Common Needle Diatom
Fragilaria ulna
The common needle diatom is a widespread diatom characterized by its extremely long, rod-shaped cells. It often forms fan-shaped colonies on solid substrates or aquatic plants, but also occurs in the open water. Its cell wall consists of two siliceous valve halves with characteristic fine transverse striae and a hyaline central area.
Details
Oxygen production
Produces significant amounts of oxygen during the light phase.
Habitat function
Serves as a periphyton habitat for microorganisms and as a food source for grazers.
Nutrient uptake
Absorbs dissolved silica for skeleton construction as well as nitrate and phosphate.
Food source for
Snails, insect larvae, small crustaceans, and various fish larvae.
Human use
Used in paleolimnology to reconstruct past environmental conditions.
Ecology
Ecological role
Important primary producer; forms the base of the food chain in benthic and planktonic habitats.
Natural predators
Zooplankton (e.g., Daphnia), benthic invertebrates (e.g., mayfly larvae), and herbivorous fish.
Competitor species
Other diatom species as well as green algae and cyanobacteria competing for light and nutrients.
Ecosystem service
Oxygen production through photosynthesis and contribution to carbon sequestration.
Threats
Heavy chemical pollution, herbicide input, and extreme acidification of water bodies.
Scientific profile
Protection & threats
Main threats
Deterioration of water quality due to toxic pollutants (e.g., herbicides), extreme hydromorphological changes, and massive acidification of water bodies.