Long-spined rotifer
Kellicottia longispina
Kellicottia longispina is a widespread freshwater rotifer primarily inhabiting the pelagic zones of lakes and reservoirs. It is characterized by a slender, spindle-shaped body and extremely long, immovable spines used for defense against predators. The species is an essential component of the aquatic food web, feeding mainly as a filter feeder on microalgae and detritus. Due to its unique morphology, it is easily distinguished from other rotifer genera under a microscope.
Details
Identification
Features one anterior median spine and one posterior spine, both of which are nearly as long as or longer than the body; the lorica is smooth and transparent.
Social behavior
Lives solitarily in the pelagic zone but can form mass developments under favorable conditions.
Diet
Feeds on fine organic material, bacteria, and small phytoplankton (e.g., chrysophytes).
Hunting strategy
Passive filter feeder that creates a water current towards the mouth using ciliary movement.
Spawning substrate
Eggs are usually carried on the body or released into the open water.
Overwintering
Overwinters either as an active form in deep, cold water or through the production of resting eggs.
Ecology
Ecological role
Important primary consumer that transfers energy from microparticles to higher trophic levels such as larval fish.
Natural predators
Predatory zooplankton (e.g., Asplanchna, cyclopoids) and planktivorous fish.
Competitor species
Other rotifers of the genus Keratella as well as small cladocerans.
Ecosystem service
Contributes to water clarification by filtering suspended particles.
Threats
Water eutrophication, invasive species, and drastic changes in temperature regimes.
Scientific profile
Profile
Distinguishing features
Features six anterior spines of unequal length (the central one is nearly as long as the body) and a single, very long posterior spine. The total length is significantly determined by these spines, which serve as a defense mechanism against predators (cyclopoids).
Reproduction
Predominantly heterogonic; mostly parthenogenetic reproduction by amictic females. Males appear only briefly under stress conditions.
Role in food web
Primary consumer; acts as a transformer of microbial biomass and nanoplankton for higher trophic levels.
Protection & threats
Status not on standard scale
Main threats
Anthropogenic eutrophication, chemical pollution of water bodies, and climate change (alteration of thermal stratification).