i) Catla catla (Nga-thaing-gaung-bwa)
The head is broad and moderately large; no barbels present; the mouth is anterior, lips slightly thick but not fringed. In fry stage (12 – 35 mm size) the opercular region has a bright reddish tinge due to the red gills seen through the transparent opercular flaps. The dorsal profile of the anterior portion of body is convex and the ventral profile is concave. The first ray and the dorsal edge of the dorsal fin have a blackish tinge. There is a definite circular black spot present at the caudal peduncle which persists until the fry grows to about 150 – 160 mm in size. In the Indian strain of catla, no such black spot is present. The colour of the fins is either grey or blackish.
ii) Labeo rohita (Nga-myit-chin)
Rohu fry has a stream-lined body, lips are fringed, one pair of barbels (maxillary) is prominent even from 15–20 mm size and is whitish-grey in colour. The caudal peduncle has a dark spot which connects both the edges giving the appearance of a band. In some fry the spot is more circular. The dorsal surface or the back of the fingerlings is slightly greenish. The ventral and anal fins have a reddish tinge and both the lobes of the caudal fin have a reddish tinge with blackish grey marginal areas.
iii) Labeo calbasu (Nga-net-pya)
It is easier to identify the fry and fingerlings of L. calbasu. At the very early stage of 7–9 mm size the fry develops an alternate white and dark band on the back. The fins become black at the base and usually the black colour spreads all over as the fry grows. A semi-lunar yellow band appears at the nape and the fry at 15 – 25 mm size can easily be identified by the alternate yellow and black band along the body. The barbels, maxillary and rostral, appear at an early stage and are prominent and black in colour. The mouth is narrow and the lips are fringed. As the fry grows, the body and fins become blacker and finally at the fingerling stage L. calbasu becomes completely blackish-grey.
iv) Labeo gonius (Nga-dane)
The fry of L. gonius has a smaller head, narrow mouth, lips are fringed and possesses one pair of maxillary barbels. The rostral barbels appear only in the fingerling stage. An indistinct spot is present at the caudal peduncle. The body has a number of faint white stripes which become more prominent in fingerlings when the black spots in the scales give rise to alternate dark and white longitudinal stripes along the body. The scales are very small. The colour is light green at the back and dull white ventrally.
v) Labeo nandina (Nga-ohn-done)
Labeo nandina fry has a small ventrally placed narrow mouth with fringed lips and two pairs of prominent barbels which are grey in colour. Like L. gonius, the fry develops dark longitudinal stripes. It can be easily distinguished from other Labeos by the elongated dorsal fin. The fry possesses one dark oval spot at the caudal peduncle which becomes fainter in fingerlings. The fringed lower lip, however, develops prominent villi-like protuberances at the fingerling stage.
vi) Labeo stoliczkae (Nga-thaing)
The fry of L. stoliczkae has a larger head as compared to other Labeo species. There are barbels, the mouth is wide and the lips are very slightly fringed. The caudal peduncle has a dark spot which becomes very faint in the fingerlings. The most important distinguishing characteristic of L. stoliczkae is the prominant black band in the body bordering the posterior edge of the operculum. This characteristic persists even in the adult fish.
vii) Labeo pangusia (Nga-loo-me-netha)
The fry and fingerlings of the minor carp L. pangusia resemble those of L. rohita very much. The fry has a narrow, crescentic mouth with fringed lips and possesses a pair of barbels. The spot at the caudal peduncle also resembles rohu to a certain extent but it persists even in the adult though somewhat indistinct. The colour of the back of the body is not so greenish as in rohu. The main point of distinction between this minor carp and rohu is that the mouth of the former is more ventral, hanging and more crescentic than the latter. Besides, the isthmus of L. pangusia meets the lower lip converging to a point and forms a depression on both sides at that point. In the case of L. rohita advanced fry and fingerlings, the isthmus instead of converging meets the lower lip at a broad base and no cavities are formed on both sides.
viii) Labeo angra (Nga-loo)
The fry of L. angra is pale yellowish in body colour. The mouth is ventral, narrow and the lips are fringed. A pair of barbels are present and the fry is pale whitish in colour. A conspicuous dark band is present at the nape. At the caudal peduncle there is a distinct oval shaped spot. Two other spots are present at the body below the dorsal and anal fins. The caudal spot persists even in the adult. In Indian specimens, L. angra fingerlings develop a conspicuous lateral band which is very indistinct in the Burmese specimen. The band also does not persist in the adult in the Burmese specimen as is observed in Indian specimens.
The fry of L. angra resembles to a certain extent the fry of L. calbasu. The main points of difference between the two are that the former has a yellowish body colour, a conspicuous dark caudal spot and dark pigment is absent in fins. The barbels are dull white in colour in contrast to the black barbels of L. calbasu. The dark band at the nape is common for both the species but in L. calbasu the band lies in between two yellow bands.
ix) Labeo boga (Kyouk-nga-loo)
The fry of L. boga has a terminal mouth and unlike other Labeo spp. the thin lips are without any fringes. A black spot is present at the caudal peduncle near the base of the caudal fin, which becomes more conspicuous as the fry grows to fingerling stage. The spot is triangular in shape with its broad base parallel to the base of the caudal fin. It becomes more or less circular in the fingerlings. At 25–30 mm size a pair of barbels is visible. The fry at this stage also develops a spot on either side of the body on the 5th and 6th scales in one or two rows above the lateral line. The spots continue up to 175–180 mm size. At this size the caudal spot disappears. L. bata fry and fingerling have similar characteristics.
x) Cirrhina mrigala (Nga-gyin)
The fry of mrigal has a slender elongated body. The head is narrow and the mouth is wide and terminal. The lips are thin without any fringes. A black spot appears on the caudal peduncle at a very early stage. The spot finally takes the shape of a diamond at the 30–35 mm stage. At this stage a pair of grey barbels is also visible. The fingerlings can more easily be identified by the reddish tinge at the tip of the lower lobe of caudal fin.
Mrigal fry can be distinguished easily from rohu and other major carps but it is rather difficult to distinguish it from those of Labeo boga or L. bata. The shape of the caudal spot is the most important character by which the two species could be identified. With the appearance of a spot on the lateral line in L. boga, and a reddish tinge at the tip of the lower lobe of caudal fin in mrigal they can be easily identified.
xi) Osteochilus chalybeatus (Nga-leh)
The early fry of O. chalybeatus could not be studied as specimens were not available. The fingerlings more or less resemble L. calbasu because of their uniform dark grey or blackish body and fin colour. Lips are fringed like most of the Labeo species. Two pairs of barbels are present which are dark grey in colour. The fingerlings can be distinguished from L. calbasu by the elongated dorsal fin.
xii) Barbus sarana (Nga-khon-ma)
The fry of B. sarana is characterized by the presence of a black vertical band originating from the base of the anterior position of the dorsal fin and extending to near the lateral line. It has also a conspicuous oval spot on the caudal peduncle. The body is deep and compressed. The mouth is anteriorly placed and the lips are thin and without fringes. Prominent maxillary barbels are present. A pair of rostral barbels also appears at about 25 mm stage.
xiii) Osteobrama belangeri (Nga-hpe-oung)
The fry of O. belangeri has a narrow pointed head and a wide and compressed body. The abdomen is trenchent throughout. No barbels are present. There is a conspicuous rectangular spot at the caudal peduncle which disappears in the adult. The spot sometimes extends up to the edges of the caudal peduncle and appears like a band.
In the foregoing a few important characteristics of common fry and fingerlings of Burmese carps have been mentioned. No attempt has been made to describe the salient features of the fry and fingerling at various stages in detail. These are only a few characteristics by means of which each species can be identified in the field so that the economic varieties can be distinguished from the non-economic ones. In doubtful cases, if there is difficulty in distinguishing between L. rohita and L. pangusia or between C. mrigala and L. boga, it is advisable to count the number of divided dorsal fin rays. In minor carps the number of divided fin rays in dorsal fins are either eleven or less whereas in major and medium sized carps the number is always more than eleven.