Common name: Smooth-breasted snakehead (Sri Lanka). Kolla (Leaf) or
Gas (Tree) kannaya (Sri Lanka)
First description: Bloch, M.E. & Schneider, J.G. 1801
Systema Ichthyologiae, Berlin ; p.496.
Meristic: D: 31-34 A: 20-22 P: 13-15 V: Absent Ratio: 2.8-3.5
Description: The colouration of the dorsal fin is a pale olive brown
displaying in the middle, a bluish green band. The outer margin is orange and
the tips of the rays, light in colour, body bands cross in the latter part.
The bluish-green anal has a dark olive or slate coloured longitudal band on
the external edge and is similarly crossed by body bands. The round caudal is
pale yellow, having seven dark transverse stripes (which can be sometimes
luminous blue). The orange pectorals have 4-7 transverse stripes.
Against the light cinnamon upper body background there are 10-13 dark bars
across the back. The mid-lower section is olive brown ventrally, the belly
and throat colouration being a bluish green. There are also dark W-shaped
transverse bands in the flanks.
The head has a dark lateral line from the snout, through the eye, to the
opercle. Several other lines cross the crown of the head. Occasionally a
series of minute black spots adorn the sides.
Myers & Shapovalov (1931),
in a significant taxonomical reclassification,
discussed in detail the differences between Ophicephalus and Channa and
rejected the former as a generic synoynm. This was based on a comparison
of O.gachua (with pelvic fins) and C.orientalis (without pelvic fins) by a
detailed analysis of the following points :-
(i) The genera Ophicephalus and Channa had been previously separated by the
single character of the phyloric or coecal appendages being present or absent.
(ii) Hora (1921)
and Deraniyagala (1929)
found that the phyloric caeca were
present in both O.gachua and C.orientalis.
(iii) Deraniyagala (1929)
states that the Sri Lankan species O.gachua (later
to become Channa gachua) and C.orientalis were identical in the important
character of head shield (scales) patterns on top of the head.
(iv) He (Deraniyagala 1929)
also gave a detailed description of the two
species and found no significant differences (apart from the lack of pelvic fins).
(v) The bold pectoral barring and overall colouration is similar.
(vi) O.gachua and C.orientalis can be found in the same biotope.
(vii) Quoting Day (1878-1888);
"It is not uncommon in India to find specimens of
Ophicephalus gachua having a ventral fin deficient, but I have not observed both wanting".
(viii) A specimen of O.gachua lacking both pelvic fins was taken on the
Island of Formosa by Leo Shapovalov.
The authors (Myers & Shapovalov 1931),
following the strict rules of Zoological
Nomenclature, (uniting the two genera and including the African species) boldly
affirmed that Ophicephalus be merged into the single genus Channa. Concluding
that C.orientalis may be regarded as a 'series of anomalous specimens' they
strangely, after an excellent discussion on the basis of the species merging,
were, however, hesitant to synonymise, (as was
Deraniyagala 1929), listing the
fish separately as C.orientalis and C.gachua.
However, differences between C.orientalis and C.gachua are the following :-
1) C.orientalis is endemic to Sri Lanka.
2) C.gachua attains a larger size than C.orientalis.
3) Generally C.orientalis does not posess ventral fins while C.gachua
generally has ventral fins.
4) The breeding behaviour of C.orientalis is to orally incubate their eggs
whilst C.gachua orally incubate, build a crude nest or scatter their eggs.
5) Generally C.orientalis is the more colourful species.
Juvenile differences in colouration: The young fish have a base colour
of pale reddish-yellow, covered by a meandering lateral streak of orange from
the snout to the caudal fin. There is a similar head band and the body bars are
most distinct at a size of 50 mm. Sometimes an ocellus (or several) can be seen
in the latter half of the dorsal fin amongst juveniles of a size 25-53 mm long
Size: The smallest of the genus, attaining a maximum length of 105 mm.
Synonyms: Deraniyagala (1929)
states, 'this fish (C.orientalis) is
almost identical to O.gachua (later to become C.gachua kelaarti) in colour',
but hesitates to synonmise the two fish.
In their excellent re-classification of Channidae,
Myers & Shapalov (1931)
draw attention to the great similarities of the two species and in particular
the relationship of the shape, colour and the absence or presence of ventral
fins. Concluding their discussion however, the fish were listed as distinct
species and in the case of C.orientalis, the genotype of Channa.
Geographical location: Both
Deraniyagala (1929) and
list this fish as endemic to Sri Lanka.
'Kolla kannaya' in its natural habitat can be found in clean, freshwater pools
close to streams. C.orientalis was found in Sri Lanka by Roth
(Bachmann and Vierke, 1986)
who recorded the water at 6.3 pH and a
temperature of 24 °C. It is best kept in an aquarium with filtered water,
as this species does not seem as hardy as the closely related C.gachua.
If several adult fish are to be kept, a large tank must be provided as
they are quarrelsome towards each other, causing bad injuries, even fatalities.
They can jump out from the water very well, so a tight-fitting lid is needed.
In the aquarium, they can be trained to take beast heart, worms and small fishes.
Breeding: Roth (1985)
conditioned his pair of C.orientalis firstly on
beast heart and then small live fish. Each day the the fish became more colourful.
A beautiful steel blue replaced the dirty yellow body. The margins in the fins
became more intense.
A large area of gravel was removed in the corner of the tank. After spawning,
the male's throat was distended and some 10 days later 80-100 fry approximately
3mm long emerged from the mouth. They browsed on the algae on the side of the
tank and in two weeks had doubled in size. The male still guarded the young at
an age of 8 weeks.
As illustrated, a further difference between this species and the closely
related, C.gachua is in breeding behaviour. C.orientalis orally incubates
it's eggs whilst some records suggest that the fry of C.gachua in India are
raised in a watery nest (
Mookerjee et al 1950.
stated that C.orientalis without pelvics carried eggs for
9-10 days and produced 40 fry while C.orientalis with pelvics carried the eggs
for 3-4 days and produced up to 200 fry. The eggs floated and were taken into
the mouth of the male. However, the female of the strain without pelvics
expelled sinking eggs which were eaten by the fry. Differences in the behaviour
of the fry were also noted. He may have been recording differences between
C.orientalis and C.gachua, of course and the difference in egg numbers may
have been due to the age and experience of the parents.