Slender glass flea
Diaphanosoma brachyurum
The slender glass flea is a small, nearly completely transparent crustacean from the order Cladocera. It is characterized by the absence of a rostrum and long, biramous swimming antennae that almost reach the length of its body. It primarily inhabits the pelagic zone of standing waters and is a typical representative of summer plankton, as it prefers higher water temperatures.
Details
Identification
No rostrum on the head, head clearly separated from the trunk, swimming antennae with two branches (one 2-segmented, one 3-segmented), body highly transparent.
Social behavior
Often occurs in high individual densities in the pelagic zone, but does not form complex social structures.
Diet
Actively filters bacteria, detritus, and small phytoplankton (nannoplankton) from the open water.
Spawning substrate
Eggs are carried in a brood chamber on the back; resting eggs sink to the bottom of the water body.
Overwintering
Overwintering occurs as resting eggs (ephippia) in the sediment, while adult populations usually collapse during winter.
Ecology
Ecological role
Important primary consumer that transfers energy from phytoplankton to higher trophic levels (fish).
Natural predators
Planktivorous fish (e.g., bleak), predatory zooplankton like Leptodora kindtii, and aquatic insect larvae.
Competitor species
Other cladoceran species such as Daphnia longispina or Bosmina species.
Ecosystem service
Contributes to the regulation of algal biomass and the self-purification of water bodies.
Threats
Heavy eutrophication, acidification of water bodies, and climate change (alteration of stratification dynamics).
Scientific profile
Profile
Distinguishing features
Long swimming antennae that, when reflexed, almost reach the posterior margin of the valves; antennal endopod is 2-segmented, exopod is 3-segmented; posterior margin of the valves features a row of fine spines; postabdomen lacks anal spines but possesses groups of fine setae.
Reproduction
Cyclical parthenogenesis; rapid asexual reproduction occurs during favorable summer months, while males and resting eggs are produced when conditions deteriorate (autumn).
Role in food web
Important link in the pelagic food web, transferring energy from the microbial loop (bacteria) to higher trophic levels (fish).
Protection & threats
Status not on standard scale
Main threats
Acidification of water bodies (sensitive to low pH), extreme eutrophication with cyanobacterial blooms (clogging of the filtering apparatus), and invasive predators.