Context;
Comb jellies, also known as ctenophore Mnemiopsis leidyi, can defy age and revert to younger versions of themselves, according to a study published recently.
Relevance:
Facts for Prelims
Comb Jellies
Comb jellies, members of the phylum Ctenophora, are transparent, gelatinous invertebrates that drift through global ocean waters. These creatures are one of the oldest multicellular phyla in the animal kingdom, with an existence that likely spans over 500 million years. There are between 100 and 150 known species of comb jellies, many of which are commonly found close to shorelines.
Description and Characteristics
Physical Appearance:
- Comb jellies are typically colorful and simple in structure. The average comb jelly is about four inches long, though sizes can vary among different species.
- Their most distinctive feature is the eight rows of fused cilia—tiny hair-like structures—resembling combs, which they use for locomotion. They are the largest known animals to use cilia as a means of movement.
- They possess two large, trailing tentacles that branch out, creating a net-like appearance and functioning as sticky fishing lines to capture and transport prey to their bodies.
Biological Features:
- Comb jellies have two primary cell layers: an external epidermis and an internal gastrodermis, with a gelatinous mesoderm sandwiched between these layers, contributing to their jelly-like consistency.
- Many species exhibit bioluminescence, capable of emitting a captivating blue or green glow in response to physical stimuli, such as touch.
Feeding Habits:
- These organisms are carnivorous and opportunistic feeders, consuming a variety of prey that comes into contact with their tentacles.
- Unlike jellyfish, their close relatives, comb jellies do not possess stinging tentacles, making them harmless to humans.
Ecological Role
Comb jellies play a significant role in marine ecosystems, primarily as predators of small aquatic organisms. Their presence helps regulate the populations of various marine species, contributing to the ecological balance within their habitats. Despite their ancient lineage and simplicity, comb jellies continue to thrive in diverse marine environments around the world.
-Source: Indian Express
