The manubrium in a jellyfish is a stalk-like structure hanging down from the center of the bell (the umbrella-shaped body). It's centrally located on the underside of the bell and has the mouth at its tip. This mouth also functions as the anus.
The Manubrium's Role
The manubrium plays a crucial role in the jellyfish's biology:
- Feeding: The mouth at the end of the manubrium takes in food.
- Waste elimination: The same opening serves as the anus, expelling waste.
- Regeneration: The manubrium is involved in the jellyfish's remarkable regenerative capabilities. Studies show manubrium regeneration requires cell proliferation, and its morphogenesis is impacted by connections with the gastrovascular canal system. Removal of the manubrium affects the overall planarity of the jellyfish.
Examples of Jellyfish with Manubria
Many jellyfish species possess a manubrium. Examples include:
- Compass jellyfish: This species, known for its stinging capabilities, has a clearly visible manubrium.
- Lion's mane jellyfish: This large jellyfish, with its characteristic long tentacles, also features a manubrium.
- Freshwater jellyfish: Even freshwater jellyfish, unlike their marine counterparts, exhibit this characteristic structure.
The manubrium's central location and functions make it an important anatomical feature of jellyfish, highlighting their relatively simple, yet effective, body plan.
