Glassy water flea
Leptodora kindtii
Leptodora kindtii is the largest native water flea and inhabits the pelagic zone of large, fish-rich lakes. Its body is almost entirely transparent, making it nearly invisible to predators in open water. It is a predator that feeds on other zooplankton, capturing them with a specialized feeding basket formed by its limbs.
Details
Identification
Total transparency (except for the black compound eye), long rod-shaped body, six pairs of predatory legs, biramous swimming antennae.
Social behavior
Lives solitarily in the pelagic zone but can occur in high densities under favorable conditions.
Diet
Predatory; feeds on smaller zooplankton such as Daphnia, Bosmina, copepods, and rotifers.
Hunting strategy
Ambush predator and active grasper; uses its feeding basket to quickly enclose prey upon contact.
Spawning substrate
Pelagic (eggs are carried in a brood chamber, resting eggs sink to the bottom).
Overwintering
Overwintering occurs in the egg stage as resting eggs (ephippia) on the lake bottom.
Ecology
Ecological role
Important secondary consumer and top predator within the zooplankton community; significant prey for pelagic fish.
Natural predators
Planktivorous fish such as coregonids (whitefish), bleaks, and perch; also predatory insect larvae.
Competitor species
Other predatory zooplankton such as Bythotrephes longimanus.
Ecosystem service
Regulation of zooplankton population density; part of the energy flow to higher trophic levels (fisheries).
Threats
Climate change (lake warming), invasive species, and severe eutrophication.
Scientific profile
Profile
Distinguishing features
Largest native cladoceran species; features a single, large, spherical compound eye at the head; the second antennae are modified into large rowing organs; six pairs of thoracic appendages for grasping.
Reproduction
Cyclical parthenogenesis (heterogony); asexual reproduction in summer, sexual reproduction in autumn to produce resting eggs.