TheAcademy . 22/10/2024 5:30 PM
Why in News?
Recently, researchers studied the vertical migration of Pyrocystis noctiluca, a bioluminescent phytoplankton species capable of inflating its size during migration. This species can expand to six times its original size, which aids in buoyancy during its vertical movement in the ocean.
Vertical Migration: Plankton perform vertical migration, traveling between the cold, dark depths and the surface of the ocean in a continuous cycle. This mechanism in single-celled phytoplankton, especially those without swimming appendages, is not fully understood.
Density Dynamics: Phytoplankton are typically 5%-10% denser than seawater, making it challenging for them to stay near the surface for photosynthesis. However, Pyrocystis noctiluca can control its density, enabling it to reach the surface.
Ballooning Mechanism: Researchers used a "gravity machine" to simulate ocean depth and found that inflated phytoplankton cells become less dense than seawater, allowing them to float upwards.
Inflation During Cell Division: As part of the cell cycle, Pyrocystis noctiluca inflates during division, where its vacuole takes in freshwater, causing the new daughter cells to swell and float upwards. This process aligns with its pursuit of light and nutrients over a seven-day cycle.
Microscopic organisms essential to marine ecosystems, forming the foundation of the marine food web. They drift with tides and currents, unable to swim against them.
Types of Plankton:
Phytoplankton: Photosynthetic organisms like cyanobacteria, blue-green algae, and diatoms that convert sunlight into energy and produce oxygen.
Zooplankton: Animal-like organisms, including krill and sea snails, which feed on phytoplankton and are crucial to the food chain.
Size: Plankton vary from microscopic species to larger ones like jellyfish.
Role in the Marine Food Web: Phytoplankton support the entire marine ecosystem by feeding zooplankton, which are, in turn, consumed by larger marine animals like whales.
Migration Patterns: Zooplankton migrate vertically, descending during the day to avoid predators and rising at night to feed, making this the largest migration on Earth, observable from space.
Plankton are found in both saltwater and freshwater ecosystems. Clear waters usually indicate fewer plankton, while turbid waters are often rich in them.
