Classification:

• Phylum : Chordata
• Class : Osteichthyes
• Order : Acipenseriformes
• Genus : Acipenser

Comments:

1. 1. Acipenser is commonly known as sturgeon.
2. 2. Body is elongated about 2-4 meters in length and covered with five rows of bony scutes, one dorsal, two laterals and two ventrals.
3. 3. Head is produced ahead as a rostrum with a transverse row of four preoral barbels used for searching food.
4. 4. The mouth is small, ventral and protrusible. Jaws without teeth.
5. 5. Presence of functional open spiracles.
6. 6. Operculum is represented by an opercular bone.
7. 7. The air-bladder is smooth, oval and non-sacculated having a lining of ciliated epithelium.
8. 8. Skeleton cartilaginous.
9. 9. Dorsal fin single and posteriorly located. Anal fin opposite to dorsal fin and caudal fin bilobed (heterocercal). Paired fins are also present.
10. 10. A single fish lays 2-3 million eggs in a breeding season. European sturgeon?s eggs are black and are used to prepare a delicacy called Caviar.

Source:

1. Practical Zoology Vertebrates by S.S.Lal. 2. A Manual of Practical Zoology Chordates by Dr. P.S. Verma.