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Polypterus Palmas
''Polypterus palmas'', also called the shortfin or marbled bichir, is a fish in the family Polypteridae found in freshwater environments throughout West Africa. Distribution ''P. palmas'' has a wide range; it can be found in freshwater environments at a demersal depth range in Ghana, Democratic Republic of Congo, Cameroon, Liberia, Guinea, Ivory Coast, and Sierra Leone. It was listed as "least concern" within this range by the IUCN in 2021. Description The maximum recorded length of ''P. palmas'' is 35.3 cm (13.9) inches, although lengths of around 30 cm (11.8 inches) are much more common. It can be distinguished from other similarly-sized bichirs such as ''Polypterus senegalus'' and '' Polypterus polli'' by its bright gold coloration, speckled pattern, and dark transverse barring. Two color morphs of this species exist—''P. palmas'' "palmas" is found in more Southern locales and has a more pale yellow body with thinner dark barring, while ''P. palmas'' "buettikoferi" is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Orville Ayres
William Orville Ayres (September 11, 1817 – April 30, 1887) was an American physician and ichthyologist. Born in Connecticut, he studied to become a doctor at Yale University School of Medicine. Life and career Ayers, the son of Jared and Dinah (Benedict) Ayres, was born in New Canaan, Conn, September 11, 1817. He graduated from Yale College in 1837. For fifteen years after graduation he was employed as a teacher as follows in Berlin, Conn. (1837–38), Miller's Place, L. I. (1838–41), East Hartford, Conn. (1842–44), Sag Harbor, L. I. (1844–47), and Boston, Mass (1845–52). He began the study of medicine in Boston, and in 1854 received the degree of M.D. from Yale College. He then removed to San Francisco, Cal., where he remained for nearly twenty years, engaged in practice. He also served as Professor of the Theory and Practice of Medicine in the Toland Medical College in that city. He removed to Chicago shortly before the great fire of 1871, in which he suffered co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypterus Mokelembembe
''Polypterus mokelembembe'' is a species of the fish genus ''Polypterus'', found in the central basin of the Congo River. It was once considered a morph of the closely related '' Polypterus retropinnis'', but was given species status in 2006 with a description that reclassified both fishes. Because of the recency of the species' description and the fact that ''P. mokelembembe'' is the paralectotype of ''P. retropinnis'', they are often mistaken for one another in the aquarium trade. Etymology The species was named after the Mokèlé-mbèmbé, a mythological creature believed by some to be a sauropod dinosaur that survived the extinction of dinosaurs in the central Congo Basin. This is in reference to the fact that Polypteriformes are stabilomorphic organisms, or "living fossils," and existed at the same time as non-avian dinosaurs, and the fact that ''P. mokelembembe'' is itself endemic to the Congo Basin. Description ''P. mokelembembe'' is the smallest extant Polypterid, reachin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypterus Polli
''Polypterus polli'', Poll's bichir, is a species of bichir from the Malebo Pool and the lower and central basins of the Congo River. It was named in honor of Belgian ichthyologist Max Poll. Description ''P. polli'' is an “upper-jaw” bichir, meaning its maxilla protrudes further out than its mandible. It has a maximum recorded length of 12.6 inches (32.1 cm). It can be distinguished from other bichirs by its dull gold body color, greenish-yellow fins, and reticulated body pattern with light-colored “polka-dots” toward the base of the tail. It is oftentimes mistaken for ''P. palmas'' in the aquarium trade because they were once considered conspecific and have a similar color pattern, but ''P. polli'' lacks the dark transverse barring and speckled look characteristic of both ''P. palmas'' morphs. It can also be distinguished by its count of 5-7 dorsal finlets. Bichirs are stabilomorphic fishes that diverged from other ray-finned fishes possibly as early as the Devonian perio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypterus Retropinnis
The West African bichir or retropinnis bichir (''Polypterus retropinnis''), is a freshwater fish in the family Polypteridae, is found in the central Congo River basin and Ogooué River in Africa. It is a long, slender fish that grows to a maximum length of about . Description Bichirs are primitive fish which have a jaw structure that resembles that of tetrapods rather than bony fishes; they also have rudimentary lungs and two slit-like spiracles used for exhalation, and can breathe air when there is insufficient oxygen in the water. The West African bichir has an elongated cylindrical body with a maximum length of . It can be distinguished from other members of the genus by having jaws that are about the same length, and in living specimens, having creamy-white irises speckled with black. The dorsal fin consists of 7 to 9 separate finlets each topped with a sharp spine. The pectoral fin is fleshy and has 30 to 32 soft rays and the anal fin has 12 to 15 spines. The dorsal surfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lungfish
Lungfish are freshwater vertebrates belonging to the order Dipnoi. Lungfish are best known for retaining ancestral characteristics within the Osteichthyes, including the ability to breathe air, and ancestral structures within Sarcopterygii, including the presence of lobed fins with a well-developed internal skeleton. Lungfish represent the closest living relatives of the tetrapods. Today there are only six known species of lungfish, living in Africa, South America, and Australia. The fossil record shows that lungfish were abundant since the Triassic. While vicariance would suggest this represents an ancient distribution limited to the Mesozoic supercontinent Gondwana, the fossil record suggests advanced lungfish had a widespread freshwater distribution and the current distribution of modern lungfish species reflects extinction of many lineages subsequent to the breakup of Pangaea, Gondwana and Laurasia. Lungfish have historically been referred to as salamanderfish, but this t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten extant salamander families are grouped together under the order Urodela. Salamander diversity is highest in eastern North America, especially in the Appalachian Mountains; most species are found in the Holarctic realm, with some species present in the Neotropical realm. Salamanders rarely have more than four toes on their front legs and five on their rear legs, but some species have fewer digits and others lack hind limbs. Their permeable skin usually makes them reliant on habitats in or near water or other cool, damp places. Some salamander species are fully aquatic throughout their lives, some take to the water intermittently, and others are entirely terrestrial as adults. This group of amphibians is capable of regenerating lost lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiracle (vertebrates)
Spiracles () are openings on the surface of some animals, which usually lead to respiratory systems. The spiracle is a small hole behind each eye that opens to the mouth in some fish. In the jawless fish, the first gill opening immediately behind the mouth is essentially similar to the other gill opening. With the evolution of the jaw in the early jawed vertebrates, this gill slit was caught between the forward gill-rod (now functioning as the jaw) and the next rod, the hyomandibular bone, supporting the jaw hinge and anchoring the jaw to the skull proper. The gill opening was closed off from below, the remaining opening was small and hole-like, and is termed a spiracle. In many species of sharks and all rays the spiracle is responsible for the intake of water into the buccal space before being expelled from the gills. The spiracle is often located towards the top of the animal allowing breathing even while the animal is mostly buried under sediments. As sharks adapted a faster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FishBase
FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.Marine Fellow: Rainer Froese ''Pew Environment Group''. Over time it has "evolved into a dynamic and versatile ecological tool" that is widely cited in scholarly publications. FishBase provides comprehensive species data, including information on , geographical distribution, and |
Living Fossil
A living fossil is an extant taxon that cosmetically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old relative to the time of origin of the extant clade. Living fossils commonly are of species-poor lineages, but they need not be. While the body plan of a living fossil remains superficially similar, it is never the same species as the remote relatives it resembles, because genetic drift would inevitably change its chromosomal structure. Living fossils exhibit stasis (also called "bradytely") over geologically long time scales. Popular literature may wrongly claim that a "living fossil" has undergone no significant evolution since fossil times, with practically no molecular evolution or morphological changes. Scientific investigations have repeatedly discredited such claims. The minimal superficial changes to living fossils are mistakenly declared as an absence of evolution, but they are examples of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
