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Capniidae
The Capniidae, the small winter stoneflies, are a family of insects in the stonefly order (Plecoptera). It constitutes one of the largest stonefly families, containing some 300 species distributed throughout the holarctic. Their closest relatives are the rolled-winged stoneflies (Leuctridae). Many species are endemic to small ranges, perhaps due to the family's tendency to evolve tolerance for cold (isolating populations in mountain valleys) and winglessness (inhibiting dispersal). Indeed, some wingless Capniidae – e.g. the Lake Tahoe benthic stonefly ('' "Capnia" lacustra'', ''Capnia'' is not monophyletic and this species is suspected to belong elsewhere) or '' Baikaloperla'' spp. – spend their entire lifecycles under water and do not disperse from their native lakes at all. Description and ecology Adult Capniidae, as their common name implies, are typically small Plecoptera; while most are less than 1 cm long with some measuring just 4 mm as adults, a fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capnia Lacustra
''Capnia lacustra'', also known as the Lake Tahoe benthic stonefly, is a species of insect in the family Capniidae. It was first described by S.G. Jewett in 1965. It belongs to the family Capniidae and is the only stonefly known to spend its entire adult life underwater. Description ''Capnia lacustra'' is a yellow-ish stonefly up to 5.5mm long that lacks both wings and external gills. It has long, filamentous antennae, paired abdominal cerci, and large compound eyes. Natural history Life cycle and behavior Unlike other stoneflies, ''Capnia lacustra'' adults do not leave the water to lay eggs. They have a univoltine life cycle and have been shown to exhibit facultative viviparity. Researchers have observed two distinct cohorts of ''Capnia lacustra'': one with viviparous Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stonefly
Plecoptera is an order of insects, commonly known as stoneflies. Some 3,500 species are described worldwide, with new species still being discovered. Stoneflies are found worldwide, except Antarctica. Stoneflies are believed to be one of the most primitive groups of Neoptera, with close relatives identified from the Carboniferous and Lower Permian geological periods, while true stoneflies are known from fossils only a bit younger. Their modern diversity, however, apparently is of Mesozoic origin. Plecoptera are found in both the Southern and Northern Hemispheres, and the populations are quite distinct, although the evolutionary evidence suggests species may have crossed the equator on a number of occasions before once again becoming geographically isolated. All species of Plecoptera are intolerant of water pollution, and their presence in a stream or still water is usually an indicator of good or excellent water quality. Description and ecology Stoneflies have a genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. The area occupied by the abdomen is called the abdominal cavity. In arthropods it is the posterior (anatomy), posterior tagma (biology), tagma of the body; it follows the thorax or cephalothorax. In humans, the abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint (the intervertebral disc between Lumbar vertebrae, L5 and Vertebra#Sacrum, S1) to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear. In vertebrates, the abdomen is a large body c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between organisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (evolution)
In phylogenetics, basal is the direction of the ''base'' (or root) of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a ' key innovation' implies some degree of correlation between evolutionary innovation and diversification. However, such a correlation does not make a given case predicable, so ancestral characters should not be imputed to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy (biology)
In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a more inclusive group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain, kingdom, phylum (''division'' is sometimes used in botany in place of ''phylum''), class, order, family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, as he developed a ranked system known as Linnaean taxonomy for categorizing organisms and binomial nomenclature for naming organisms. With advances in the theory, data and analytical technology of biological systematics, the Linnaean system has transformed into a system of modern biological classification intended to reflect the evolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systematics
Biological systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: cladograms, phylogenetic trees, phylogenies). Phylogenies have two components: branching order (showing group relationships) and branch length (showing amount of evolution). Phylogenetic trees of species and higher taxa are used to study the evolution of traits (e.g., anatomical or molecular characteristics) and the distribution of organisms (biogeography). Systematics, in other words, is used to understand the evolutionary history of life on Earth. The word systematics is derived from the Latin word '' systema,'' which means systematic arrangement of organisms. Carl Linnaeus used 'Systema Naturae' as the title of his book. Branches and applications In the study of biological systematics, researchers use the different branches to further understand the relationshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogeny
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a ''rooted'' phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics, systematics, and phylogenetics. ''Unrooted'' trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoological names with "-inae". See also * International Code of Nomenclature for algae, fungi, and plants * International Code of Zoological Nomenclature * Rank (botany) * Rank (zoology) In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species, genus, family, order, class, phylum, kingdom, domain. While ... Sources {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic
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. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, '' Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthos
Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.Benthos from the Census of Antarctic Marine Life website This community lives in or near marine or freshwater sedimentary environments, from s along the , out to the , and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
