|
Pacific Ocean Perch
The Pacific ocean perch (''Sebastes alutus''), also known as the Pacific rockfish, Rose fish, Red bream or Red perch, is a fish whose range spans across the North Pacific : from southern California around the Pacific rim to northern Honshū, Japan, including the Bering Sea. The species appears to be most abundant in northern British Columbia, the Gulf of Alaska, and the Aleutian Islands . Taxonomy The Pacific ocean perch was first formally described as ''Sebastichthys alutus'' in 1890 by the American ichthyologist Charles Henry Gilbert with the type locality given as the Santa Barbara Islands off California. Some authorities place this species in the subgenus ''Acutomentum''. The specific name ''alutus'' means "unwashed" thought to be an allusion to the dusky color with dark blotches along the back. Distribution, habitat and migration The Pacific ocean perch is found in the North Pacific Ocean where its range extends from Honshu in Japan to Cape Navarin in the Bering Sea, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Henry Gilbert
Charles Henry Gilbert (December 5, 1859 in Rockford, Illinois – April 20, 1928 in Palo Alto, California) was a pioneer ichthyologist and Fisheries science, fishery biologist of particular significance to natural history of the western United States. He collected and studied fishes from Central America north to Alaska and described many new species. Later he became an expert on Pacific salmon and was a noted conservation movement, conservationist of the Pacific Northwest. He is considered by many as the intellectual founder of American fisheries biology. He was one of the 22 "pioneer professors" (founding faculty) of Stanford University. Early life and education Born in Rockford, Illinois, Gilbert spent his early years in Indianapolis, Indiana, where he came under the influence of his high school teacher, David Starr Jordan (1851‒1931). When Jordan became Professor of Natural History at Butler University in Indianapolis, Gilbert followed and received his B.A. degree in 187 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Jolla
La Jolla ( , ) is a hilly, seaside neighborhood within the city of San Diego, California, United States, occupying of curving coastline along the Pacific Ocean. The population reported in the 2010 census was 46,781. La Jolla is surrounded on three sides by ocean bluffs and beaches and is located north of Downtown San Diego and south of the Orange County, California, Orange County line. The climate is mild, with an average daily temperature of . La Jolla is home to many educational institutions and a variety of businesses in the areas of lodging, dining, shopping, software, finance, real estate, bioengineering, medical practice and scientific research. The University of California, San Diego (UCSD) is located in La Jolla, as are the Salk Institute for Biological Studies, Salk Institute, Scripps Institution of Oceanography (part of UCSD), Scripps Research Institute, and the headquarters of National University (California), National University (though its academic campuses are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sperm
Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, which are known as spermatozoa, while some red algae and fungi produce non-motile sperm cells, known as spermatia. Flowering plants contain non-motile sperm inside pollen, while some more basal plants like ferns and some gymnosperms have motile sperm. Sperm cells form during the process known as spermatogenesis, which in amniotes ( reptiles and mammals) takes place in the seminiferous tubules of the testes. This process involves the production of several successive sperm cell precursors, starting with spermatogonia, which differentiate into spermatocytes. The spermatocytes then undergo meiosis, reducing their chromosome number by half, which produces spermatids. The spermatids then mature and, in animals, construct a tail, or flagellum, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertilization
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Processes such as insemination or pollination which happen before the fusion of gametes are also sometimes informally called fertilisation. The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation. History In Antiquity, Aristotle conceived the formation of new individuals through fusion of male and female fluids, with form and function emerging gradually, in a mode called by him as epigenetic. In 1784, Spallanzani established the need of interaction between the female's ovum and male's sperm to form a zygote in frog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viviparous
Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the mother. The term 'viviparity' and its adjective form 'viviparous' derive from the Latin ''vivus'' meaning "living" and ''pario'' meaning "give birth to". Reproductive mode Five modes of reproduction have been differentiated in animals based on relations between zygote and parents. The five include two nonviviparous modes: ovuliparity, with external fertilisation, and oviparity, with internal fertilisation. In the latter, the female lays zygotes as eggs with a large yolk; this occurs in all birds, most reptiles, and some fishes. These modes are distinguished from viviparity, which covers all the modes that result in live birth: *Histotrophic viviparity: the zygotes develop in the female's oviducts, but find their nutrients by oophagy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sebastidae
Sebastinae is a subfamily of marine fish belonging to the family Scorpaenidae in the order Scorpaeniformes. Their common names include rockfishes, rock perches, ocean perches, sea perches, thornyheads, scorpionfishes, sea ruffes and rockcods. Despite the latter name, they are not closely related to the cods in the genus ''Gadus'', nor the rock cod, ''Lotella rhacina''. Taxonomy Sebastinae, or Sebastidae, was first formally recognised as a grouping in 1873 by the German naturalist Johann Jakob Kaup. Some authorities recognise this family as distinct from Scorpaenidae. FishBase, a finfish database generated by a consortium of academic institutions, does, but the United States Federal government's Integrated Taxonomic Information System and the 5th Edition of ''Fishes of the World'' do not, FotW classify it as a subfamily of the Scorpaenidae. Tribes and genera Sebastinae is divided into two tribes and seven genera: * Tribe Sebastini Kaup, 1873 ** ''Helicolenus'' Goode & Bean, 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawl
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear. The boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from small open boats with as little as 30 hp (22 kW) engines to large factory trawlers with over 10,000 hp (7.5 MW). Trawling can be carried out by one trawler or by two trawlers fishing cooperatively ( pair trawling). Trawling can be contrasted with trolling. While trawling involves a net and is typically done for commercial usage, trolling instead involves a reed, rod and a bait or a lure and is typically done for recreational purposes. Trawling is also commonly used as a scientific sampling, or survey, method. Bottom vs. midwater trawlin ... [...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] |
Euphausiid
Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian word ', meaning "small fry of fish", which is also often attributed to species of fish. Krill are considered an important trophic level connection – near the bottom of the food chain. They feed on phytoplankton and (to a lesser extent) zooplankton, yet also are the main source of food for many larger animals. In the Southern Ocean, one species, the Antarctic krill, ''Euphausia superba'', makes up an estimated biomass of around 379,000,000 tonnes, making it among the species with the largest total biomass. Over half of this biomass is eaten by whales, seals, penguins, seabirds, squid, and fish each year. Most krill species display large daily vertical migrations, thus providing food for predators near the surface at night and in deeper waters during the day. Krill are fished commercially in the Southern Ocean and in the waters around Jap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelagic
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom. Conditions in the water column change with depth: pressure increases; temperature and light decrease; salinity, oxygen, micronutrients (such as iron, magnesium and calcium) all change. Marine life is affected by bathymetry (underwater topography) such as the seafloor, shoreline, or a submarine seamount, as well as by proximity to the boundary between the ocean and the atmosphere at the ocean surface, which brings light for photosynthesis, predation from above, and wind stirring up waves and setting currents in motion. The pelagic zone refers to the open, free waters away from the shore, where marine life can swim freely in any direction unhindered by topographical constraints. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demersal
The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of the larger profundal zone. Being just above the ocean floor, the demersal zone is variable in depth and can be part of the photic zone where light can penetrate, and photosynthetic organisms grow, or the aphotic zone, which begins between depths of roughly and extends to the ocean depths, where no light penetrates. Fish The distinction between demersal species of fish and pelagic species is not always clear cut. The Atlantic cod (''Gadus morhua'') is a typical demersal fish, but can also be found in the open water column, and the Atlantic herring (''Clupea harengus'') is predominantly a pelagic species but forms large aggregations near the seabed when it spawns on banks of gravel. Two types of fish inhabit the demersal zone: those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spawn (biology)
Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquatic mammals and marine reptile, reptiles, reproduce through the process of spawning. Spawn consists of the reproductive cells (gametes) of many aquatic animals, some of which will become fertilized and produce offspring. The process of spawning typically involves females releasing Ovum, ova (unfertilized eggs) into the water, often in large quantities, while males simultaneously or sequentially release spermatozoa (milt) to fertilize the eggs. Most fish reproduce by spawning, as do most other aquatic animals, including crustaceans such as crabs and shrimps, molluscs such as oysters and squid, echinoderms such as sea urchins and sea cucumbers, amphibians such as frogs and newts, aquatic insects such as mayflies and mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> La Jolla")
