The Greek word myxa means slime. They are known as hagfish. The ugly fish is called slime eel. Their number of species is 70.
1. Their bodies are slender, elongated, with slippery glands and without paired fins.
2. They look like eel or bine fish.
3. The spinal cord consists of notochord and fibrous neural tube.
4. Their mouth is marginal and has 4 pairs of gills.
5. They have 5–15 pairs of florets.
6. Their nasal sacs open into the oral cavity.
7. The forebrain forms the brain. Cerebellum absent. There are 10 pairs of carotid nerves.
8. They are known as hagfish.
9. They feed on annelids, molluscs, crustaceans, arthropods or dead fish.
10. The digestive system does not contain a stomach and the intestinal spiral is absent.
11. They are all marine.
12. Their life cycle does not have a larval stage.
13. They are unisexual animals. They are excreted. Eggs are yolky and large.
[KEY WORDS TO REMEMBER CHARACTERISTICS: bine, mouth margin, larynx, larynx, nasal sac, hagfish]