Platyhelminthes

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Platyhelminthes

 [plat″ĭ-hel-min´thēz]
the flatworms, a phylum of acoelomate, dorsoventrally flattened, bilaterally symmetrical animals; it includes the classes cestoidea (tapeworms) and trematoda (flukes).

Plat·y·hel·min·thes

(plat'i-hel-min'thēz),
A phylum of flatworms that are bilaterally symmetric, flattened, and acelomate. There is no digestive tract in some platyhelminths (Cestoda), or the gut may be incomplete (without an anus), as in the Trematoda; most of the forms are hermaphroditic. There are three major classes, but the parasitic species of medical and veterinary importance are in the subclass Cestoda (the true tapeworms) of the class Cestoidea, and in the subclass Digenea (the digenetic flukes) of the class Trematoda.

Plat·y·hel·min·thes

(plat'i-hel-min'thēz)
A phylum of flatworms that are bilaterally symmetric, flattened, and acelomate. Parasitic species of medical importance are in the subclass Cestoda (the true tapeworms) of the class Cestoidea, and in the subclass Digenea (the digenetic flukes) of the class Trematoda.

Plat·y·hel·min·thes

(plat'i-hel-min'thēz)
A phylum of flatworms that are bilaterally symmetric, flattened, and acelomate.
References in periodicals archive ?
The first article to use molecular markers in phylogenetic studies on fish platyhelminthes parasites dated from 1991.
Although previous studies have already shown neuronal profiles containing various types of vesicles in neuropiles of the central ganglia in the platyhelminths (Sukhdeo & Sukhdeo, 1990; Terenina et al., 2009; Leksonboom et al., 2012b), the present study failed to disclose any such neuronal profiles abutting on the immunopositive neurons and their proximal processes, or to disclose such aggregations of vesicles at submembranous sites of the immunopositive neuronal proximal processes on which another neuronal process abuts.
There is little experimental evidence to suggest the functions of the various types of receptors found in Platyhelminthes but all functional interpretations of presumed sensory structures remain uncertain and are based solely on their distribution and ultrastructural anatomy and are therefore speculative.
Patterns of sexual reproduction among parasitic platyhelminths. Parasitology 86:99-120.
A peculiarity of Platyhelminthes in general and parasitic flatworms in particular is the absence of fossils.
Planarians are free-living freshwater flatworms belonging to the phylum Platyhelminthes. They have a primitive morphology with simple triploblastic bodies (based on body-plan categories).
- Adaptive plasticity, Cercomeria, Digenea, Eucestoda, evolutionary loss, macroevolution, Monogenea, morphological diversification, parasitic platyhelminths, phylogenetic system-
Originally identified in mammalian tissues, NO has been identified in the signaling cascades of many invertebrates such as coelenterates, platyhelminths, nematodes, annelids, molluscs, arthropods, echinoderms, and urochordates (Martinez, 1995; Midler, 1997).
A good example is the mariner which, by being functional in both germ lines and somatic cell lines, could infect many organisms, crossing several phyletic borders (arthropods, platyhelminths, nematodes, chordates), probably by splicing into viral or other pathogenic genomes.
The early emergence of platyhelminths is contradicted by the agreement between 18S r RNA and Hox genes data.
Oblique striation has been described for muscles of platyhelminths, nematodes, gastrotrichs, nematomorphs, priapulids, pogonophora, chaetognathes, annelids, molluscs, brachiopods, and an echinoderm (3-7, 9), and dense bodies are an obvious feature in all taxa.