1. Ichthyophis is a burrowing, elongated and eel-like animal and measures up to 30 cm in length. Body is divided into head, trunk and tail.
2.The colour of the body is dark brown or bluish-black with a yellow band along the side.
3. Skin is provided with numerous transverse grooves or wrinkles in which minute scales are embedded. Squirt glands present in the skin discharge an irritating fluid.
4. Limbs and limb-girdles are entirely absent.
5. Tail is short or vestigial.
6. Eyes are minute, devoid of lids buried deep in the head, are non-functional. A protrusible tentacle (sensory organ) present between the nostril and the eye.
7. Tympanic membrane and columella are absent.
8. Vertebrae amphicoelous.
9. Laryngotracheal chamber is prolonged into a distinct trachea. Right lung elongated and left lung is reduced.
10. Sexes separate, males possess large eversible copulatory organs provided with hooks.
Fertilization internal. Eggs are meroblastic.
11. Parental care is very well developed. Female coils herself around the gelatinous egg mass to protect it from ground burrowing animals.
12. Larva possesses three pairs of very long finely branched external gills.
Source:
1. Practical Zoology Vertebrates by S.S.Lal. 2. A Manual of Practical Zoology Chordates by Dr. P.S. Verma.
