Saw-toothed cyclops
Eucyclops serrulatus
The saw-toothed cyclops is a small copepod crustacean found in a wide variety of freshwater habitats, ranging from puddles to large lakes. It is specifically characterized by the distinctive saw-like serrations on the outer margins of its caudal rami. As a vital component of zooplankton, it serves as an essential food source for many fish species and predatory invertebrates.
Details
Identification
Row of fine saw-like denticles on the outer margins of the caudal rami; 12-segmented first antennae; two laterally projecting egg sacs in females.
Social behavior
Largely solitary, though often occurs in high population densities; social interaction is limited to mating.
Diet
Omnivorous; feeds on phytoplankton (algae), detritus, protozoans, and occasionally small rotifers.
Hunting strategy
Combination of active filtering of particles and seizing small prey organisms.
Spawning substrate
No substrate required, as eggs are carried in egg sacs attached to the female's body.
Overwintering
Overwintering as an adult or in the form of resting stages (diapause) within the bottom sediment.
Ecology
Ecological role
Important primary and secondary consumer; transfers energy from algae to higher trophic levels (fish).
Natural predators
Juvenile fish, predatory zooplankton, water bugs, dragonfly larvae, and water mites.
Competitor species
Other cyclopid species such as Cyclops vicinus or various Daphnia species.
Ecosystem service
Contributes to water purification by consuming algae and organic detritus.
Threats
Eutrophication through fertilizer runoff, pesticide pollution of water bodies, and destruction of small water habitats.
Scientific profile
Profile
Distinguishing features
Characteristic is the 'saw' (serra) on the outer margin of the furcal rami, consisting of a row of fine spinules. The first antennae (A1) have 12 segments and feature a hyaline membrane on the last three segments. The furcal rami are approximately 4 to 6 times as long as they are wide.
Reproduction
Sexual reproduction; females carry two egg-shaped sacs closely attached to the urosome. Development proceeds through naupliar and copepodid stages.
Role in food web
Important secondary consumer in the littoral zone; transforms energy from detritus and microalgae for higher trophic levels.
Protection & threats
Status not on standard scale
Main threats
Habitat loss through the filling of small water bodies, massive pesticide input from agriculture, and extreme acidification.