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Rouleina Attrita
The softskin smooth-head (''Rouleina attrita''), also called the softskin slickhead, is a species of fish in the family Alepocephalidae. Its specific name is from the Latin ''attrīta'' ("bruised, worn away"), presumably referring to the mutilated or decomposed state of the type specimens. Description The softskin smooth-head is black, measuring up to . Its upper jaw reaches to behind the eye, and it has a lateral line of 43–48 photophores. It has 43–46 vertebrae. Its scales are deciduous and its skin contains small fluid-filled compartments. Its eyes contain convexiclivate Temporal bone, temporal Fovea centralis, foveae containing densely packed ganglia. Habitat The softskin smooth-head is engybenthic or bathypelagic, meaning that it swims near the seafloor, living at depths of . It has been recorded in all non-polar seas. Behaviour Its testes are ribbon-like, in convoluted folds but never in discrete Lobe (anatomy), lobes. Its fish egg, eggs are large, up to in diamet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Léon Vaillant
Léon Louis Vaillant (; 11 November 1834 – 24 November 1914) was a French zoologist. He is most famous for his work in the areas of herpetology, malacology, and ichthyology. In 1854 he graduated from the College d'Arras, followed by studies in medicine and zoology in Paris. In 1861, he received his medical doctorate, then continued his zoological studies with Henri Milne-Edwards (1800-1885), earning his degree in natural sciences in 1865. In 1875, he became a professor at the Museum of Natural History in Paris. He held a special interest involving the systematics and anatomy of turtles and crocodiles, but also made significant contributions in his investigations of reptilian physiology and behavior. Of his 200-plus scientific writings, 90 of them are based on herpetological subjects. He participated in French naval expeditions on the ''Travailleur'' in 1880, 1881 and 1882 and on the ''Talisman'' in 1883. Eponyms The following are several species of marine organisms named ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fovea Centralis
The fovea centralis is a small, central pit composed of closely packed cones in the eye. It is located in the center of the macula lutea of the retina. The fovea is responsible for sharp central vision (also called foveal vision), which is necessary in humans for activities for which visual detail is of primary importance, such as reading and driving. The fovea is surrounded by the ''parafovea'' belt and the ''perifovea'' outer region. The parafovea is the intermediate belt, where the ganglion cell layer is composed of more than five layers of cells, as well as the highest density of cones; the perifovea is the outermost region where the ganglion cell layer contains two to four layers of cells, and is where visual acuity is below the optimum. The perifovea contains an even more diminished density of cones, having 12 per 100 micrometres versus 50 per 100 micrometres in the most central fovea. That, in turn, is surrounded by a larger peripheral area, which delivers highly compres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platytroctidae
The tubeshoulders are a family, Platytroctidae, of ray-finned fish belonging to the order Alepocephaliformes Alepocephaliformes is an order of ray-finned fish. It was previously classified as the suborder Alepocephaloidei of the order Argentiniformes The Argentiniformes are an order of ray-finned fish whose distinctness was recognized only fairly .... They are found throughout the world, except for the Mediterranean Sea. Tubeshoulders live at moderate depths of , and some have light-producing organs. They are generally small to medium fish, ranging from in length. Genera The family contains the following genera: * '' Barbantus'' * '' Holtbyrnia'' * '' Matsuichthys'' * '' Maulisia'' * '' Mentodus'' * '' Mirorictus'' * '' Normichthys'' * '' Pectinantus'' * '' Persparsia'' * '' Platytroctes'' * '' Sagamichthys'' * '' Searsia'' * '' Searsioides'' * '' Vachalia'' References * Ray-finned fish families {{Alepocephaliformes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the animal hatches. Most arthropods such as insects, vertebrates (excluding live-bearing mammals), and mollusks lay eggs, although some, such as scorpions, do not. Reptile eggs, bird eggs, and monotreme eggs are laid out of water and are surrounded by a protective shell, either flexible or inflexible. Eggs laid on land or in nests are usually kept within a warm and favorable temperature range while the embryo grows. When the embryo is adequately developed it hatches, i.e., breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark and was in size. Whale shark eggs typically hatch within the mother. At and up to , the ostric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobe (anatomy)
In anatomy, a lobe is a clear anatomical division or extension of an organ (as seen for example in the brain, lung, liver, or kidney) that can be determined without the use of a microscope at the gross anatomy level. This is in contrast to the much smaller lobule, which is a clear division only visible under the microscope. Interlobar ducts connect lobes and interlobular ducts connect lobules. Examples of lobes *The four main lobes of the brain **the frontal lobe **the parietal lobe **the occipital lobe **the temporal lobe *The three lobes of the human cerebellum **the flocculonodular lobe **the anterior lobe **the posterior lobe *The two lobes of the thymus *The two and three lobes of the lungs **Left lung: superior and inferior **Right lung: superior, middle, and inferior *The four lobes of the liver **Left lobe of liver **Right lobe of liver **Quadrate lobe of liver **Caudate lobe of liver *The renal lobes of the kidney *Earlobes Examples of lobules *the cortical lobules o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testes
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testosterone. Testosterone release is controlled by the anterior pituitary luteinizing hormone, whereas sperm production is controlled both by the anterior pituitary follicle-stimulating hormone and gonadal testosterone. Structure Appearance Males have two testicles of similar size contained within the scrotum, which is an extension of the abdominal wall. Scrotal asymmetry, in which one testicle extends farther down into the scrotum than the other, is common. This is because of the differences in the vasculature's anatomy. For 85% of men, the right testis hangs lower than the left one. Measurement and volume The volume of the testicle can be estimated by palpating it and comparing it to ellipsoids of known sizes. Another method is to use cali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathypelagic
The bathypelagic zone or bathyal zone (from Greek βαθύς (bathýs), deep) is the part of the open ocean that extends from a depth of below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The bathypelagic is known as the midnight zone because of the lack of sunlight; this feature does not allow for photosynthesis-driven primary production, preventing growth of phytoplankton or aquatic plants. Although larger by volume than the photic zone, our knowledge of the bathypelagic zone remains limited by our ability to explore the deep ocean. Physical characteristics The bathypelagic zone is characterized by a nearly constant temperature of approximately and a salinity range of 33-35 g/kg. This region has little to no light, because sunlight does not reach this deep in the ocean and bioluminescence is limited. The hydrostatic pressure in this zone ranges 100-400 atmospheres (atm), due to the increase of 1 atm for every 10 m depth. It is belie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganglia
A ganglion is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system there are both sympathetic and parasympathetic ganglia which contain the cell bodies of postganglionic sympathetic and parasympathetic neurons respectively. A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies. Structure Ganglia are primarily made up of somata and dendritic structures which are bundled or connected. Ganglia often interconnect with other ganglia to form a complex system of ganglia known as a plexus. Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems. Among vertebrates there are three major groups of ganglia: *Dorsal root ganglia (also known as the spinal ganglia) contain the cell bodies of se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Bone
The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. The lower seven cranial nerves and the major vessels to and from the brain traverse the temporal bone. Structure The temporal bone consists of four parts— the squamous, mastoid, petrous and tympanic parts. The squamous part is the largest and most superiorly positioned relative to the rest of the bone. The zygomatic process is a long, arched process projecting from the lower region of the squamous part and it articulates with the zygomatic bone. Posteroinferior to the squamous is the mastoid part. Fused with the squamous and mastoid parts and between the sphenoid and occipital bones lies the petrous part, which is shaped like a pyramid. The tympanic part is relatively small and lies inferior to the squamous part, anterior to the mast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrae
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank (i.e., location within the vertebral column, backbone), and on the other with phylogenetic differences among the vertebrate taxon, taxa. The basic configuration of a vertebra varies, but the bone is its ''body'', with the central part of the body constituting the ''centrum''. The upper (closer to) and lower (further from), respectively, the cranium and its central nervous system surfaces of the vertebra body support attachment to the intervertebral discs. The posterior part of a vertebra fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photophores
A photophore is a glandular organ that appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors, however unlike an eye it is optimized to produce light, not absorb it. The bioluminescence can variously be produced from compounds during the digestion of prey, from specialized mitochondrial cells in the organism called photocytes ("light producing" cells), or, similarly, associated with symbiotic bacteria in the organism that are cultured. The character of photophores is important in the identification of deep sea fishes. Photophores on fish are used for attracting food or for camouflage from predators by counter-illumination. Photophores are found on some cephalopods including the firefly squid, which can create impressive light displays, as well as numerous other deep sea organisms such as the pocket shark Mollisquama mississippien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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