Turtle Rotifer
Testudinella patina
The turtle rotifer is a widespread, microscopic freshwater animal belonging to the rotifer group. It is characterized by a circular, flat shape and a protective shell (lorica). Movement occurs smoothly via a ciliary corona at the head end. It prefers to live in stagnant waters among aquatic plants or in open water.
Details
Identification
Circular, flat lorica; foot emerges centrally on the ventral side; ciliated foot tip without toes; transparent body.
Social behavior
Usually lives solitarily in plankton or crawling on substrates such as duckweed.
Diet
Filters fine detritus particles, bacteria, and unicellular algae from the water.
Hunting strategy
Passive filter feeder using the ciliary corona.
Spawning substrate
Eggs are either carried freely in the water or deposited on plant parts.
Overwintering
Formation of thick-walled resting eggs (cysts) when environmental conditions deteriorate.
Ecology
Ecological role
Important primary consumer that makes bacterial biomass and detritus available for higher trophic levels (e.g., fish larvae).
Natural predators
Predatory zooplankton, small invertebrates, and juvenile fish.
Competitor species
Other filter-feeding rotifers and small cladocerans.
Ecosystem service
Contributes to the self-purification of water bodies by consuming bacteria and detritus.
Threats
Extreme water pollution, desiccation of habitats (temporarily survivable via resting eggs).
Scientific profile
Profile
Distinguishing features
The foot opening (foramen) is located on the ventral side of the lorica, significantly removed from the posterior margin (roughly in the posterior third or towards the center). The foot is annulated and ends in a ciliated cup rather than toes. The lorica is typically smooth and transparent.
Reproduction
Heterogony: Parthenogenetic reproduction by amictic females for most of the year; under environmental stress, production of mictic females which form resting eggs after fertilization.
Role in food web
Important consumer in the microbial loop; transforms bacterial biomass and detritus into energy available for higher trophic levels (secondary consumers).
Protection & threats
Status not on standard scale
Main threats
Loss of shallow water zones and macrophyte stands due to shoreline stabilization; eutrophication and pesticide input into small water bodies.