Filamentous Algae
Pithophora spp.

Family:Green Algae (Pithophoraceae)
AKA: Pond Scum, Water Net
Photo taken on: September 28, 2021
Location: Roaring Judy Fish Hatchery, GV, CO
Life Zones: Plains to montane
Habitat: Shallow lakes and ponds

Filamentous algae form long chains of cells that look like threads or filaments. These filaments entwine and can form dense mats that are free-floating or attached to rocks, debris or other plants and look like wet wool, cotton, or slime. Three common types of filamentous algae are spirogyra, cladophora, and pithophora. Spirogyra is bright green and slimy. Cladophora has a cottony appearance and can form floating balls. Pithophora develops into lengthy strands that are dense. It is commonly referred to as horse hair algae because of this and has a texture like steel wool. The cause of these algal accumulations is an overabundance of nutrients, particularly phosphorus and nitrogen, in the water.