|
Pelmatosphaera Polycirri
''Pelmatosphaera'' is a monotypic genus of worm Worms are many different distantly related bilateria, bilateral animals that typically have a long cylindrical tube-like body, no limb (anatomy), limbs, and usually no eyes. Worms vary in size from microscopic to over in length for marine ...s belonging to the monotypic family Pelmatosphaeridae. The only species is ''Pelmatosphaera polycirri''. References Orthonectida Monotypic protostome genera {{Protostome-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Genus
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Worm
Worms are many different distantly related bilateria, bilateral animals that typically have a long cylindrical tube-like body, no limb (anatomy), limbs, and usually no eyes. Worms vary in size from microscopic to over in length for marine polychaete worms (bristle worms); for the African giant earthworm, ''Microchaetus rappi''; and for the marine nemertean worm (bootlace worm), ''Lineus longissimus''. Various types of worm occupy a small variety of parasitism, parasitic niches, living inside the bodies of other animals. Free-living worm species do not live on land but instead live in marine or freshwater environments or underground by burrowing. In biology, "worm" refers to an obsolete taxon, ''Vermes'', used by Carl Linnaeus, Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, now seen to be paraphyletic. The name stems from the Old English word ''wikt:wyrm, wyrm''. Most animals called "worms" are invertebrates, but the term is also use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthonectida
Orthonectida () is a small phylum (biology), phylum of poorly known parasites of marine invertebrates that are among the simplest of multi-cellular organisms. Members of this phylum are known as orthonectids. Biology The adults, which are the sexual stage, are microscopic wormlike animals, consisting of a single layer of ciliated outer cells surrounding a mass of sex cells. They swim freely within the bodies of their hosts, which include flatworms, polychaete worms, Bivalvia, bivalve molluscs, and echinoderms. Most are gonochorism, gonochoristic, with separate male and female individuals, but a few species are hermaphroditic. When they are ready to reproduce, adults leave the host, and sperm from the males penetrate the bodies of the females to achieve internal fertilisation. The resulting zygote develops into a ciliated larva that escapes from the mother to seek out new hosts. Once it finds a host, the larva loses its cilia and develops into a syncytium, syncytial Plasmodium (li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
