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Any of various small, chiefly freshwater flatworms of the order Tricladida, having a soft, broad, ciliated body, a three-branched digestive cavity, and the ability to regenerate body parts.

[From New Latin Plānāria, genus name, from feminine of Late Latin plānārius, on level ground, from plānus, flat; see pelə- in Indo-European roots.]


(Animals) any free-living turbellarian flatworm of the mostly aquatic suborder Tricladida, having a three-branched intestine
[C19: from New Latin Plānāria type genus, from Late Latin plānārius level, flat; see plane1]


(pləˈnɛər i ən)

any of various free-swimming, mostly freshwater flatworms, having an undulating or sluglike motion.
[1885–60; < New Latin Planari(a) a flatworm genus (n. use of feminine of Late Latin plānārius level, on level ground; taken to mean “flat”; see plane1, -ary) + -an1]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.planarian - free-swimming mostly freshwater flatwormsplanarian - free-swimming mostly freshwater flatworms; popular in laboratory studies for the ability to regenerate lost parts
flatworm, platyhelminth - parasitic or free-living worms having a flattened body
class Turbellaria, Turbellaria - free-living flatworms
References in periodicals archive ?
The antiproliferative effect of chelidonine was also observed in HepG2 cells, in planarian stem cells and MCF-7 cells (Noureini et al.
29] shifted the point duration to 1 ms, they found that this pulse duration produced complete fragmentation and dissolution of planarian when they were exposed to combinations of this field and the Thomas pattern.
Even amongst planarian flatworms, famous for their ability to regenerate from random tissue fragments, species exist that have completely lost the ability to regenerate.
Holland died in the original explosion, Holland has always been dead, and what he is--rather, what it is--is a plant, a plant who consumed Holland's identity like a planarian worm.
The study, entitled "zic-1 Expression in Planarian Neoblasts after Injury Controls Anterior Pole Regeneration," was reported in PLOS Genetics.
Certain water-dwelling organisms, including hydra, planarian flatworms, tardigrades, and Turritopsis jellyfish, also pass the hundred-year mark with ease.
Localization of mitochondrial ribosomal RNA on the chromatoid bodies of marine planarian polyclad embryos.
Jacob, who also won a full four-year scholarship to the University of Massachusetts at Boston, studied the eyespots of planarian (freshwater flatworms) before and after regeneration for his project, Getting NERVEous.
Scientists at the park are monitoring the pink planarian.