The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for special senses such as vision, hearing and olfaction. Being the most specialized organ, it is responsible for receiving information from the sensory nervous system, processing those information and the coordination of motor control.
The zebrafish 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.
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral to caudal axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain, though precursor structures exist in onychophorans, gastropods and lancelets.
Cyprinidae is a family of freshwater fish commonly called the carp or minnow family, including the carps, the true minnows, and their relatives the barbs and barbels, among others. Cyprinidae is the largest and most diverse fish family, and the largest vertebrate animal family overall, with about 3,000 species; only 1,270 of these remain extant, divided into about 200 valid genera. Cyprinids range from about 12 mm (0.5 in) in size to the 3 m (9.8 ft) giant barb. By genus and species count, the family makes up more than two-thirds of the ostariophysian order Cypriniformes. The family name is derived from the Greek word kyprînos.
The cerebrum, telencephalon or endbrain is the largest part of the brain, containing the cerebral cortex as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In the human brain, the cerebrum is the uppermost region of the central nervous system. The cerebrum develops prenatally from the forebrain (prosencephalon). In mammals, the dorsal telencephalon, or pallium, develops into the cerebral cortex, and the ventral telencephalon, or subpallium, becomes the basal ganglia. The cerebrum is also divided into approximately symmetric left and right cerebral hemispheres.
The red nucleus or nucleus ruber is a structure in the rostral midbrain involved in motor coordination. The red nucleus is pale pink, which is believed to be due to the presence of iron in at least two different forms: hemoglobin and ferritin. The structure is located in the midbrain tegmentum next to the substantia nigra and comprises caudal magnocellular and rostral parvocellular components. The red nucleus and substantia nigra are subcortical centers of the extrapyramidal motor system.
The habenula is a small bilateral neuronal structure in the brain of vertebrates, that has also been called a microstructure since it is no bigger than a pea. The naming as little rein describes its elongated shape in the epithalamus, where it borders the third ventricle, and lies in front of the pineal gland.
Danionella is a genus of danionin fish found in freshwater habitats in Myanmar and West Bengal, India. It includes some of the smallest fishes.
Ampullae of Lorenzini are electroreceptors, sense organs able to detect electric fields. They form a network of mucus-filled pores in the skin of cartilaginous fish and of basal bony fishes such as reedfish, sturgeon, and lungfish. They are associated with and evolved from the mechanosensory lateral line organs of early vertebrates. Most bony fishes and terrestrial vertebrates have lost their ampullae of Lorenzini.
Danionella translucida is an extremely small species of cyprinid fish endemic to Myanmar. When described, it was considered to be one of the smallest fish. It was collected from the roots of floating aquatic plants in a slow-flowing, shallow stream in the Pegu Division of Myanmar. It was found alongside Danio, Microrasbora, Erethistes, and Oryzias species. Observed in life, D. translucida is almost perfectly transparent except for its eyes. It has a distinctive pattern of melanophores. There are no melanophores on the dorsal surface except on the head over the posterior part of the brain. On the posterior half of the body, there a few melanophores following the horizontal midline. The sides and underside of the abdomen have melanophores. A double row of melanophores is present on the underside of the fish from the isthmus of the gills to the pelvic fins. Eggs in D. translucida has been found to range in size from about 0.3–0.6 mm (0.012–0.024 in) in diameter, with ripe eggs being at least 0.5 mm (0.020 in) in diameter. Females carried anywhere from 3 to 8 or 10 eggs. Compared to the body of the fish, these eggs are relatively large.
Paedocypris is a genus of tiny cyprinid fish found in swamps and streams on the Southeast Asian islands of Borneo, Sumatra and Bintan.
Genes in the DLX family encode homeodomain transcription factors related to the Drosophiladistal-less(Dll) gene. The family has been related to a number of developmental features such as jaws and limbs. The family seems to be well preserved across species. As DLX/Dll are involved in limb development in most of the major phyla, including vertebrates, it has been suggested that Dll was involved in appendage growth in an early bilaterial ancestor.
The retrosplenial cortex (RSC) is a cortical area in the brain comprising Brodmann areas 29 and 30. It is secondary association cortex, making connections with numerous other brain regions. The region's name refers to its anatomical location immediately behind the splenium of the corpus callosum in primates, although in rodents it is located more towards the brain surface and is relatively larger. Its function is currently not well understood, but its location close to visual areas and also to the hippocampal spatial/memory system suggest it may have a role in mediating between perceptual and memory functions, particularly in the spatial domain. However, its exact contribution to either space or memory processing has been hard to pin down.
The dracula fish is a species of tropical danionin fish from the cyprinid family. It is a freshwater fish endemic to Myanmar. A close relative is Danio rerio, the zebrafish of aquariums. It is named dracula after its unusual "fangs"; male dracula fish have protruding tooth-like bones stemming from their jawbones. Males have been observed using their fangs to spar with other males.
The danionins are a group of small, minnow-type fish belonging to the family Cyprinidae. Species of this group are in the genera clades Danio and Devario, based on the latest phylo-genetic research by Fang et al in 2009. They are primarily native to the fresh waters of South and Southeast Asia, with fewer species in Africa. Many species are brightly coloured and are available as aquarium fish worldwide. Fishes of the danio clade tend to have horizontal stripes, rows of spots, or vertical bars, and often have long barbels. Species within the devario clade tend to have vertical or horizontal bars, and short, rudimentary barbels, if present at all. All danionins are egg scatterers, and breed in the rainy season in the wild. They are carnivores, living on insects and small crustaceans.
Family with Sequence Similarity 203, Member B (FAM203B) is a protein encoded by the FAM203B gene (8q24.3) in humans. While FAM203B is only found in humans and possibly non-human primates, its paralog, FAM203A, is highly conserved. The FAM203B protein contains two conserved domains of unknown function, DUF383 and DUF384, and no transmembrane domains. This protein has no known function yet, although the homolog of FAM203A in Caenorhabditis elegans (Y54H5A.2) is thought to help regulate the actin cytoskeleton.
Neurogenesis is the process by which nervous system cells, the neurons, are produced by neural stem cells (NSCs). This occurs in all species of animals except the porifera (sponges) and placozoans. Types of NSCs include neuroepithelial cells (NECs), radial glial cells (RGCs), basal progenitors (BPs), intermediate neuronal precursors (INPs), subventricular zone astrocytes, and subgranular zone radial astrocytes, among others.
In embryology a phylotypic stage or phylotypic period is a particular developmental stage or developmental period during mid-embryogenesis where embryos of related species within a phylum express the highest degree of morphological and molecular resemblance. Recent molecular studies in various plant and animal species were able to quantify the expression of genes covering crucial stages of embryo development and found that during the morphologically defined phylotypic period the evolutionary oldest genes, genes with similar temporal expression patterns, and genes under strongest purifying selection are most active throughout the phylotypic period.
Aenigmachanna is a genus of ray-finned fish in the order Ananbantiformes. It is the only genus in the family Aenigmachannidae, or dragon snakeheads. It contains two species, both of which are largely restricted to subterranean habitats in southwestern India, namely in the Western Ghats foothills in the state of Kerala.
