What are the differences between black carp and grass carp? A quick guide to telling the two fish apart

The main external difference between black carp and grass carp is body color. The back and fins of the black carp are distinctly blue-black, the head is relatively pointed, and the intestines are short, only slightly longer than its own body length. The grass carp is lighter in color than the black carp, appearing blue-yellow, with the pectoral and pelvic fins tinged with grayish yellow; the head is relatively blunt, and the intestines are long, about more than 2 times the body length.

Morphological characteristics of grass carp

The grass carp is the only species in the genus Ctenopharyngodon, subfamily Leuciscinae, family Cyprinidae, order Cypriniformes. Also known as the white amur, grass root fish, and thick fish. The body is slightly cylindrical, the head is somewhat flat and depressed, and the tail is laterally compressed. The mouth is arcuate, with no barbels. The upper jaw is slightly longer than the lower jaw. The body is light tea-yellow, the back is blue-gray, the belly is grayish white, the pectoral and pelvic fins are tinged with grayish yellow, and the other fins are light gray. The body is relatively long, with no ventral keel. The head is flat and depressed, and the tail is laterally compressed. The lower pharyngeal teeth are in two rows, laterally compressed, comb-shaped, with transverse grooves on the tooth sides. The dorsal fin and anal fin both lack hard spines, and the dorsal fin is opposite the pelvic fins.

External characteristics of black carp

The black carp has a long body, slightly cylindrical, with a flat and rounded belly and no ventral keel. The tail is slightly laterally compressed. The snout is blunt, but more pointed and protruding than that of the grass carp. The posterior end of the maxilla extends below the anterior margin of the eye. The interorbital space is about 3.5 times the eye diameter. There are 15 to 21 gill rakers, short and small, papilliform. The pharyngeal teeth are in one row, 4(5)/5(4), generally asymmetrical on the left and right, with broad, molar-like tooth surfaces. The scales are large and round. There are 39 to 45 scales in the lateral line. The body is blue-black, darker on the back; the fins are gray-black, especially the paired fins. The dorsal fin has 7 to 9 soft rays; the anal fin has 8 to 10 soft rays, and the body length can reach 145 cm.

Main differences between grass carp and black carp

1. Color distinction: the grass carp is light yellow, with clear scales; the black carp's body and fins are gray-black.

2. Head distinction: the grass carp has a rounded mouth, with obvious scales; the black carp's scales are not obvious, and its head is more pointed.

3. Size: generally speaking, within one growth cycle the black carp grows larger than the grass carp.

4. Price distinction: generally speaking, the black carp is somewhat more expensive than the grass carp.

5. Feeding habits: the grass carp generally lives in the middle layer of the water and mainly eats the stems and leaves of aquatic plants; the black carp lives in the lower layer of the water and mainly eats bottom-dwelling animals such as snails and mussels.