Classification:

• Phylum : Arthropoda
• Class : Crustacea
• Order : Rhizocephala
• Genus : Sacculina

Comments:

1. 1. Sacculina is commonly known as root-headed barnacle.
2. 2. It has the appearance of a fleshy tumor attached by a peduncle to the abdomen of the crab on its ventral side.
3. 3. It shows extreme degeneration due to parasitic mode of life.
4. 4. Segmentation, appendages, mouth and anus are entirely absent.
5. 5. Peduncle sends numerous delicate root-like filaments which ramify within the body of the host and absorb nourishment.
6. 6. Opening of the mantle cavity of sacculina is placed at the hind end of the parasite as genital aperture or cloacal aperture.
7. 7. Hermaphrodite, i.e., sexes are united.
8. 8. Larva is cirripede-nauplii.

Source:

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