Cymbella biseriata sp. nov. - a unique living species of Cymbella Agardh (Bacillariophyceae) with biseriate striae Author Videska, Anastasija Author Zaova, Dušica Author Naumovska, Hristina Author Kochoska, Hristina 0000-0001-5245-036X hristinakochoska @ yahoo. com; https: // orcid. org / 0000 - 0001 - 5245 - 036 X hristinakochoska@yahoo.com Author Mitic-Kopanja, Danijela 0000-0001-5187-5892 mitickopanja @ yahoo. com; https: // orcid. org / 0000 - 0001 - 5187 - 5892 mitickopanja@yahoo.com Author Levkov, Zlatko 0000-0002-1184-2356 zlevkov @ pmf. ukim. mk; https: // orcid. org / 0000 - 0002 - 1184 - 2356 zlevkov@pmf.ukim.mk text Phytotaxa 2022 2022-09-06 561 1 41 52 http://dx.doi.org/10.11646/phytotaxa.561.1.4 journal article 138347 10.11646/phytotaxa.561.1.4 7b11c983-529a-4e2b-a8ad-e9b79f7612ea 1179-3163 7052809

TABLE 1: Morphological features and measurments of Cymbella biseriata sp. nov. and comparison with similar Cymbella species.

Taxon	Valve length Valve width Striae/ 10			Areolae/ 10	Striae type	Stigma	Central area	Apices	APF	Reference
	(in µm)	(in µm)	µm	µm
C. biseriata sp. nov. 29–38		7–9	12–15	40–50	Biseriate	4–7	Nearly absent or	Slightly	Absent	This study
							slight broaden of	subcapitated
							axial area
C. cantonatii	30–55	10–13	10–13	29–33	Uniseriate	4–8	More pronounced	Rounded, not	Absent	Lange-Bertalot
							on dorsal side	distinguished from		in Krammer
								valve body		(2002)
C. compacta	28–76	12–15	9–12	18–24	Uniseriate	4–8	Lacking or not well	Rounded, only in	Absent	Østrup (1910)
							expressed	large specimens
								distinguished form
								valve body
C. subhelvetica	33–70	8.5–11	9–11	20–25	Uniseriate	4–8	Lacking on dorsal	Narrowly rounded, Absent		Krammer
							side, not well	not or barely		(2002)
							expressed on	distinguished from
							ventral side	valve body
C. lange-bertalotii	38–100	10–16	8–12	18–24	Uniseriate	4–8	Lacking or not well	Narrowly rounded, Absent		Krammer
							expressed	not or barely		(2002)
								distinguished from
								valve body
C. helvetica	75–154	18–26	6–8	14–18	Uniseriate	Up to 10	Roundish to	Rounded,	Absent	Kützing (1844)
							elliptical longest at	not or barely
							apical axis	distinguished from
								valve body
C. balatonis	78–120	24–30	7–8	15–17	Uniseriate	3–8	Elliptical or	Narrowly rounded, Absent		Schmidt et al.
							rhomboidal,	not or barely		(1874–1959)
							longest at apical	distinguished from
							axis	valve body
C. suavis	81–120	28–32	6–7	8–13	Uniseriate	Not well	Elliptical, longest	Rounded to	Absent	Pantocsek
						observed in LM at apical axis		moderately convex		(1892)
C. oligocenica	60–66	23–24	11–12	12–14	Uniseriate	3–4	Very small, more	Rounded, not	Absent	Krammer
							pronounced on	distinguished from		(2002)
							dorsal side	valve body
C. ohridana	59–103	18–26.6	10–12	16–18	Uniseriate	8–12	Asymmetrical to	Bluntly rounded,	Absent	Levkov et al.
							elliptical, more	not protracted		(2007)
							developed dorsally
C. duplopunctata	125–150	26–32	7–9	12–15	Biseriate	9–12	Large, orbicular,	Not protracted,	Present	Krammer
							1/3–1/2 the width	broadly rounded		(2002)
							of the valve
C. buechleri	175	32	6–9	12–13	Biseriate	5	Large, orbicular,	Rounded, not	Present	Krammer
							1/3–1/2 the width	protracted		(2002)
							of the valve