Loricate euglenid
Trachelomonas
Trachelomonas is a genus of single-celled flagellates characterized by a rigid, often brown or reddish protective shell called a lorica. This shell is frequently impregnated with mineral deposits such as iron or manganese and features a small pore through which a single flagellum emerges. The cells contain chloroplasts for photosynthesis and a prominent red eyespot for phototaxis. They are primarily found in stagnant, nutrient-rich freshwater environments.
Details
Oxygen production
Produces oxygen as a byproduct of photosynthesis in the epilimnion.
Habitat function
Serves as the basis of the food chain in small standing water bodies.
Nutrient uptake
Absorbs inorganic salts as well as iron and manganese compounds for lorica formation.
Food source for
Small zooplankton and filter-feeding macroinvertebrates.
Human use
Used in limnology as an indicator organism for water quality.
Ecology
Ecological role
Primary producer in the aquatic food web; important for the iron cycle in water bodies.
Natural predators
Zooplankton such as rotifers and small crustaceans (Cladocera).
Competitor species
Other phytoplankton species such as Euglena or green algae.
Ecosystem service
Oxygen production through photosynthesis and nutrient sequestration.
Threats
Extreme herbicide contamination and massive habitat changes.
Scientific profile
Profile
Distinguishing features
The primary feature is the lorica with an apical opening (pore), often surrounded by a collar, through which the flagellum emerges. The envelope is frequently colored yellowish, brown, or deep red due to the impregnation of iron and manganese compounds. Inside is a typical euglenoid cell with numerous disc-shaped chloroplasts.
Reproduction
Asexual reproduction by longitudinal binary fission within the lorica. One of the daughter cells exits the old envelope through the pore, swims freely, and subsequently secretes a new lorica from mucilage and mineral deposits.
Protection & threats
Status not on standard scale
Main threats
Loss of small water bodies due to infilling or drainage; excessive herbicide input from agriculture.
Conservation measures
Protection and creation of ponds and pools; reduction of nutrient and pollutant inputs from adjacent agricultural land.