Diagnostic Characteristics at Different Life History Stages of Indian Major Carps

 

Species	Hatching
Catla	Av. Size 4.68 mm. bulbous part of yolk and narrow part of equal length. 26 pre-anal and 14 post-anal myotomes in most of the hatching.
Rohu	Av. Size 3.78 mm. Bulbous part of yolk and narrow part of equal length. 26 pre- anal and 14 post-anal myotomes in most of the hatching.
Mrigal	Av. Size 4.2mm. Narrow portion of the yolk greater in length than the bulbous part. Yolk more or less club shaped. 28 pre-anal and 14 post-anal myotomes in most of the hatchlings.
Species	24hr after hatching
Catla	Av. Size 5.49mm. narrow end and yolk does not end in a point sharply
Rohu	Av. size is 5.49mm. Narrow end of yolk somewhat sharply ending in a point.
Mrigal	Av. Size 6.21mm. narrow end and yolk does not end in a point sharply.
Species	36hr after hatching
Catla	Av size 6.40mm. anterior profile of yolk convex
Rohu	Av size 5.85mm. anterior profile of yolk convex
Mrigal	Av size 6.70mm. anterior profile of yolk sac more or less straight
Species	48hr after hatching
Catla	Av size 6.48mm.  Anterior profile of yolk convex
Rohu	Av size 6.20mm. Anterior profile of yolk convex
Mrigal	Av size 6.84mm. Anterior profile of yolk sac more or less straight.
Species	72hr after hatching
Catla	Av size 7.3mm. Reddish glow perceptible in the opercular area. Dark somewhat triangular spot in caudal peduncle.
Rohu	Av size 6.95mm. A few faint black pigment spots below notochord in caudal region. No reddish glow on the opercular margin.
Mrigal	Av size 7.20mm. Few black chromatophores in the caudal region. No reddish hue in the opercular area.
Species	4th day after hatching
Catla	Av size 7.56mm. Semicircular mark formed on black chromatophores, seen on ventral side of caudal towards end of notochord. The arc of the semi-circle not well defined and straight line of the semicircle is mildly concave. Lip margin thick. Reddish hue in abdominal area above anus. Dorsal fin separating from the embryonic fold.
Rohu	Av size 7.57mm. Crescent shaped semicircular area below notochord formed of black chromatophores in rows. Little above anus at the commencement of vertical fin fold, in majority of specimens there is a red steak visible even with unaided eye. Lip margins gently fimbriated.
Mrigal	Av size 7.38mm. Black chromatophores on dorsal fin rudiment, towards anterior portion. Black chromatophores below the tip of the notochord, confined to a semicircular area. Red colouration seen in abdominal region in rohu and catla absent. Lips thin. Dorsal fin separated from the embryonic fold.
Species	5th day after hatching
Catla	Av size 9mm. rays about 18 clearly visible below notochord, branching distally. 6 rays in the anterior port of the dorsal fin separating from embryonic fold.
Rohu	Av size 8.50 mm. caudal rays about 8-10 branching. Distinct red colouration in the abdominal region, in majority of specimens. Dorsal fin seen now, separating from the embryonic fold.
Mrigal	Av size 9.0 mm. caudal rays about 7, not branching. No rays in anterior part of dorsal fin which is separating from the embryonic fold.
Species	6th day after hatching
Catla	Av size 11 mm. body pale yellow. Chromatophore areas in the form of two crescent shaped areas in the caudal region. Anal fin bud absent.
Rohu	Av size 10.5mm. Dorsal side of the body yellow. Chromatophores from two crescents on two lobes of the caudal fin separated by a small colourless area. Anal fin bud present.
Mrigal	Av size 11.5mm. Dorsal half of body yellowish green. Two faint somewhat crescentic making on caudal peduncle. Anal fin bud present.
Species	7th day after hatching
Catla	Av size 12mm. 2 faint crescent shaped black chromatophore area just origin of the caudal rays on the caudal peduncle. Caudal not as deeply forked as in catla. Dorsal fin fully separated from embryonic fold. Membranous part of caudal fin anterior to the beginning of caudal rays sprinkled prominently with yellow pigment.
Rohu	Av size 11mm. 2 black chromatophore clusters at the caudal peduncle and two crescent shaped patches on caudal fin. Caudal less deeply forked than catla. Dorsal fin fully separated from embryonic fold. A few orange pigment dots in membranous part of caudal fin anterior to the beginning of caudal rays.
Mrigal	Av size 13.2mm. Black chromatophores form a triangle anterior to the origin of caudal rays on the caudal peduncle. Caudal not deeply forked as in catla dorsal fin fully separated from embryonic fold. Membranous part of caudal anterior to the beginning of caudal rays sprinkled prominently with yellow pigment.
Species	10th day after hatching
Catla	Av size 16.5mm. Lips thick. Mouth somewhat upturned. Dorsal fin margin appears dark due to chromatophores. Two distinct chromatophore patches on caudal peduncle slightly anterior to the origin of fin rays. Black chromatophores enclose a triangular area below the notochord far less distinct than in mrigal.
Rohu	Av. Size is 15.5mm. Thick fimbriated upper lip overhanging lower. No pigmentation on dorsal fin margin. Two faint black chromatophore concentrations on caudal rays, black chromatophores form a more or less broad based triangular area below the sharp bend of the notochord, each chromatophore being distinct.
Mrigal	Av. Size 15.6mm. Lips thin and adult like. Black chromatophores absent in dorsal fin margin. A triangular area packed with black chromatophores seen just anterior to the region of the beginning of the caudal rays, the black chromatophores fusing into one an another
Species	15th day after hatching
Catla	Av. Size 23mm. margin of dorsal fin drk. Faint yellow pigments covers dorsal fin rays up to 2/3 from base. Black chromatophores form a triangular area on caudal peduncle, the base appearing somewhat diffused. Scales not observed.
Rohu	Av. Size 23mm. thick fringed lips. Two barbels. Basal 2/3 of dorsal fin orange pigmented. Black chromatophore band in caudal region has a posterior prolongation from the centre passing through the origin of caudal rays and dividing the fin into two. Scales not observed.
Mrigal	Av. Size 27mm.  Body more pigmented compared to rohu and catla, particularly the dorsal half above the lateral line. This gives the appearance of faint parallel dark lines of a yellow background. Black pigmentation in caudal region more intense than in rohu and catla. No crescent shaped pigmented areas in the caudal region. Scales screen.