|
Blackish Stingray
The blackish stingray, ''Hemitrygon navarrae'', is a little-known species of stingray in the family (biology), family Dasyatidae, found in the northwestern Pacific Ocean off the coasts of mainland China and Taiwan. This species reaches across and has a chocolate brown, diamond-shaped pectoral fin disc nearly as long as wide. Its whip-like tail bears three large tubercles in front of the stinging spine, as well as both Dorsum (anatomy), dorsal and ventral fin folds with the ventral fold half as long as the disc. Caught as bycatch in bottom trawls, the blackish stingray is frequently marketed as food in China. T Taxonomy Austrian zoologist Franz Steindachner originally described the blackish stingray as ''Trygon navarrae'', in an 1892 volume of the scientific journal ''Denkschriften der Mathematisch-Naturwissenschaftlichen Classe der Kaiserlichen Akademie der Wissenschaften in Wien''. The type specimen is a male across, collected from Shanghai, China.Nishida, K. and K. Nakaya (199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Steindachner
Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian Zoology, zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner described hundreds of new species of fish and dozens of new amphibians and reptiles. At least seven species of reptile have been named after him. Work and career Being interested in natural history, Steindachner took up the study of fossil fishes on the recommendation of his friend Eduard Suess (1831–1914). In 1860 he was appointed to the position of director of the fish collection at the Naturhistorisches Museum, a position which had remained vacant since the death of Johann Jakob Heckel (1790–1857). (in German). Steindachner's reputation as an Ichthyology, ichthyologist grew, and in 1868 he was invited by Louis Agassiz (1807–1873) to accept a position at the Museum of Comparative Zoology at Harvard University. Steindachner took ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shanghai
Shanghai (; , , Standard Mandarin pronunciation: ) is one of the four direct-administered municipalities of the People's Republic of China (PRC). The city is located on the southern estuary of the Yangtze River, with the Huangpu River flowing through it. With a population of 24.89 million as of 2021, Shanghai is the most populous urban area in China with 39,300,000 inhabitants living in the Shanghai metropolitan area, the second most populous city proper in the world (after Chongqing) and the only city in East Asia with a GDP greater than its corresponding capital. Shanghai ranks second among the administrative divisions of Mainland China in human development index (after Beijing). As of 2018, the Greater Shanghai metropolitan area was estimated to produce a gross metropolitan product (nominal) of nearly 9.1 trillion RMB ($1.33 trillion), exceeding that of Mexico with GDP of $1.22 trillion, the 15th largest in the world. Shanghai is one of the world's major centers for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commercial Fishing
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large-scale commercial fishing is also known as industrial fishing. The major fishing industries are not only owned by major corporations but by small families as well. In order to adapt to declining fish populations and increased demand, many commercial fishing operations have reduced the sustainability of their harvest by fishing further down the food chain. This raises concern for fishery managers and researchers, who highlight how further they say that for those reasons, the sustainability of the marine ecosystems could be in danger of collapsing. Commercial fishermen harvest a wide variety of animals. However, a very small number of species support the majority of the world ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplacental Viviparous
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop inside eggs that remain in the mother's body until they are ready to hatch. The young of some ovoviviparous amphibians, such as ''Limnonectes larvaepartus'', are born as larvae, and undergo further metamorphosis outside the body of the mother. Members of genera ''Nectophrynoides'' and ''Eleutherodactylus'' bear froglets, not only the hatching, but all the most conspicuous metamorphosis, being completed inside the body of the mother before birth. Among insects that depend on opportunistic exploitation of transient food sources, such as many Sarcophagidae and other carrion flies, and species such as many Calliphoridae, that rely on fresh dung, and parasitoids such as tachinid flies that depend on entering the host as soon as possible, the embr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monogenea
Monogeneans are a group of ectoparasitic flatworms commonly found on the skin, gills, or fins of fish. They have a direct lifecycle and do not require an intermediate host. Adults are hermaphrodites, meaning they have both male and female reproductive structures.L.A. Tubbsa et al. (2005). "Effects of temperature on fecundity in vitro, egg hatching and reproductive development of ''Benedenia seriolae'' and ''Zeuxapta seriolae'' (Monogenea) parasitic on yellowtail kingfish Seriola lalandi". ''International Journal for Parasitology''(35), 315–327. Some monogeneans are oviparous (egg-laying) and some are viviparous (live-bearing). Oviparous varieties release eggs into the water. Viviparous varieties release larvae, which immediately attach to another host. The genus ''Gyrodactylus'' is an example of a viviparous variety, while the genus ''Dactylogyrus'' is an example of an oviparous variety. Signs and symptoms Freshwater fish that become infected with this parasite become let ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copepod
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor), a number of species have parasitic phases, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, and puddles, damp moss, or water-filled recesses (phytotelmata) of plants such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods are sometimes used as Ecological indicator, biodiversity indicators. As with other crustaceans, copepods have a larval form. For copepods, the egg hatches into a Crustacean larvae#Nauplius, nauplius form, with a head and a tail but no true thorax or abdomen. The larva molts several times until it resembles the adult an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as Armillaria mellea, honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the Orobanchaceae, broomrapes. There are six major parasitic Behavioral ecology#Evolutionarily stable strategy, strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), wikt:trophic, trophicallytransmitted parasitism (by being eaten), Disease vector, vector-transmitted parasitism, parasitoidism, and micropreda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papilla (fish Mouth Structure)
The papilla, in certain kinds of fish, particularly rays, sharks, and catfish, are small lumps of dermal tissue found in the mouth, where they are "distributed uniformly on the tongue, palate, and pharynx".B. G. Kapoor, H. E. Evans, E. A. Pevzner "The gustatory system in fish" in ''Advances in Marine Biology, Volume 13'' (1976), F. S. Russell, Maurice Yonge (eds). They "project slightly above the surrounding multi-layered epithelium", and the taste buds of the fish are "situated along the crest or at the apex of the papillae". Unlike humans, fish have little or nothing in the way of a tongue The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ..., and those that have such an organ do not use it for tasting, but merely for cushioning the mouth and manipulating things within it. The papill ... [...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] |
Yellow River
The Yellow River or Huang He (Chinese: , Standard Beijing Mandarin, Mandarin: ''Huáng hé'' ) is the second-longest river in China, after the Yangtze River, and the List of rivers by length, sixth-longest river system in the world at the estimated length of . Originating in the Bayan Har Mountains in Qinghai province of Western China, it flows through nine provinces, and it empties into the Bohai Sea near the city of Dongying in Shandong province. The Yellow River basin has an east–west extent of about and a north–south extent of about . Its total drainage area is about . The Yellow River's basin was the Yellow River civilization, birthplace of ancient Chinese, and, by extension, Far East, Far Eastern civilization, and it was the most prosperous region in early Chinese history. There are frequent devastating natural disasters in China, floods and course changes produced by the continual elevation of the river bed, sometimes above the level of its surrounding farm fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estuary
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as bays, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "the depths." Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the shore line (intertidal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
