ENVIS Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Sunday, January 17, 2021

Araniar estuary

 

Araniar estuary

 

Name of the River
Araniar
Place
Near Pulicat
District
Tiruvellore
State
Tamil Nadu
Latitude
13° 25’N
Longitude
80° 15’E
Important land marks
Pulicat
Average depth
0.3 m
Type of the Estuary
Bar-built
Water temperature
31° C
Nature of the Substratum
Hard-Muddy
Salinity
34.00 ppt
Dissolved oxygen
4.30 mg/l
Predominant Benthic fauna
Foraminiferal
Commercially important Shellfishes
Oysters
Sewage discharges
Yes

Image

Map

River Basin Map

Physico-chemical entities 

Size of foraminiferal assemblages along with some physic-chemical parameters of the Araniar river estuary

 

 Biological entities 

Average assemblage density distribution of total (Living + Dead) Foraminifera in Araniar river estuary [Occurrence: R = rare (5%), F = frequent (5-10%), C = common (10-15%), A = abundant (15%)]

 

Sl.No.

Species
Stations
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
Ammobaculites sp.
R
R
R
R
R
R
R
F
F
R
F
F
F
A
2
Ammobaculites agglutinans
R
R
R
R
R
R
F
F
F
F
C
F
C
A
3
Ammobaculites diverses
 
 
R
 
 
R
R
 
 
 
R
F
 
 
4
Ammobaculites exiguus
R
R
R
R
R
R
R
R
R
R
R
R
A
A
5
Ammomarginulina foliaceus
 
 
 
 
 
 
 
R
R
R
R
R
C
F
6
Ammonia beccarii
A
A
A
A
A
A
A
A
A
A
A
A
F
F
7
Ammonia tepida
F
A
A
F
F
F
R
R
R
F
F
F
R
 
8
Ammotium cassis
 
 
 
 
 
R
 
 
 
 
 
 
 
 
9
Amphistegina lessonii
R
 
 
 
 
 
 
 
 
 
 
 
 
 
10
Asterorotalia dentata
F
F
F
R
 
R
R
F
F
F
F
 
F
 
11
Asterorotalia trispinosa
R
 
 
 
 
 
 
C
R
 
 
 
 
 
12
Bolivina nobilis
 
R
 
R
R
 
 
 
 
R
R
 
 
 
13
Bolivina striatula
 
R
R
 
 
 
R
R
 
 
 
 
 
 
14
Cibicides labatulus
R
R
R
R
F
F
F
F
F
R
R
R
R
R
15
Elphidium adrenum
R
R
R
R
R
R
R
R
 
 
 
R
F
 
16
Elphidium crispum
F
R
R
R
F
R
R
R
R
R
F
F
 
 
17
Elphidium excavatum
R
R
 
R
R
 
R
R
R
R
R
 
 
 
18
Elphidium hispidulum
R
R
F
R
R
R
R
R
R
F
R
R
R
 
19
Florilus grateloupi
A
F
R
F
R
F
C
F
R
F
R
F
F
 
20
Florilus labrodoricum
R
 
R
 
R
R
R
R
 
R
 
R
R
 
21
Globulina gibba var globosa
 
R
R
 
 
 
 
R
 
 
 
 
 
 
22
Haplophragmoides sp.
R
R
R
R
R
F
F
A
A
A
A
F
F
R
23
Miliammina fusca
R
R
R
R
 
R
R
R
R
R
 
R
 
 
24
Miliolinella australis
 
F
R
R
 
 
 
 
 
 
 
 
 
 
25
Poroeponides lateralis
 
 
R
 
 
 
 
 
 
 
 
 
 
 
26
Pyrgo sp.
A
 
R
 
 
R
 
 
 
 
 
 
 
 
27
Quinqueloculina sp.
 
 
 
 
 
R
R
 
 
 
 
 
 
 
28
Quinqueloculina agglutinans
F
F
F
R
R
R
F
R
R
R
R
R
R
R
29
Quinqueloculina akneriana
 
F
 
 
 
 
 
 
 
 
 
 
 
 
30
Quinqueloculina bicostata
R
R
R
R
 
 
 
 
 
 
 
 
 
 
31
Quinqueloculina lamarkiana
 
R
 
 
 
 
 
 
 
 
 
 
 
 
32
Quinqueloculina parkeri
R
A
 
 
 
 
 
 
 
 
 
 
 
 
33
Quinqueloculina seminulum
F
C
F
R
R
R
R
R
R
R
 
 
 
 
34
Sigmavirgulina tartuosa
 
R
 
 
 
 
 
 
 
 
 
 
 
 
35
Siphogenerina glabra
 
 
 
 
R
R
 
 
 
 
 
 
 
 
36
Siphogenerina raphanus
 
 
 
R
 
 
 
 
 
R
 
 
 
 
37
Siphogenerina virgula
 
 
 
 
R
R
R
 
 
 
 
 
 
 
38
Spiroloculina nitida
 
R
R
 
 
 
 
 
 
 
 
 
 
 
39
Spiroloculina orbis
 
 
R
 
 
 
 
 
 
 
 
 
 
 
40
Textularia polustris
 
R
R
R
R
R
R
R
R
R
A
C
C
A
41
Triloculina terqueminana
 
F
 
 
 
 
R
R
 
 
 
 
 
 
42
Triloculina tricarinata
R
C
R
 
 
 
 
 
 
 
 
 
 
 
43
Triloculina trigonula
 
C
R
 
 
 
 
 
 
 
 
 
 
 
44
Trochammina sp.
R
R
R
 
R
R
R
R
R
R
F
F
C
A

Foraminifera

 Ammobaculites agglutinana
Ammonia beccarii var. tepida
Globigerina bulloides
Globigerinoides trilobus
Quinqueloculina agglutinata
Quinqueloculina seminula
Rectobolivina raphana
steroratalia dentata
 

Inference 

Ø The lower estuarine region is characterized by low range of variability and high abundance of foraminiferal counts, while the upper estuary by low range of variability and low faunal abundance. 
 
Ø The living assemblages have limited number of species with Ammonia beccarii being dominant in all seasons.
 
Ø Of the various ecological parameters studied salinity, pH and calcium have a close bearing on the distribution and abundance of foraminifera in the estuary.
 
References
 
Reddy and K.R. Reddy, 1982. Recent benthonic foraminifera from the Araniar river estuary, Tamil Nadu. Indian Journal of Marine Science, 11: 249–250.
 
Reddy, A.N. and K.R. Reddi, 1994. Seasonal distribution of Foraminifera in the Araniar river estuary of Pulicat, southeast coast of India. Indian Journal of Marine Science, 23: 39–42.