Distribution and Ecology of Diatoms in Thamirabarani River between Papanasam and Kallidaikurichi, Tirunelveli District, Tamil Nadu, India

1. PERIYAR UNIVERSITY
(NAAC A++ GRADE - STATE UNIVERSITY – NIRF RANK 63 – ARIIA RANK 10
SALEM – 636 011
TAMILNADU, INDIA
DEPARTMENT OF GEOLOGY
(DST-FIST SPONSORED)
Mr R. SARAN RENGARAJ
Reg. No.: P21GEO1028
Under the Guidance of
Prof. Dr. R. VENKATACHALAPATHY, M.Sc., M.Phil., Ph.D.,
Professor of Geology, Director-Alumni Association
Distribution and Ecology of Diatoms in
Thamirabarani River between Papanasam and
Kallidaikurichi, Tirunelveli District,
Tamil Nadu, India

2. INTRODUCTION
 Diatoms are microscopic unicellular algae that live in marine or
freshwater algae belongs to phylum Chrysophyta having cell walls
containing silica. They are the only organism on the planet with cell
walls composed of transparent, opaline silica. Diatom cell walls are
ornamented by intricate and striking patterns of silica.
 Diatoms have light-absorbing molecules (chlorophylls a and c) that
collect energy from the sun and turn it into chemical energy through
photosynthesis.
 Nearly all diatoms are microscopic - cells range in size from 2 µm to 500
µm (= 0.5 mm). The diatom distribution in rivers can reflect the
combined effects of environmental gradients and reveal health of river
ecosystems
 Diatoms have been extensively used as great indicators of environmental
changes due sensitivity to the environmental changes .

3. Application of Diatoms in environmental studies
 The relative abundance of diatom species is used as the most valuable
characteristics of diatom assemblages for bio-assessment of river health.
 Due to their rapid response to environmental changes and dynamics,
deterioration of water quality especially from the impacts such as nutrients
enrichments, acidification and metal contamination. Diatoms have been used
widely for bio-monitoring of aquatic ecosystem.
 Each species has specific tolerance, habit and habitat, nutrients and ecology
According to Von Haeckel who coined term ecology studies relationship of
organism have respect to each other and their natural environment.
 The various principle that governs relationship between the organisms and
environment are called Ecology
Ecology and its relationship defines in “The ecology of nature”(1869)
Organism (Diatoms ) Ecology Environment

4. Figure.1.Sample locations in the Study area
Tirunelveli

5. Table.1 Sample locations of the Study area
The study area starts from the upper course river Thamirabarani starting from
Papanasam to Kallidaikurichi.

6. Objective
 To record the diatom taxa present in the study area
 To study the distribution of diatom taxa
 To determine the Physio-chemical parameters
 To determine the Water Quality Index (WQI)
To understand the environment and their correlation

8. Collection of Samples
Twenty four (24) macrophytes samples were collected from six (6)
different locations in the study area during winter (December 2022) and
summer (March 2023) seasons. Samples were collected in zip-lock type
plastic bags from all obtainable habitats such as plants (epiphytic). Epiphytic
samples were taken by brushing the undersurfaces and petioles of at least
five plant leaves and roots. In all studies, diatom samples were preserved in
formaldehyde (4%).
Fig 1. shows Diatoms growing thickly around submerged tree branches Fig 2. shows
the film of diatoms to be found on the submerged stems (epiphytic samples)
1 2

9. Preparation of Permanent slides & processing
 The preserved periphyton was mixed well to break up attached diatoms and to
suspend the algae. Approximately 10 ml of this mixed sample was transferred into
an acid washed 100 ml Pyrex Beaker. To each beaker, an equal volume (10-15 ml)
of concentrated Hydrogen peroxide (H2O2) and Nitric acid (NHO3) were added.
The beakers were placed on a hot plate
 The final 'cleared' diatom samples an ash colored material is mounted in a
mounting medium D.P.X mounting with a refractive index close to 1.4 and placed
on a hotplate until the solvent in the medium evaporates.
 The slide is cooled immediately, by removing from the hotplate. The diatom slide
thus obtained is permanent

10. Photomicrographs
 The cleaned cells in permanent slides are observed under 40X or oil immersion
(100X) and photographed using Euromax polarizing microscope (make by
Holland and model no. ME 2885) in the Advanced Micropaleontology
Laboratory, Department of Geology, Periyar University, Salem.
Analysis Microscopes notes in the Advanced Micropaleontology Laboratory,
Department of Geology, Periyar University, Salem.

11. Identification of Diatoms
The Identifications could have done by the following referred Books
The Diatoms, Biology & Morphology of the Genera” is followed, Taylor et
al. (2007)
 An Illustrated Guide to Common Diatom of Peninsular India” are widely
used along with the published literatures of Venkatachalapathy and
Karthikeyan (2014).
Marco CANTONATI, Martyn G.KELLY & Horst LANGE-BERTALOT “
Freshwater Benthic Diatoms of central Europe : Over 800 Common species
used in Ecological Assessment

12. Checklist of diatoms taxa recorded in the study area

13. Diatom assemblage
A total of 63 diatom taxa belonging to 30 genera were recorded in the study area. They
are as follows: Achnanthes Inflata, Achnanthidium Exiguum, A. Minutissimum Amphora
copulata, Aulacoseira ambigua, A. granulata, Bacillaria paxillifera, Caloneis Bacillum, C.
silicua Cocconeis Placentula, Cyclotella Meneghiana, Cymbella tumida, C. turgidula,
Cymbopleura sublanceolata, Diadesmis Confervacea, Diploneis smithi, Discostella Stelligera,
Encyonema Hustedtii, E .mesianum, E. minutum, E. neogracile, E .Perminutum, E. Silesiacum, E.
Vulgare, , Eunotia bilunaus, E. incisa E. minor, E. zasuminensis Fragilaria Pararumpens, F. ulna,
Frustularia crassinervia, Gomphonema Affine, G. Augur, G. Exilissium, G. Gracile, G.
Graciledictum, G. Lagenula, G. Parvulum, G. pseudo augur, G. spiculoides, Melosira Varians,
Navicula Cryptotenella, N. Erifuga, N. Notha, N. radiosa, N. Rostellata, Nitzchia Clausii, N.
Palea, Oricymba Japonica, Pinnularia Acrosphaeria, P. ambalis, P. divergens, P. Subcapitta,
Placeneis Clementis, P. Constans, Rhopalodia Gibba, R. Gibberula, Sellaphora Pupula, Seminavi
strigosa, Staurosirella Pinnata, Surirella leyana, Triblionella levidensis and Ullaria ulna.

14. Location wise distribution of diatoms taxa
Papanasam:
The following diatom taxa are recorded: Aulacoseira ambigua,
Aulacoseira granulata, Discostella stelligera, Ulnaria ulna.
Vickramasingapuram:
The following diatom taxa recorded: Aulacoseira ambigua, A.
granulata, Bacillaria paxillifera, Diadesmis confervacea, Discostella
stelligera, Gomphonema gracile, G. spiculoides, G. parvulum, G.
pseudoaugur, Trybilonella levidensis.
Sivanthipuram:
The following diatom taxa recorded: Aulacoseira ambigua, A.
granulata, Diadesmis confervacea, Eunotia incise, Fragilaria Pararumpens,
Gomphonema gracile, G. lagenula, Navicula radiosa.

15. Aladiyur:
The following diatom taxa recorded: Aulacoseira ambigua, A. granulate,
Diadesmis confervacea, Discostella stelligera,, Encyonema Silesiacum and
Staurosirella pinnata.
Ambasamuthiram:
The following diatom taxa recorded: Aulacoseira ambigua, A. granulata,
cocconeis placentula, Discostella stelligera, Encyonema hustedtii, Gomphonema
lagenula, G. pseudoaugur and Pinnularia ambalis.
Kallidaikurichi:
The following diatom taxa recorded: Aulacoseira ambigua, A. granulate,
Bacillaria paxillifera, cocconeis placentula, Cymbella tumida, Diadesmis
confervacea Discostella stelligera, Encyonema hustedtii and Staurosirella pinnata.
Cont…

16. Index : A b u n d a n c e
C o m m o n R a r e
7
4-7 <
>
3
Table 2. Distribution of Diatoms taxa in Winter December 2022).

17. Table 3. Distribution of Diatoms taxa in Summer March 2023.
Index : A b u n d a n c e
C o m m o n R a r e
7
4-7 <
>
3

18. VALUE – NFS-WQI WATER QUALITY
90-100 Excellent
70-90 Good
50-70 Medium
25-50 Bad
0-25 Very bad
Table 4: Water Quality Value (NFS-WQI) Calmuc et al. 2018
S. No. LOCATIONS
WATER
QUALITY
INDEX
WATER QUALITY
1 Papanasam 49 Bad
2 Vickramasingapuram 40 Bad
3 Sivanthipuram 49 Bad
4 Aladiyur 48 Bad
5 Ambasamuthiram 54 Medium
6 Kallidaikurichi 55 Medium
Table 5: Water Quality Index Values in winter

19. S. No. LOCATIONS WATER QUALITY INDEX
WATER
QUALITY
1 Papanasam 49 Bad
2 Vickramasingapuram 46 Bad
3 Sivanthipuram 46 Bad
4 Aladiyur 49 Bad
5 Ambasamuthiram 56 Medium
6 Kallidaikurichi 61 Medium
Table 6: Water quality index values in summer season.

20. Result and Discussion
 In this present study revealed that water quality assessment, based on the
diatom assemblages and water quality index following results had been
obtained. The water quality index values (40-50) were recorded in locations
Papanasam, Vickramasingapuram, Sivanthipuram, and Aladiyur indicated
polluted water. It is observed that the main cause of untreated waste water from
industries discharge on surface water and anthropogenic activities. Whereas
locations Ambasamuthiram and Kallidaikurichi were recorded water quality
index values of (54-61) indicate moderate-meso eutrophic water. In the present
study an attempt had been made to evaluate the applicability of water quality
index assessment in Thamirabarani River in part of Tamil Nadu, South India.

21. Summery and Conclusion
 A Present study recorded the dominant presence of diatom taxa viz. were recorded
such as Aulagoseira ambigua, A. granulate, Diadesmis confervacea,
Gomphonema lagenula, G. parvulum, G. pseudoaugur, Trybilonella levidensis
and Bacillaria paxillifera, ulnaria ulna during winter and summer seasons at
Papanasam, Vickramasingapuram, Sivanthipuram, Aladiyur.
 The study of diatom taxa and water quality index indicates moderate to eutrophic
condition of water with values 40 to 50 at Papanasam, Vickramasingapuram,
Sivanthipuram, Aladiyur in both winter and summer seasons, may be due do
industrial wastages and anthropogenic activities.

22. Cont…
 However, the analysis of diatom taxa and water quality index indicates meso
eutrophic to oligotrophic conditions of water with values 54 to 61 at
Ambasamuthiram and Kallidaikurichi locations in both seasons. The diatom taxa
such as Gomphonema lagenula, ulnaria ulna, Discostella stelligera, cocconeis
placentula, Staurosirella pinnata, Seminavis strigosa, Gomphonema
pseudoaugur, Cymbella tumida are recorded in these locations.
 The diatom taxonomic distribution studies help in the assessment of diatom
potential and water quality index can be a dependable method for evaluation
environmental effects in the Thamirabarani River.

23. 1. Achnanthes inflata
2. Amphora copulata
3. Aulacoseira ambigua
4. A. granulata
5. Bacillaria paxillifera
6. Caloneis Bacillum
7. Cocconeis placentula
8. Cyclotella meneghiniana
9. Cymbella tumida
10. Diadesmis confervacea
PLATE I
Scale :10 µm
All images are 40 X

24. 1. Diploneis smithi
2. Discostella stelligera
3. Encyonema mesianum
4. Encyonema minutum
5. Encyonema noegracile
6. Encyonema Silesiacum
7. Eunotia bilunaris
8. Eunotia minor
9. Fragilaria Pararumpens
10. Fragilaria ulna
Scale :10 µm
PLATE -II
All images are 40 X

25. 1. Frustulia crassinervia
2. Gomphonema affine
3. Gomphonema augur
4. Gomphonema exilissimum
5. Gomphonema gracile
6. Gomphonema graciledictum
7. Gomphonema pseudoaugur
8. Gomphonema spiculoides
9. Melosira varians
10. Navicula rostellata
PLATE III
Scale :10 µm
All images are 40 X

26. PLATE IV
1.Nitzschia clausii
2.Nitzschia palea
3. Oricymba japonica
4. Pinnularia acrosphaeria
5. Pinnularia ambalis
6. Pinnularia divergens
7. Navicula cryptotenella
8. Navicula erifuga
9. Navicula notha
10. Navicula radiosa
Scale :10 µm
All images are 40 X

27. PLATE V
1. Rhopalodia gibberula
2. Rhopalodia gibba
3. Pinnularia subcapitata
4. Placoneis clementis
5. Placoneis constans
6. Staurosirella pinnata
7. Sellaphora pupula
8. Seminavis strigosa
9. Surirella leyana
10. Triblionella levidensis
11. Ulnaria ulna
Scale :10 µm
All images are 40 X

28. Field Photos Sample Collection of the study area
Sample processing & laboratory photographs

29. Thanking You