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Callorhinchus
''Callorhinchus'', the plough-nosed chimaeras or elephantfish, are the only living genus in the family Callorhinchidae (sometimes spelled Callorhynchidae). A few extinct genera only known from fossil remains are recognized. ''Callorhinchus'' spp, are similar in form and habits to other Chimaeriformes, chimaeras, but are distinguished by the presence of an elongated, flexible, fleshy snout, with a vague resemblance to a ploughshare. They are only found in the oceans of the Southern Hemisphere along the ocean bottom on muddy and sandy substrates. They filter feed, with small shellfish making up the bulk of their diet. The plough-nosed chimaera lays eggs on the ocean floor that hatch at around 8 months. They are currently not a target of conservation efforts; however, they may be susceptible to overfishing and trawling. Morphology Plough-nose chimaeras range from about in total length. Their usual color is black or brown, and, often a mixture between the two. While the club-like sn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callorhinchus Torresi
''Callorhinchus'', the plough-nosed chimaeras or elephantfish, are the only living genus in the family Callorhinchidae (sometimes spelled Callorhynchidae). A few extinct genera only known from fossil remains are recognized. ''Callorhinchus'' spp, are similar in form and habits to other Chimaeriformes, chimaeras, but are distinguished by the presence of an elongated, flexible, fleshy snout, with a vague resemblance to a ploughshare. They are only found in the oceans of the Southern Hemisphere along the ocean bottom on muddy and sandy substrates. They filter feed, with small shellfish making up the bulk of their diet. The plough-nosed chimaera lays eggs on the ocean floor that hatch at around 8 months. They are currently not a target of conservation efforts; however, they may be susceptible to overfishing and trawling. Morphology Plough-nose chimaeras range from about in total length. Their usual color is black or brown, and, often a mixture between the two. While the club-like sn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callorhinchus Milii
The Australian ghostshark (''Callorhinchus milii'') is a cartilaginous fish (Chondrichthyes) belonging to the subclass Holocephali (chimaera). Sharks, rays and skates are the other members of the cartilaginous fish group and are grouped under the subclass Elasmobranchii. Alternative names include elephant shark, ''makorepe'' (in Māori), whitefish, plough-nose chimaera, or elephant fish. It is found off southern Australia, including Tasmania, and south of East Cape and Kaipara Harbour in New Zealand, at depths of . Morphology and biology The fish is silvery in colour with iridescent reflections and dark, variable markings on the sides. Males mature at and females at , and the maximum length head to tail is . It has an elongated body, smooth and torpedo shaped with two widely separated, triangular dorsal fins. They use their hoe-shaped snouts to probe the ocean bottom for invertebrates and small fishes. From spring to autumn, adults migrate inshore to estuaries and bays and fema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian Ghostshark
The Australian ghostshark (''Callorhinchus milii'') is a cartilaginous fish (Chondrichthyes) belonging to the subclass Holocephali (chimaera). Sharks, rays and skates are the other members of the cartilaginous fish group and are grouped under the subclass Elasmobranchii. Alternative names include elephant shark, ''makorepe'' (in Māori language, Māori), whitefish, plough-nose chimaera, or elephant fish. It is found off southern Australia, including Tasmania, and south of East Cape and Kaipara Harbour in New Zealand, at depths of . Morphology and biology The fish is silvery in colour with iridescent reflections and dark, variable markings on the sides. Males mature at and females at , and the maximum length head to tail is . It has an elongated body, smooth and torpedo shaped with two widely separated, triangular dorsal fins. They use their hoe-shaped snouts to probe the ocean bottom for invertebrates and small fishes. From spring to autumn, adults migrate inshore to estuaries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callorhinchus Callorynchus
''Callorhinchus callorynchus'', the American elephantfish or cockfish, is a species of fish in the family Callorhinchidae found in southern Brazil, Peru, Chile, Argentina, and Uruguay. Its natural habitat is open seas. Being a holocephalan from the southwestern region of the Atlantic, ''C. callorynchus'' is a vital resource for fisheries in Argentina. A study was conducted on the reproductive biology of the cockfish by Melisa A. Chierichetti from UNMDP, which found that there was a presence of sexual dimorphism, where the females were larger and heavier than the males of that population. Another aspect of this study had discovered that the relative fecundity rate of the ''C. callorynchus'' population was significantly low because the females were in the resting stage of their reproductive cycle. Also, the males in the population weren't mature, thus the population was found to not be highly reproductive. This information was expected to be helpful in implementing methods for cons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Elephantfish
The Cape elephantfish, josef, or St Joseph shark (''Callorhinchus capensis'') is a species of fish in the family Callorhinchidae.Branch, G.M., Branch, M.L, Griffiths, C.L. and Beckley, L.E. 2010. ''Two Oceans: a guide to the marine life of southern Africa'' Description The Cape elephantfish is a smooth silvery or bronze fish which grows to 120 cm in total length, with a digging proboscis on the front of its snout. The first dorsal fin has a large venomous spine in front of it. There are darker markings on the flanks and head. At maturity, the males have a pair of calcified claspers, paired retractable prepelvic graspers, and a door-knocker-like projection (tentaculum) on their heads. Distribution It is found off the coasts of Namibia and South Africa inshore and down to 374 m. Ecology The Cape elephantfish eats sea urchins, bivalves, crustaceans, gastropods, worms, and bony fish. Its predators include seals and sharks. It is oviparous, laying two egg cases at a time. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callorhinchus Capensis
The Cape elephantfish, josef, or St Joseph shark (''Callorhinchus capensis'') is a species of fish in the family Callorhinchidae.Branch, G.M., Branch, M.L, Griffiths, C.L. and Beckley, L.E. 2010. ''Two Oceans: a guide to the marine life of southern Africa'' Description The Cape elephantfish is a smooth silvery or bronze fish which grows to 120 cm in total length, with a digging proboscis on the front of its snout. The first dorsal fin has a large venomous spine in front of it. There are darker markings on the flanks and head. At maturity, the males have a pair of calcified claspers, paired retractable prepelvic graspers, and a door-knocker-like projection (tentaculum) on their heads. Distribution It is found off the coasts of Namibia and South Africa inshore and down to 374 m. Ecology The Cape elephantfish eats sea urchins, bivalves, crustaceans, gastropods, worms, and bony fish. Its predators include seals and sharks. It is oviparous, laying two egg cases at a time. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocephali
Holocephali ("complete heads"), sometimes given the term Euchondrocephali, is a subclass of cartilaginous fish in the class Chondrichthyes. The earliest fossils are of teeth and come from the Devonian period. Little is known about these primitive forms, and the only surviving group in the subclass is the order Chimaeriformes. Chimaeriformes, commonly known as chimaeras, includes the rat fishes in the genus '' Chimaera'', and the elephant fishes in the genus ''Callorhinchus''. These fishes move by using sweeping movements of their large pectoral fins. They are deep sea fish with slender tails, living close to the seabed to feed on benthic invertebrates. They lack a stomach, their food moving directly into the intestine. Extinct holocephalans were much more diverse in lifestyles, including shark-like predatory forms and slow, durophagous fish. Characteristics Members of this taxon preserve today some features of elasmobranch life in Paleozoic times, though in other respects th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleost
Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts ), is, by far, the largest infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of all extant species of fish. Teleosts are arranged into about 40 orders and 448 family (biology), families. Over 26,000 species have been described. Teleosts range from giant oarfish measuring or more, and ocean sunfish weighing over , to the minute male anglerfish ''Photocorynus spiniceps'', just long. Including not only torpedo-shaped fish built for speed, teleosts can be flattened vertically or horizontally, be elongated cylinders or take specialised shapes as in anglerfish and seahorses. The difference between teleosts and other bony fish lies mainly in their jaw bones; teleosts have a movable premaxilla and corresponding modifications in the jaw musculature which make it possible for them to cranial kinesis, protrude their jaws outwards from the mouth. This is of ... [...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] |
Forebrain
In the anatomy of the brain of vertebrates, the forebrain or prosencephalon is the Anatomical terms of location#Directional terms, rostral (forward-most) portion of the brain. The forebrain (prosencephalon), the midbrain (mesencephalon), and hindbrain (rhombencephalon) are the three Brain vesicle, primary brain vesicles during the early development of the nervous system. The forebrain controls body temperature, reproductive functions, eating, sleeping, and the display of emotions. At the five-vesicle stage, the forebrain separates into the diencephalon (thalamus, hypothalamus, subthalamus, and epithalamus) and the telencephalon which develops into the cerebrum. The cerebrum consists of the cerebral cortex, underlying white matter, and the basal ganglia. In humans, by 5 weeks in utero it is visible as a single portion toward the front of the fetus. At 8 weeks in utero, the forebrain splits into the left and right cerebral hemispheres. When the embryonic forebrain fails to divide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellum
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebellum plays an important role in motor control. It may also be involved in some cognition, cognitive functions such as attention and language as well as emotion, emotional control such as regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to Motor coordination, coordination, precision, and accurate timing: it receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine-tune motor activity. Cerebellar damage produces disorders in Fine motor skill, fine movement, Equilibrioception, equilibrium, Human positions, posture, and motor learning in humans. Anatomica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oviparous
Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and monotremes. In traditional usage, most insects (one being ''Culex pipiens'', or the common house mosquito), molluscs, and arachnids are also described as oviparous. Modes of reproduction The traditional modes of reproduction include oviparity, taken to be the ancestral condition, traditionally where either unfertilised oocytes or fertilised eggs are spawned, and viviparity traditionally including any mechanism where young are born live, or where the development of the young is supported by either parent in or on any part of their body. However, the biologist Thierry Lodé recently divided the traditional category of oviparous reproduction into two modes that he named ovuliparity and (true) oviparity respectively. He distinguished the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
