Common name: Dudu-cheng or Tel-cheng (Bengal); Sen-ga-lee (Assam)
First description: Playfair, R.L. 1867
On the fishes of Cachar.
Proceeding Zool. Soc. London. pp.14-15.
Diagnostic: The shape is similar to C.marulia (
Shaw & Shebbeare 1937).
Chatterjee and Dhar (1985)
compared C.stewarti using isozyme (protein) analysis to four other species, all
caught in the same area. These were C.barca, C.punctatus, C.orientalis and
C.striatus from the neighbourhood of Gauhati, (State of Assam) India. There are
distinct differences betweem C.stewarti, C.orientalis and the forementioned.
Further, there are also differences in the protein bands of the heart and liver.
Meristic: D: 39-40 A: 27 C: 14 V: present Ratio: 4.0
Description: The colouration of the dorsal fin is dark with a deep
blue iridescence along it's base. It is spotted white and has a white- orange
outer edge. The anal and caudal are similarly dark, but without markings. The
pectorals have zonal spots.
The upper body background colouration is dark brown, with about eight indistinct
darker bands sloping forwards towards the head, above the lateral line and a short
distance below it. Some scales have a well defined, circular black spot, concentrated
when they draw near to the bands. The mid and lower section is lighter but the
spotted scales are fewer and congregate towards the caudal peduncle.
On the head, under the chin, there is a 'marbled' pattern.
Juvenile differences in colouration: The lower half of the pectoral
fins in the young are yellow and display a blue basal spot and transverse darker
cross bands. The dorsal is edged with a lighter yellow. The original describer,
Lieut.-Colonel R.L.Playfair (1867),
also mentioned that in immature specimens of
100 mm, the distinguishing spots on the scales cannot be seen.
Size: 450 mm (
Shaw & Shebbeare 1937)
Sub-species and colour variants:
C.stewarti Assam form<br>
The ground colour is purplish black , it is a lighter grey/white further down,
whilst the dorsal fin is edged yellow.
Synonyms: Ophicephalus stewarti
Playfair (1867) found this fish first in the
most easterly, old-named, province of Cachar, India.
Shaw & Shebbeare 1937(1937)
report that its habitat is the clear streams in the forests of the 'Duars'.
Sen (1985) names the Eastern Himalayas, Arunachal Pradesh, Meghalaya,
West Bengal, Nepal and the Andaman Islands.
It is also reported that C.stewarti can be found in marshy bodies of water and
estuarine conditions, where they can withstand a brackish water environment.
Such specimens were caught by
at Diglipore, North Andaman Islands,
from a wide freshwater canal with connections with the sea.