Gyrosigma dongtingense sp. nov. (Bacillariophyta) from Dongting Lake, China Author Yi, Man-Qi 0000-0002-0503-0626 College of Biology and Environmental Sciences, Jishou University, Jishou 416000, China 810847692@qq.com Author Liu, Bing 0000-0002-8516-325X College of Biology and Environmental Sciences, Jishou University, Jishou 416000, China jsulb@outlook.com Author Rioual, Patrick 0000-0001-9491-9197 Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, P. O. box 9825, Beijing 100029, China & CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, China prioual@mail.iggcas.ac.cn Author Lei, Qin 0009-0002-6825-9433 College of Biology and Environmental Sciences, Jishou University, Jishou 416000, China 339096051@qq.com Author Ma, Yi-Dan 0009-0005-0636-4168 College of Biology and Environmental Sciences, Jishou University, Jishou 416000, China 1761534033@qq.com text Phytotaxa 2024 2024-04-11 644 2 113 123 http://dx.doi.org/10.11646/phytotaxa.644.2.3 journal article 300707 10.11646/phytotaxa.644.2.3 1efa6cc0-6313-420f-9396-da89584db938 1179-3163 13214603

TABLE 1. Comparisons between Gyrosigma dongtingense sp. nov. and similar species.

Feature	G. dongtingense	G. crassum	G. acuminatum	G. kuetzingii	G. strigilis
Valve outline	Moderately sigmoid	Moderately sigmoid	Moderately sigmoid	Sigmoid	Moderately sigmoid
Valve length (μm)	161–218	130–170	70–180	90–150	250–380
Valve width (μm)	24–29	24–27	12–24	12–15	27–32
Transverse stria in 10 μm	12–14	13–14	18–23	21–23	11–14
Longitudinal stria in 10 μm	16–18	24–27	19–24	24–27	15–16
Central area	Quadrangle, rotated	Elliptic	Oval, not rotated	Oval, not rotated	No data
Outer proximal raphe fissures	Oppositely deflected	No data	Oppositely deflected	Oppositely deflected	No data
Inner proximal raphe fissures	T-shaped	No data	Simple, straight	No data	T-shaped
Isomorphic or dimorphic species	Isomorphic	No data	Dimorphic	Dimorphic	Isomorphic
Reference	This paper	Meister 1935	Sterrenburg 1995; Reid 2008	Sterrenburg 1997	Krammer & Lange-Bertatlot 1986; Sterrenburg 1993; Maidana & Romero 1995