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Percarina Demidoffi
Common percarina (''Percarina demidoffii'') is a species of fish in the family Percidae. It is found in northwestern Black Sea basin in estuaries and coastal lakes, and in the lower reaches of the rivers that drain into that part of the Black Sea. It is a carnivorous species. Description The common percarina is distinguished from its congener '' P. maeotica'' by having no scales on its cheek, by having nearly transparent membranes on the body and fins, the upper body is milky white in colour with no spots. It also has 8-9 round or irregular markings on the base of both dorsal fins. The dorsal fins are clearly separate in both species of ''Percarina and in this species the first dorsal fin contains 9-10 spines while the second dorsal fin contains 3 spines and 10-12 soft rays. The anal fin has 2 spines and 8-11 soft rays. this species has a maximum published standard length of . Distribution The common percarina is found in eastern Europe in the northwestern Black Sea where it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Von Nordmann
Alexander von Nordmann (24 May 1803 in Ruotsinsalmi (now Kotka), Finland – 25 June 1866 in Helsinki) was a 19th-century Finnish biologist, who contributed to zoology, parasitology, botany and paleontology.Leikola A (2001Nordmann, Alexander von (1803 - 1866) - eläintieteen professori, todellinen valtioneuvosKansallisbiografia. SKS Biografiakeskus Biography Nordmann was a son of an officer of the Russian army at the Ruotsinsalmi fortress, SE Finland. He started academic studies at the Imperial Academy of Turku, and at that time also acted as a curator of the entomological collections. In 1827 he continued studies in Berlin with the famous parasitologist and anatomist Karl Rudolphi. His first major work was a microscopical description of tens of parasitic worms and crustaceans from the eyes and other organs of fishes and other animals, including man. These included the enigmatic monogenean ''Diplozoon paradoxum''. In 1832 he was appointed a professor (teacher) at the Lyceum R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by currents in the ocean, or by currents in seas, lakes or rivers. Zooplankton can be contrasted with phytoplankton, which are the plant component of the plankton community ("phyto" comes from the Greek word for ''plant''). Zooplankton are heterotrophic (other-feeding), whereas phytoplankton are autotrophic (self-feeding). This means zooplankton cannot manufacture their own food but must eat other plants or animals instead — in particular they eat phytoplankton. Zooplankton are generally larger than phytoplankton, most are microscopic, but some (such as jellyfish) are macroscopic and can be seen with the naked eye. Many protozoans (single-celled protists that prey on other microscopic life) are zooplankton, including zooflagellates, fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Described In 1840
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
