends of external valve; 46. Terminal ends of internal valve. Figs 47–54: E. michaelis. 47–51. LM images; 52–54. SEM images; 52. External valve view; 53–54. Terminal ends of external valve. LM scale bars, 10 μm.

FIGURES 55–67. E. pseudogroenlandica. 55–62. LM images; 63–67. SEM images; 63. External valve view; 64. Internal valve view; 66. Terminal ends of external valve; 65, 67. Terminal ends of internal valve, arrow show a rimoportula. LM scale bars, 10 μm.

FIGURES 68–79. E. superpaludosa. 68–74. LM images; 75–79. SEM images; 75. External valve view; 76–78. The ends of the raphe; 79. Areolae and velum. LM scale bars, 10 μm.

FIGURES 2–18. E. mugecuo sp. nov.. 2–13. LM images; 6. Holotype; 14–18 SEM images; 14. External valve end; 15. External valve view; 16. Internal valve view; 17–18. Terminal ends of internal valve, arrow show a rimoportula. LM scale bars, 10 μm.