Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 October 2023 | 15(10): 24144–24147
ISSN 0974-7907
(Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.8264.15.10.24144-24147
#8264 | Received 10
November 2022 | Finally accepted 07 October 2023
Rare desmid genus Bourrellyodesmus Compère (Chlorophyceae: Desmidiales: Desmidiaceae) in India with description of a new species (Bourrellyodesmus indicus Das & Keshri sp. nov.) from eastern
Himalaya, India
Debjyoti Das 1 &
Jai Prakash Keshri 2
1 Department of Botany, Khalisani Mahavidyalaya, Chandannagar, West Bengal 712138, India.
2 Phycology Laboratory, CAS in
Botany, The University of Burdwan, Burdwan, West Bengal 713104, India.
1 debjyotidas72@yahoo.in,
2 keshrijp@gmail.com (corresponding author)
Editor: Anonymity requested. Date of publication: 26 October 2023 (online & print)
Citation: Das, D. & J.P. Keshri
(2023). Rare desmid genus Bourrellyodesmus Compère (Chlorophyceae: Desmidiales: Desmidiaceae) in
India with description of a new species (Bourrellyodesmus
indicus Das & Keshri sp. nov.)
from eastern Himalaya, India. Journal of Threatened Taxa 15(10): 24144–24147. https://doi.org/10.11609/jott.8264.15.10.24144-24147
Copyright: © Das & Keshri 2023. Creative Commons Attribution 4.0
International License. JoTT allows unrestricted use, reproduction, and
distribution of this article in any medium by providing adequate credit to the
author(s) and the source of publication.
Funding: UGC, New Delhi.
Competing interests: The authors declare no competing interests.
Acknowledgements: Authors acknowledge to UGC, New
Delhi for financial support to carry out this investigation & Head of the
department of Botany, The University of Burdwan for laboratory facilities.
Special thanks are due to The Home Department, Govt. of Sikkim for various help
and Forest Department, Govt. of Sikkim.
According to Algaebase
(2022) Bourrellyodesmus Compère
is represented by nine species. The genus was established by Compère (1976) to accommodate certain species of Arthrodesmus Ralfs. Compère (1976)
however reconstructed just one species of Arthrodesmus
Ralfs (A. heimii Bourrelley) to Bourrellyodesmus
heimii (Bourrelley) Compère on the basis of the presence of thickened membrane
in the middle of the semicells, covered with warts or
scrobiculations and having unispinous
angles put as diagnostic character of the genus (Compère
1976). Later on Bicudo & Compère
(1978) proposed four more combinations, viz., B. excrescens
(Scott & Grönblad) C.Bicudo & Compère, B.
jolyanus (C. Bicudo
& Azevedo) C.Bicudo & Compère,
B. spechtii (Scott & Prescott) C.Bicudo & Compère, and B.
sumatranus C.Bicudo
& Compère as good species under this genus.
Faustino & Bicudo (2004) added another species to
this list, namely, B. guarrerae Faustino &
C.Bicudo from São Paulo,
Brazil. Ramos et al. (2022) redesignated two taxa of Xanthidium Ehrenberg ex Ralfs
viz. X. tenuissimum Kurt Förster
var. amazonense Kurt Förster
and Xanthidium tenuissimum
Kurt Förster var. constrictum
Kurt Förster to B. amazonensis
(Kurt Förster) G. Ramos, C.Bicudo & Moura and B. constrictus
(Kurt Förster) G. Ramos, C. Bicudo
& Moura, respectively on the basis of their observations about the taxa.
The characters of the taxa actually tallies with the
genus Bourrellyodesmus. This year
Santos et al. (2022) described a new species namely as B. comperei Santos & Moura from Caatinga domain, northeastern Brazil.
During our extensive
investigations to the desmid flora of Sikkim Himalaya (Das & Keshri 2016), we had observed this curious genus. Although
this taxon although resembles Bourrellyodesmus,
it does not tally with any described species of the genus. It is also
interesting that this genus is being recorded for the first time from the
Indian subcontinent.
To the native people of Sikkim
mountain lakes are of enormous value for their existence. They worship these
water bodies and so the live forms inhabit therein. Among several lakes present
in this state, ‘Betang-cho’ or ‘Elephanta
lake’ is unique with respect to its water microflora. Above 150 taxa of phytoplanktons were identified from a single lake (Das
& Keshri 2012, 2016). This high
altitude lake is situated in East Sikkim District with an altitude about
4,150 m from sea level and between 27.3337–27.3261 E & 88.8439–88.8487 N.
Being situated in such high altitude the area nearby the lake is almost bare.
Only a few small herbs and grasses grow here and there. A few algal masses grow
in benthic or semi-benthic conditions. Phytoplankton frequently found along
with these aquatic or semi-aquatic weeds. In the winter season the lake is
completely covered with ice.
Samples were collected simply by
hand from different accessible spots of the lake. Totally, nine collections
were made. Several samples, i.e., visible algal mat or lumps floating on the
surface of the water and also in association with aquatic herbs were collected
and immediately fixed on the spot by 5% formalin aqueous solution. In another
bottle water sample was preserved with 1% Lugols’
iodine to study the microscopic phytoplanktons.
Detailed ecological observation recorded in field notebook with water
temperature and pH of the water measured by standard thermometer and standard
universal pH indicator of Merck (Das & Keshri
2016). Observations were made in the laboratory under Olympus GB compound
microscope with GWF as mountant medium (Bando 1988).
Photomicrographs were also taken using Zeiss Axiostar
plus research microscope with Nikon SLR camera attachment system.
Bourrellyodesmus indicus Das & Keshri
sp. nov.
(Image 1 A–C)
Material examined
Holotype: No. DD-380(c), 06
November 2009, India, Sikkim, East Sikkim, Betangcho
Lake, (27.3337–27.3261 N & 88.84397–88.8487 E), deposited in the Herbarium
of Phycology Section, CAS in Botany, The University of Burdwan, West Bengal
(BURD), coll. D. Das & J.P. Keshri.
Cells 1.1-1.3 times broader than
long, semicells elliptical, apical margin rounded,
curved downward continued to the spines, basal margin convex, angles with 1
solid convergent, short spine; sinus deep, open, V-shaped; cells elliptical in
apical view, cell wall minutely punctate, each semicell
with a lump of small facial granules in the centre; chloroplast and pyrenoid
not observed; zygospore was also not found. Cell dimension: length 34–36 μm, width without spines 30–32 μm,
with spines 39–41 μm. isthmus 11–12 μm. spines length 4–6 μm.
Habitat: New taxa rarely found in
the study area, in association with other filamentous algae Spirogyra
attached to the surface of the submerged aquatic plants. pH: 6, water
temperature 10ºC at the time of collection.
Differential diagnosis: In
respect to shape of the semicell present taxa
resembles B. excrescens (Scott & Grönblad) C.Bicudo
& Compère and B. heimii
(Bourrelley) Compère as
these species possess elliptical semicells with rounded
or convex apex. Although B. guarrerae
Faustino & C.Bicudo
possess elliptic or circular semicells but lateral
spines are subparallel here and also cell dimension is smaller. B. jolyanus (C.Bicudo
& Azevedo) C.Bicudo & Compère
despite having elliptical semicells but also possess
rounded granules at the upper lateral margins which are absent in B. indicus.
Our taxa differs from B. excrescens (Scott & Grönblad)
C.Bicudo & Compère in having a large emarginate tubercle on the faces
of both sides of the semicells and downwardly curved
spines.
B. heimii shows close resemblance to the
present taxa having similar semicell shape and nature
of the spines. Main dissimilarities of B. heimii
have been noticed is the presence of just a lump of small facial granules on each
side of semicell in place of several large granules
alternating with triangular scrobiculations. B.
indicus is also smaller.
A comparative account of the taxa
is appended in Table 1.
Genus Bourrellyodesmus
is being reported for the first time form India as
well as eastern Himalayan alpine region. As this region is among the major
hotspots of the world, further and more detail observations my reveal more such
plant sciences.
Table 1. Comparison between
existing species of Bourrellyodesmus with the
proposed species.
|
B. indicus sp. nov. |
B. jolyanus (C.E.M.Bicudo & Azevedo) C.E.M.Bicudo
& Compère |
B. guarrerae
Faustino & C.E.M.Bicudo |
B. heimii (Bourrelley) Compère |
B. excrescens
(Scott & Grönblad) C.E.M.Bicudo & Compère |
B. sumatranus
C.E.M.Bicudo & Compère |
B. spechtii
(A.M.Scott & Prescott) C.E.M.Bicudo & Compère |
B. comperei M.A. Santos & C.W.N. Moura |
B. constrictus (Kurt Förster) G.J.P. Ramos, C.E.M. Bicudo & C.W.N. Moura |
B. amazonensis (Kurt Förster) G.J.P. Ramos, C.E.M. Bicudo & C.W.N. Moura |
|
|
Elliptic |
Elliptic |
Elliptic to sub-circular |
Elliptic |
Elliptic |
Pyramidal with convex apex |
Subrectan-gular |
Trapiziform |
Trapiziform |
Hexagonal |
Shape of the semicells |
|
No ornamentation |
2 rounded granules in each side of the semicell |
No ornamentation |
No ornamentation |
No ornamentation |
No ornamentation |
No ornamentation |
1 tiny granules in each side of the semicell |
No ornamentation |
No ornamentation |
Ornamentation on the upper lateral angles |
|
Open, V-shaped |
Open, V-shaped |
Open, acute angled |
Open, V-shaped |
Open, V-shaped |
Closed |
Closed |
Closed, deep |
Open, V-shaped |
Open, shallow |
Sinus |
|
Blunt, convergent |
Acute, long, convergent |
Acute, subparallel |
Blunt, convergent |
Short, acute, parallel to slightly divergent |
Short, acute, parallel to slightly convergent |
Long, vertical |
Short, blunt, downward |
Short, blunt, parallel |
Short, blunt, parallel |
Lateral spine |
|
Lump of small facial granules |
Small median swelling, single |
Small rounded granules, single |
Large granules with triangular scrobiculation,
several in number |
Rounded tubercle, single |
Rounded median protuberance, single |
Small intumescence, single |
Small intumescence, single |
Small rounded granule, single |
Small rounded granule, single |
Ornamentation on the face of the semicell |
For image
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References
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