Vesikilnikke

Vesikilnikke is a Finnish term that translates to "water flea" or "water louse" in English. It refers to a diverse group of small, planktonic crustaceans belonging to the order Cladocera. These tiny invertebrates are commonly found in freshwater environments worldwide, including lakes, ponds, rivers, and slow-moving streams.

Despite their common name, vesikilnikke are not true fleas or lice, but rather small crustaceans related to shrimp and crabs. They typically range in size from 0.2 to 5 millimeters and are characterized by their transparent or translucent bodies, which often reveal their internal organs. Many species possess a distinct carapace that covers their body but not their head, and they move using a pair of antennae.

Vesikilnikke play a crucial role in aquatic ecosystems. They are primary consumers, feeding on algae, bacteria, and organic detritus. In turn, they serve as a vital food source for a wide range of aquatic organisms, including small fish, insect larvae, and other invertebrates. Their populations can fluctuate significantly, often responding to changes in water quality, temperature, and food availability. Some species are also used as indicators of water pollution due to their sensitivity to environmental changes. Their life cycle often involves parthenogenesis, where females reproduce asexually, and sexual reproduction can occur under stressful conditions.