Morphology of Indian populations of Coleps elongatus (Ehrenberg, 1830) Kahl, 1930 and C. amphacanthus Ehrenberg, 1833 (Ciliophora: Prostomatea: Prorodontida)
Author
Ghosh, Subhadeep
Author
Bharti, Daizy
Author
Kumar, Santosh
text
Records of the Zoological Survey of India
2021
121
4
447
452
journal article
10.26515/rzsi/v121/i4/2021/158008
2581-8686
13184752
1.
Coleps elongatus
(Ehrenberg, 1830)
Kahl, 1930
(
Figure 1A–O
;
Table 1
).
Two populations were studied, one from the protected area (Mahananda Wildlife Sanctuary) of
West Bengal
and another from the small natural freshwater pond (Senhati Jheel) in Kolkata.
Description:
(
Mahananda Wildlife Sanctuary population
) (
Figure 1A–H
): Size in vivo 30-50 µm × 15-25 µm on average, usually about 45 µm × 25 µm, as calculated from some in vivo measurements (n=4) and the morphometric data in
Table 1
, adding 15% for preparation shrinkage (
Kumar and Foissner 2016
; Kumar
et al
., 2016). Body slender with length: width ratio about
2.0. Macronucleus, spherical, 7.0–10.0 µm across, below midline towards posterior body end. Cortex without symbiotic algae. Contractile vacuole at posterior end of the body. Armour brownish, anterior end narrow with single spine, posterior end rounded with three distinct caudal spines.
Six types
of armour tiers with 13 windows: anterior secondary with 2, anterior main with 5, posterior main with 4, and posterior secondary with 2 windows. Windows pretzel-shaped or
hirtus-
type
. Body midline strongly distinguished by the borders of anterior and posterior main plates. Thirteen transverse ciliary rows and about 15 meridionally arranged somatic kineties. On average, two distinct long caudal cilia.
Figure 1.
Photomicrography of
Coleps elongatus
Mahananda Wildlife Sanctuary
population from live
(
A-E) and after protargol impregnation (F-H), Senhati Jheel population from live (I-L) and after protargol impregnation (M-O).
A.
Specimen showing typical barrel shaped body.
B.
Arrows showing anteriormost plates.
C.
Arrow indicating globular macronucleus.
D.
Arrowhead indicating contractile vacuole at the posterior body end.
E.
Arrow showing two distinct caudal cilia.
F, G.
Specimen showing ciliature on the dorsal and ventral surface.
H.
Oral ciliature.
I.
Specimen showing body shape, arrow indicates anterior spine and arrowheads point caudal spines.
J.
Specimen showing armour plate and 3
rd
caudal spine in different focus.
K.
hirtus-
type of armour.
L.
pretzel-shaped window.
M.
Specimen showing dorsal ciliature.
N.
Macronucleus.
O.
Oral ciliature with perioral kineties. Scale bars: A, F, G, M- 15 µm; I, J- 20 µm; N- 10 µm.
Table 1.
Morphometric data on
Coleps elongatus
(Ehrenberg, 1830)
Kahl, 1930
(Mahananda WLS population-M, Senhati Jheel population-Sj)
|
Characteristic
a
|
Pop
|
Mean
|
M
|
SD
|
SE
|
CV
|
Min
|
Max
|
n
|
| Body, length |
M |
34.0 |
35.0 |
3.4 |
0.9 |
10.0 |
28.0 |
42.0 |
14 |
| Sj |
40.7 |
40.0 |
3.5 |
1.0 |
8.7 |
36.0 |
50.0 |
13 |
| Body, width |
M |
18.3 |
18.0 |
3.0 |
0.8 |
16.2 |
15.0 |
26.0 |
15 |
| Sj |
21.6 |
20.0 |
4.1 |
1.1 |
18.7 |
17.0 |
0.0 |
13 |
| Body length:width, ratio |
M |
1.8 |
1.9 |
0.2 |
0.1 |
12.7 |
1.3 |
2.2 |
14 |
| Sj |
1.9 |
2.0 |
0.3 |
0.1 |
14.4 |
1.3 |
2.4 |
13 |
| Anterior body end, width |
M |
8.4 |
8.0 |
1.1 |
0.3 |
12.8 |
7.0 |
10.0 |
10 |
| Sj |
8.9 |
9.0 |
1.1 |
0.3 |
12.2 |
7.0 |
10.0 |
12 |
| Macronuclear nodules, number |
M |
1.0 |
1.0 |
0.0 |
0.0 |
0.0 |
1.0 |
1.0 |
16 |
| Sj |
1.0 |
1.0 |
0.0 |
0.0 |
0.0 |
1.0 |
1.0 |
10 |
| Macronucleus, diameter |
M |
8.7 |
9.0 |
0.9 |
0.2 |
10.4 |
7.0 |
10.0 |
15 |
| Sj |
7.8 |
7.5 |
1.5 |
0.6 |
18.8 |
6.0 |
10.0 |
6 |
| Cirral rows, number |
M |
13.0 |
13.0 |
0.0 |
0.0 |
0.0 |
13.0 |
13.0 |
16 |
| Sj |
13.0 |
13.0 |
0.0 |
0.0 |
0.0 |
13.0 |
13.0 |
8 |
| Caudal cilia, number |
M |
2.0 |
2.0 |
0.0 |
0.0 |
0.0 |
2.0 |
2.0 |
10 |
| Sj |
2.0 |
2.0 |
0.0 |
0.0 |
0.0 |
2.0 |
2.0 |
10 |
aData
based on mounted, protargol-impregnated, and randomly selected specimens from a clonal culture. Measurements in µm. CV
– coefficient of variation in %, M – median, Max – maximum, Mean – arithmetic mean, Min – minimum, n – number of individuals investigated, SD – standard deviation, SE – standard error of arithmetic mean.
The Senhati Jheel population (
Figure 1I–O
) is slightly larger (40.7 µm vs. 34 µm) then the Mahananda Wildlife Sanctuary population. Other characters were rather similar (for details refer
Table 1
).
Coleps elongatus
has been mentioned in two articles published from
India
however, their identification is doubtful.
Material deposited
: A slide including protargolimpregnated specimens have been deposited at the National Zoological Collections of the Zoological Survey of
India
, Kolkata,
India
with the accession numbers Pt 4276 (MWLS population) and Pt 5200 (Senhati Jheel population).
Occurrence and ecology
: Cosmopolitan distribution, feeds on bacteria and flagellates.