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Weberian Organ
The Weberian apparatus is an anatomical structure that connects the swim bladder to the auditory system in fishes belonging to the superorder Ostariophysi. When it is fully developed in adult fish, the elements of the apparatus are sometimes collectively referred to as the Weberian ossicles. The presence of the structure is one of the most important and phylogenetically significant distinguishing characteristics of the Ostariophysi. The structure itself consists of a set of minute bones that originate from the first few vertebrae to develop in an embryonic ostariophysan. These bones grow to physically connect the auditory system, specifically the inner ear, to the swim bladder. The structure acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone. Structural anatomy and function The generalized structure of the Weberian apparatus is akin to a skeletal complex of bones and ossicles that are physically connected to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontogeny
Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the study of the entirety of an organism's lifespan. Ontogeny is the developmental history of an organism within its own lifetime, as distinct from phylogeny, which refers to the evolutionary history of a species. Another way to think of ontogeny is that it is the process of an organism going through all of the developmental stages over its lifetime. The developmental history includes all the developmental events that occur during the existence of an organism, beginning with the changes in the egg at the time of fertilization and events from the time of birth or hatching and afterward (i.e., growth, remolding of body shape, development of secondary sexual characteristics, etc.). While developmental (i.e., ontogenetic) processes can influence sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swim Bladder
The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their current water depth without having to expend energy in swimming. Also, the Dorsum (biology), dorsal position of the swim bladder means the center of mass is below the centroid, center of volume, allowing it to act as a stabilizing agent. Additionally, the swim bladder functions as a resonator, resonating chamber, to produce or receive sound. The swim bladder is evolutionarily Homology (biology), homologous to the lungs. Charles Darwin remarked upon this in ''On the Origin of Species''.Darwin, Charles (1859''Origin of Species''Page 190, reprinted 1872 by D. Appleton. Darwin reasoned that the lung in air-breathing vertebrates had derived from a more primitive swim bladder. In the embryonic stages, some species, such as Ophioblennius atlanticus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleural Cavity
The pleural cavity, pleural space, or interpleural space is the potential space between the pleurae of the pleural sac that surrounds each lung. A small amount of serous pleural fluid is maintained in the pleural cavity to enable lubrication between the membranes, and also to create a pressure gradient. The serous membrane that covers the surface of the lung is the visceral pleura and is separated from the outer membrane the parietal pleura by just the film of pleural fluid in the pleural cavity. The visceral pleura follows the fissures of the lung and the root of the lung structures. The parietal pleura is attached to the mediastinum, the upper surface of the diaphragm, and to the inside of the ribcage. Structure In humans, the left and right lungs are completely separated by the mediastinum, and there is no communication between their pleural cavities. Therefore, in cases of a unilateral pneumothorax, the contralateral lung will remain functioning normally unless there is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area and the seventh most populous. Its capital is Brasília, and its most populous city is São Paulo. The federation is composed of the union of the 26 States of Brazil, states and the Federal District (Brazil), Federal District. It is the largest country to have Portuguese language, Portuguese as an List of territorial entities where Portuguese is an official language, official language and the only one in the Americas; one of the most Multiculturalism, multicultural and ethnically diverse nations, due to over a century of mass Immigration to Brazil, immigration from around the world; and the most populous Catholic Church by country, Roman Catholic-majority country. Bounded by the Atlantic Ocean on the east, Brazil has a Coastline of Brazi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santanichthys Diasii
''Santanichthys diasii'' is a species of extinct fish that existed around 115 million years ago during the Albian age. ''S. diasii'' is regarded as the basal-most characiform, and is the earliest known member of Otophysi. It appears as a small fish, similar in appearance to a modern-day herring little more than 30 millimeters in length. Its most striking characteristic is the presence of a Weberian apparatus, which makes it the most primitive known member of the order Characiformes, the order in which modern-day tetras (including piranhas) are classified. ''Santanichthys'' has been unearthed from numerous locations throughout Brazil, in rocks dating to the Cretaceous Period. Its presence in these strata is seen as an indicator for the biogeography and evolution of its order. Anatomy and morphology ''Santanichthys'' is a small, characiform fish that would have superficially resembled more advanced tetras or the unrelated herrings. Maximum length appears to be around 3-4 centime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corydoras Paleatus
''Corydoras paleatus'' is a species of catfish ( order Siluriformes) of the family Callichthyidae. Its common names include blue leopard corydoras, mottled corydoras, and peppered catfish. It originates from the lower Paraná River basin and coastal rivers in Uruguay and Brazil. Description This fish species reach about 5.9 centimeters (2.3 in) SL. The male is smaller than the female, and in proportion to body length, the dorsal fin and pectoral fins are longer on the male than the female. Ecology Corydoras paleatus is found in the Amazon basin, and feeds on worms, crustaceans, insects, and plant matter. ''C. paleatus'' has been known to produce sound; it does this by the abduction of its pectoral fins. This is used by males during courtship and intrapersonal communication, and by both sexes and juveniles when distressed. In reproduction, males do not behave aggressively toward each other, nor do they monopolize mating areas or females. The T-position is involved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhaphiodon Vulpinus
The biara (''Rhaphiodon vulpinus'') is a South American piscivorous fish in the dogtooth characin family. It belongs to the monotypic genus ''Rhaphiodon'', although some minor differences in morphometrics and colour are known from across its large range.OPEFE: Rhaphiodon.' Retrieved 13 January 2017.SeriouslyFish: Rhaphiodon vulpinus.' Retrieved 13 January 2017. It is found in the Amazon, Orinoco, and Río de la Plata Basins, as well as rivers of the Guianas. It occurs in a wide range of freshwater habitats such as main river channels, flooded forests, lakes and reservoirs. Some populations are migratory. It reaches up to in weight. Although it reportedly can reach up to in standard length, the largest confirmed were . Like other dogtooth characins, the biara has very long pointed canine teeth In mammalian oral anatomy, the canine teeth, also called cuspids, dog teeth, or (in the context of the upper jaw) fangs, eye teeth, vampire teeth, or vampire fangs, are the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Danio Rerio
The zebrafish (''Danio rerio'') is a freshwater fish belonging to the minnow family (Cyprinidae) of the order Cypriniformes. Native to South Asia, it is a popular aquarium fish, frequently sold under the trade name zebra danio (and thus often called a "tropical fish" although both tropical and subtropical). It is also found in private ponds. The zebrafish is an important and widely used vertebrate model organism in scientific research, for example in drug development, in particular pre-clinical development. It is also notable for its regenerative abilities, and has been modified by researchers to produce many transgenic strains. Taxonomy The zebrafish is a derived member of the genus '' Brachydanio'', of the family Cyprinidae. It has a sister-group relationship with ''Danio aesculapii''. Zebrafish are also closely related to the genus ''Devario'', as demonstrated by a phylogenetic tree of close species. Distribution Range The zebrafish is native to fresh water hab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homology (biology)
In biology, homology is similarity due to shared ancestry between a pair of structures or genes in different taxa. A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of primates, the front flippers of whales and the forelegs of four-legged vertebrates like dogs and crocodiles are all derived from the same ancestral tetrapod structure. Evolutionary biology explains homologous structures adapted to different purposes as the result of descent with modification from a common ancestor. The term was first applied to biology in a non-evolutionary context by the anatomist Richard Owen in 1843. Homology was later explained by Charles Darwin's theory of evolution in 1859, but had been observed before this, from Aristotle onwards, and it was explicitly analysed by Pierre Belon in 1555. In developmental biology, organs that developed in the embryo in the same manner and from similar origins, such as from matching p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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