Pseudo-nitzschia is a genus of diatoms, which are microscopic algae found in marine and freshwater environments. These organisms are important components of the aquatic food web and contribute to primary production. They have unique silica cell walls that can form intricate patterns, making them visually distinctive under a microscope. Some species of Pseudo-nitzschia are known to produce harmful toxins, particularly domoic acid, which can accumulate in shellfish and pose risks to human health. Monitoring these species is crucial for ensuring seafood safety and protecting marine ecosystems from potential outbreaks of harmful algal blooms.