Slender cyclops
Metacyclops gracilis
The slender cyclops is a small representative of the Cyclopoida, characterized by a particularly slender body shape. It prefers stagnant small water bodies, ditches, and the littoral zones of larger lakes, usually among aquatic vegetation. The species is widely distributed in Europe but is sensitive to the destruction of small water habitats. Like other cyclopoid species, it moves with characteristic jerky swimming motions.
Details
Identification
Body very slender; first antennae short (11 segments); endopodites of swimming legs two-segmented; furcal rami about 3 times as long as wide.
Social behavior
Solitary, but often occurs in high population densities in suitable habitats.
Diet
Omnivorous; feeds on organic detritus, algae, bacteria, and protozoa.
Hunting strategy
Filter feeder and raptorial feeder of small particles and microorganisms from the water.
Spawning substrate
Eggs are carried in paired sacs attached to the abdomen of the female.
Overwintering
Overwintering usually in the sediment as a larval stage (copepodid) or as resting eggs.
Ecology
Ecological role
Important primary and secondary consumer; serves as an essential food source for fish larvae and predatory macrozoobenthos.
Natural predators
Juvenile fish, predatory insect larvae (e.g., dragonfly larvae), water mites.
Competitor species
Other cyclopoid species and cladocerans (water fleas).
Ecosystem service
Contributes to the self-purification of water bodies by decomposing organic matter.
Threats
Loss of small water bodies, eutrophication, use of insecticides in agriculture.
Scientific profile
Profile
Distinguishing features
Characterized by an 11-segmented first antenna (A1). The 5th leg (P5) is highly reduced: the basal segment is fused with the thoracic segment, and the single free segment bears a terminal spine and a seta. Furcal rami are approximately 3 to 4 times as long as wide. The endopodites of the 4th swimming legs are slender.
Reproduction
Sexual reproduction; females carry two laterally arranged egg sacs. Development proceeds through six naupliar and five copepodid stages to the adult.
Role in food web
Secondary consumer; important trophic bridge between the microbial loop (protozoa) and higher predators such as fish.
Protection & threats
Status not on standard scale
Main threats
Loss and drainage of small water bodies, eutrophication due to agricultural runoff, and chemical pollution from pesticides.