Classification:

• Phylum : Arthropoda
• Class : Crustacea
• Order : Thoracica
• Genus : Balanus

Comments:

1. 1. Balanus is commonly known as rock barnacle or acorn barnacle.
2. 2. Peduncle is absent so the shell is directly attached to the substratum or rocks.
3. 3. Body is surrounded by a calcareous shell consisting of six plates, an unpaired carina, an unpaired rostrum and two pairs of carino-lateral plates.
4. 4. The opening of the shell is provided with a four-fold cover consisting of two scuta and two turga.
5. 5. Six pairs of thoracic legs protrude out through the opening of the shell and sweep in food particles.
6. 6. Hermaphrodite, i.e.,sexes are united.
7. 7. Larva is nauplius.

Source:

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