全 文 ：Received 27 Oct. 2003 Accepted 22 Dec. 2004
Supported by the State Key Basic Research and Development Plan of China (G1999043706, 2001CB409701) and the National Natural
Science Foundation of China (30270118).
* Author for correspondence. Tel: +86 (0)592 2181386; E-mail: .
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Acta Botanica Sinica
植 物 学 报 2004, 46 (7): 788-792
Nanoneis, a Newly Recorded Diatom Genus from China
and Nanoneis longta sp. nov.
LI Yang, GAO Ya-Hui*, CHEN Chang-Ping, LIANG Jun-Rong
(School of Life Sciences, Xiamen University, Xiamen 361005, China)
Abstract: Nanoneis was identified as a newly recorded diatom genus for China under transmission
electron microscope (TEM) in the water samples from the East China Sea and Huanghai Sea (Yellow Sea).
The valves of this diatom are bilaterally symmetrical and have a raphe extending through the middle of the
valve from one pole to near the center. The raphe of the opposite valve on the same cell extends from the
other pole to near the center. The alveoli or ribs of the valve face continue around the valve mantle. Two
species were described in this paper, including Nanoneis longta sp. nov. as a new species and Nanoneis
hasleae as a new recorded species for China. They have some distinctly different characteristics in the
shape of valve surface, the ratio of length to width and the density of alveoli or ribs on valve face. Detailed
description of the taxonomic characteristics with TEM photographs of these two species and their eco-
logical distributions were given in this paper. N. longta sp. nov.: cells are narrowly linear in valve view and
bilaterally symmetrical with convexity being present in the apices and in the middle of the valve. Cell length
10-12 mm, width 1.0-1.5 mm. The ratio of length to width is about 10:1. Valve structure consisting of
thickened ribs perpendicular to the apical axis alternating with thin areas, alveoli, in the greater length of
the valve. Ribs and alveoli radically arranged in apical parts of valves. The density of the transapical ribs is
approximately 60 in 10 mm. A simple raphe located in the middle of valve, extending from one pole to a point
near to the median part of the valve. The opposite valve on the same cell with the raphe extended from the
opposite pole to near the center. The specimens were collected from a 20-m layer at latitude 29º 6 31 N,
longitude 126º 57 72 E, in Nov., 2000.
Key words: East China Sea; Huanghai Sea; nanodiatom; Nanoneis ; Nanoneis longta sp. nov.
Marine nanodiatoms have been either frequently un-
derestimated or overlooked in phytoplankton investiga-
tions due to their small size (usually 2-20 µm), which will
mostly pass through a regular phytoplankton net of 60-70
µm pore size. But, it has been validated that nanodiatom is
an important primary producer in marine waters and makes
a great contribution to diatom biomass and species diversity,
especially in coastal waters (Hallegraeff, 1981; 1984; Gao et
al., 1992; Cheng and Gao, 1993; Cheng et al., 1993). This
conclusion has been embodied in several studies concern-
ing nanodiatom taxonomy from coastal waters of China
such as Xiamen Harbour (Gao and Cheng, 1992; Cheng and
Gao, 1993), coastal waters of Fujian Province (Cheng et al.,
1993; Liu et al., 1994), Jiaozhou Bay (Gao and Jiao, 1995;
Jiao and Gao, 1995), the north area of South China Sea (Guo
et al., 1999a; 1999b) and Hong Kong waters (Gao et al.,
2003).
With the meaning of a very small valve surface and boat-
like shape, the genus Nanoneis was erected by Norris in
1973 which was emended from genus Anisosiraphe (Norris,
1972; 1973). The special characteristics of this genus are
the extraordinary raphe extending from one pole to near the
center and the raphe of the opposite valve on the same cell
extending from the opposite pole to near the center. The
first species of genus Nanoneis was denominated as N.
hasleae named after Hasle G. R. for her extensive contribu-
tion to our understanding of pennate diatoms in oceanic
plankton (Norris, 1973). Publications about Nanoneis, which
has been a monospecific genus, including N. hasleae are
few.
In a preliminary investigation of nanodiatom species in
the East China Sea and Huanghai Sea (Yellow Sea), the
diatom genus Nanoneis was observed as a newly recorded
genus for China and N. longta was found as a new species.
Detailed description of the taxonomic characteristics with
TEM photographs of the genus Nanoneis and its two
species, i.e. N. hasleae, N. longta and their ecological char-
acteristics and distribution were made in this paper.
LI Yang et al.: Nanoneis, a Newly Recorded Diatom Genus from China and Nanoneis longta sp. nov. 789
1 Materials and Methods
One or two litres of water samples were collected from
each sampling station in the East China Sea and Huanghai
Sea during the cruises carried out from Oct. and Nov., 2000
and Mar. and Apr., 2001. All water samples were fixed with
Lugo’s solution in situ and brought back to the laboratory.
Samples were concentrated, acidized and rinsed with dis-
tilled water to neutrality before being observed and photo-
graphed on carbon-coated copper under the JEM-100CXⅡ
transmission electron microscope (Cheng et al., 1993).
2 Results and Discussion
Nanoneis has been a monospecific genus previously
only including N. hasleae. In this paper, two species were
described, including N. longta sp. nov. as a new species
and N. hasleae as a new recorded species for China.
Nanoneis R. E. Norris
Nanoneis Norris 1973, Figs.1-6; Hasle and
Syvertsen 1997, p. 271, pl. 60.
Synonymy: Anisosiraphe Norris 1972, nom.
nud. Figs.1-4.
Cells broadly elliptical to linear, valve surfaces slightly
convex to flat or concave, with the concavity present be-
tween the apices and the middle part of the valve (Hasle
and Syvertsen, 1997). Valves symmetrical about apical axis.
Special raphe in the middle of the valve extending from one
pole to near the center and raphe of opposite valve on the
same cell extending from the opposite pole to near the center.
Alveoli or ribs present on the valve surfaces except the
axial area (Norris, 1973).
Cells occurring in irregular chains with a short overlap
of cell ends, connected to another so that the raphe on one
valve touches the pseudo-raphe on the valve of the adja-
cent cell (Norris, 1973; Hasle and Syvertsen, 1997).
The species of Nanoneis are warm in behaviour and are
mostly distributed in subtropical and tropical open oceanic
waters.
Nanoneis hasleae R. E. Norris (Pl. 1, Fig.1)
R. E. Norris 1973, p. 321-325, Figs.1-6; Hasle and
Syvertsen 1997, p. 270-271, pl. 60.
Synonymy: Anisosiraphe hasleae Norris 1972,
nom. nud. Figs.1-4.
Cells broadly elliptical to fat-shortly linear in valve view.
Cell length 5-7 µm, width 1.0-1.5 µm. The ratio of length to
width is about 4:1. The concavity presents between the
broadly rounded apices and the middle part of the valve.
Alveoli or ribs rank on the valve surface except the axial
area, arranged in apical parts radially and perpendicularly
to apical axis in the greater length of valves. There are 40-
50 transapical ribs in 10 µm.
A simple raphe extending from one pole to a point near
to the median part of the valve. Opposite valve with the
raphe extending from the opposite pole (Norris, 1973).
Cells were connected with each other in irregular chains
by a short overlap of valve ends (Norris, 1973). But, we
have not seen the colony.
N. hasleae is a warm species. The first specimen ob-
served by Norris was collected from the Indian Ocean in
1967. Dr. Hasle found several frustules similar to N. hasleae
at latitude 30º 55 7 S, Longitude 30º 20 5 E (near Durban,
South Africa), on Aug. 26, 1958 and in a collection of plank-
ton made near La Jolla, California, on Aug. 22, 1967 (Norris,
1973). Our specimens were collected from a 20-m layer at
latitude 29º 6 31 N, longitude 126º 57 72 E, in Nov., 2000.
Nanoneis longta Li et Gao sp. nov.
（Pl. 1, Figs.2-6）
Cellullae valvae visae longae lineares. Facies exteriors
paullulum convexae in apices et medias valvae praesens.
Raphe in parte valvae media ex polo uno ad centrum
extendens, raphe valvae opposite a polo opposito fere ad
centrum extendens. Alveolae praesentes in valvas,
parallelae dispositae propartibus majoribus valvarum et ra-
diatae dispositae in polas.
Longitudo cellulae 10-12 µm. Latitudo 1.0-1.5 µm,
admodum 60 costae transapicales in 10 µm.
Habitat in mare East China Sea
Typus: 0011G10L20, Facultas Biologica Universitatis
Xiamensis
Cells are narrowly linear in valve view and bilaterally
symmetrical with convexity presenting the apices and the
middle of the valve. Cell length 10-12 µm, width 1.0-1.5 µm.
The ratio of length to width is about 10:1. Valve structure
consisting of thickened ribs perpendicular to apical axis
alternating with thin areas, alveoli, in the greater length of
the valve. Ribs and alveoli radically arranged in apical parts
of valves. The density of transapical ribs is approximately
60 in 10 µm. A simple raphe located in the middle of valve,
extending from one pole to a point near to the median part
of the valve. The opposite valve on the same cell with the
raphe extending from the opposite pole.
The specimens were collected at the same location and
time as N. hasleae, 20 m layer at Latitude 29º 6 31 N, longi-
tude 126º 57 72 E, in Nov., 2000.
Type specimens: 0011G10L20, School of Life Sciences,
Xiamen University.
Norris (1973) regarded that the longer specimens, with
one valve elliptical and the other linear and longer, be the
Acta Botanica Sinica 植物学报 Vol.46 No.7 2004790
same species with N. hasleae. But, we do not think so, as
our specimens identified as N. longta have distinctive char-
acteristics from N. hasleae (Table 1).
Firstly, the valve view of the two species are distinctly
different. N. hasleae has elliptical valve surface with the
ratio of length to width about 4:1 and the ratio of length of
raphe to length of valve about 3:10. They were 10:1 and 1:4
in the narrowly linear valve surface of N. longta
respectively. Therefore, the valve surface of N. longta is
longer in apical axis than that of N. hasleae. Secondly, the
density of ribs on the valve surface of N. longta is about 60
in 10 µm, which is higher than 40-50 of N. hasleae. Due to
those two reasons, we suggest that the longer specimens
should be ranked as a new species N. longta, which was
Figs.1-6. 1. Nanoneis hasleae. 2-6. Nanoneis longta. 2. Whole valve. 3, 5. Detail of raphe. 4. Detail of raphe and alveoli or ribs. 6.
Fragmentary valve (Scale bar =1 µm).
Table 1 The difference between Nanoneis hasleae and N.
longta
Length Width
Density of
Length/
(µm) (µm)
ribs
Width
(in 10 µm)
N. hasleae 5-7 1-1.5 40-50 4:1
N. longta 10-12 1-1.5 60 10:1
LI Yang et al.: Nanoneis, a Newly Recorded Diatom Genus from China and Nanoneis longta sp. nov. 791
named according to its typical feature of longer valve length
than N. hasleae.
Acknowledgements: We thank deceased Prof. CHENG
Zhao-Di of the School of Life Sciences, Xiamen University,
for his valuable advice concerning Nanoneis and Prof.
HUANG Bang-Qin of the Environmental Science Center,
Xiamen University, for his kind assistance in field work.
We are indebted to Dr. HOU Xue-Liang of the School of
Life Sciences, Xiamen University, for his assistance in Latin
description. Thanks are also extended to Ms. NI Zi-Mian,
Ms. XUE Ru and Mr. YANG Xiao-Dong of the Electron
Microscope Laboratory, Xiamen University, for their help
with the TEM and to Miss YU Qiu-Bo, Mr. LONG Hua and
Mr. GAO Hua for their photographic assistance.
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(Managing editor: HAN Ya-Qin)