Cyclops (genus)


Cyclops is one of the most common genera of freshwater copepods, comprising over 400 species. Together with other similar-sized non-copepod fresh-water crustaceans, especially cladocera, they are commonly called water fleas. The name Cyclops comes from the Cyclops of Greek mythology which shares the quality of having a single large eye, which may be either red or black in Cyclops.

Anatomy

Cyclops individuals may range from ½–5 mm long and are clearly divided into two sections. The broadly oval front section comprises the head and the first five thoracic segments. The hind part is considerably slimmer and is made up of the sixth thoracic segment and the four legless pleonic segments. Two caudal appendages project from the rear. Although they may be difficult to observe, Cyclops has 5 pairs of legs. The long first antennae, 2 in number, are used by the males for gripping the females during mating. Afterwards, the female carries the eggs in two small sacs on her body. The larvae, or nauplii, are free-swimming and unsegmented.

Habitat

Cyclops has a cosmopolitan distribution in fresh water, but is less frequent in brackish water. It lives along the plant-covered banks of stagnant and slow-flowing bodies of water, where it feeds on small fragments of plant material, animals, or carrion. It swims with characteristic jerky movements. Cyclops has the capacity to survive unsuitable conditions by forming a cloak of slime. Average lifespan is about 3 months.

Public health importance

Cyclops is intermediate host of dracunculiasis and fish tapeworm infection.

Control methods

Cyclops can be controlled using physical, chemical, biological and engineering methods.

Physical

Straining of water through piece of fine cloth is sufficient to remove Cyclops. It can also be killed by boiling water, as it is easily killed by heat at 60 °C.

Chemical

destroys Cyclops in strength of 22 ppm in 2 hours; although this concentration of chlorine gives bad odour and taste to water. Excess chlorine can be removed with Sodium thiosulfate. Calcium hydroxide at dosage of 4 gram per gallon of water can be used. Temefos kills cyclops at concentration of 1 mg/litre.

Biological

Small fish like barbel and Gambusia feed on Cyclops. This type of predation was used in Indian state of Karnataka to eradicate dracunculiasis.

Engineering

Provision of drinking water through piping water supply, use of tubewells and abolition of stepwells are effective measures on community level.

Species