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Starfish Wasting Disease
Sea star wasting disease or starfish wasting syndrome is a disease of starfish and several other echinoderms that appears sporadically, causing mass mortality of those affected. There are approximately 40 species of sea stars that have been affected by this disease. At least 20 of these species were on the Northwestern coast of Mexico to Alaska. The disease seems to be associated with increased water temperatures in some locales, but not others. It starts with the emergence of lesions, followed by body fragmentation and death. In 2014, it was suggested that the disease is associated with a single-stranded DNA virus now known as the sea star-associated densovirus (SSaDV). However, this hypothesis was refuted by recent research in 2018 and 2020. Sea star wasting disease is still not fully understood. Symptoms Typically the first symptom of sea star wasting disease is refusal to accept food followed by listlessness for weeks and then white lesions that appear on the surface of the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dying Purple Ochre Sea Star
Dying is the final stage of life which will eventually lead to death. Diagnosing dying is a complex process of clinical decision-making, and most practice checklists facilitating this diagnosis are based on cancer diagnoses. Signs of dying The National Cancer Institute in the United States advises that the presence of some of the following signs may indicate that death is approaching: * Drowsiness, increased sleep, and/or unresponsiveness (caused by changes in the patient's metabolism). * Confusion about time, place, and/or identity of loved ones; restlessness; visions of people and places that are not present; pulling at bed linens or clothing (caused in part by changes in the patient's metabolism). * Decreased socialization and withdrawal (caused by decreased oxygen to the brain, decreased blood flow, and mental preparation for dying). * Decreased need for food and fluids, and loss of appetite (caused by the body's need to conserve energy and its decreasing ability to us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pycnopodia Helianthoides
''Pycnopodia helianthoides'', commonly known as the sunflower sea star, is a large starfish, sea star found in the northeastern Pacific Ocean. The only species of its genus, it is among the largest sea stars in the world, with a maximum arm span of . Adult sunflower sea stars usually have 16 to 24 limbs. They vary in color. Sunflower sea stars are predatory and carnivorous, feeding mostly on sea urchins, clams, sea snails, and other small invertebrates. Although the species was widely distributed throughout the northeast Pacific, its population rapidly declined from 2013. The sunflower sea star is classified as Critically Endangered on the International Union for Conservation of Nature, IUCN IUCN Red List, Red List. Description Sunflower sea stars can reach an arm span of . They are the heaviest known sea star, weighing about 5 kg. They are the second-biggest sea star in the world, second only to the little known deep water ''Midgardia xandaros'', whose arm span is and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles Times
The ''Los Angeles Times'' is an American Newspaper#Daily, daily newspaper that began publishing in Los Angeles, California, in 1881. Based in the Greater Los Angeles city of El Segundo, California, El Segundo since 2018, it is the List of newspapers in the United States, sixth-largest newspaper in the U.S. and the largest in the Western United States with a print circulation of 118,760. It has 500,000 online subscribers, the fifth-largest among U.S. newspapers. Owned by Patrick Soon-Shiong and published by California Times, the paper has won over 40 Pulitzer Prizes since its founding. In the 19th century, the paper developed a reputation for civic boosterism and opposition to Trade union, labor unions, the latter of which led to the Los Angeles Times bombing, bombing of its headquarters in 1910. The paper's profile grew substantially in the 1960s under publisher Otis Chandler, who adopted a more national focus. As with other regional newspapers in California and the United Sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sperm
Sperm (: sperm or sperms) is the male reproductive Cell (biology), 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 testicles. This process involves the production of several successive sperm cell precursors, starting with spermatogonia, which Cellular differentiation, differentiate into spermatocytes. The spermatocytes then undergo meiosis, reducing their Ploidy, chromosome number by half, which produces spermatids. The sper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orchitophrya Stellarum
''Orchitophrya stellarum'' is a species of single-celled marine ciliates, a member of the class Oligohymenophorea. It is found living freely in the north Atlantic and Pacific Oceans but is also parasitic, being found inside the gonads of starfish. Biology ''Orchitophrya stellarum'' tolerates a sea temperature range of between and and a salinity range of between 2 and at least 30 parts per thousand of salt equivalent. The lower the temperature, the lower the acceptable level of salinity. Growth is most rapid at 24 °C. It is a facultative parasite of sea stars in the Asteriidae family. It seems to be able to survive in the open sea indefinitely as long as there is a supply of bacteria and tissue detritus on which it can feed. Parasitism ''Orchitophrya stellarum'' is often associated with sea stars and other invertebrates, living on their outer surface and feeding on sloughed-off epidermal tissue. It only appears to become parasitic when the male host starfish has ripe gona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protozoa
Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically, protozoans were regarded as "one-celled animals". When first introduced by Georg Goldfuss, in 1818, the taxon Protozoa was erected as a class within the Animalia, with the word 'protozoa' meaning "first animals", because they often possess animal-like behaviours, such as motility and predation, and lack a cell wall, as found in plants and many algae. This classification remained widespread in the 19th and early 20th century, and even became elevated to a variety of higher ranks, including phylum, subkingdom, kingdom, and then sometimes included within the paraphyletic Protoctista or Protista. By the 1970s, it became usual to require that all taxa be monophyletic (derived from a common ancestor that would also be regarded as protozo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cilia
The cilium (: cilia; ; in Medieval Latin and in anatomy, ''cilium'') is a short hair-like membrane protrusion from many types of eukaryotic cell. (Cilia are absent in bacteria and archaea.) The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids; they are longer than cilia and have a different undulating motion. There are two major classes of cilia: ''motile'' and ''non-motile'' cilia, each with two subtypes, giving four types in all. A cell will typically have one primary cilium or many motile cilia. The structure of the cilium core, called the axoneme, determines the cilium class. Most motile cilia have a central pair of single microtubules surrounded by nine pairs of double microtubules called a 9+2 axoneme. Most non-motile cilia have a 9+0 axoneme that lacks the central pai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Warming
Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, deforestation, and some agricultural and industrial practices release greenhouse gases. These gases absorb some of the heat that the Earth radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary gas driving global warming, has increased in concentration by about 50% since the pre-industrial era to levels not seen for millions of years. Climate change has an increasingly large impact on the environment. Deserts are expanding, while heat waves and wildfires are becoming more common. Amplified warming in the Arctic has c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathogen
In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of disease, germ. The term ''pathogen'' came into use in the 1880s. Typically, the term ''pathogen'' is used to describe an ''infectious'' microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. Small animals, such as helminths and insects, can also cause or Transmission (medicine), transmit disease. However, these animals are usually referred to as parasites rather than pathogens. The scientific study of microscopic organisms, including microscopic pathogenic organisms, is called microbiology, while parasitology refers to the scientific study of parasites and the organisms that host them. There are several pathways through which pathogens can invade a host. The principal pathways have different episodic time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Bridges State Marine Reserve
Natural Bridges State Marine Reserve (SMR) is a marine protected area located at the northern edge of Santa Cruz, California, approximately south of San Francisco. The SMR covers . The SMR protects all marine life within its boundaries. Fishing or other removal of any living marine resource is prohibited. History The California Department of Fish and Game established the Natural Bridges State Marine Reserve in September 2007. It was one of 29 marine protected areas adopted during the first phase of the Marine Life Protection Act Initiative (MLPAI), a collaborative public process to create a statewide network of marine protected areas along the California coastline. Geography and natural features Natural Bridges SMR is adjacent to Natural Bridges State Beach and Wilder Ranch State Park. The marine protected area is bounded by the mean high tide line and a distance of seaward of mean lower low water between the following two points: * 36° 57.90’ N. lat. 122° 07.65’ W. l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dermasterias Imbricata
The leather star (''Dermasterias imbricata'') is a sea star in the family Asteropseidae found at depths to off the western seaboard of North America. It was first described to science by Adolph Eduard Grube in 1857. Description The leather star has a broad central disc and five plump, short arms which taper broadly from the central disc. The arms have two rows of tube feet and no bordering marginal plates. The upper, aboral, surface is smooth and velvety, made more so by the absence of spines and a light layer of mucous. It is covered with a reticulated pattern in reddish-brown, often with patches of greyish-blue. No pedicellariae are present, but the madreporite can be seen. This starfish can grow to about in diameter and has a distinctive smell that resembles garlic and sulphur.Marine Biodiversity of British Columbia [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patiria Miniata
''Patiria miniata'', the bat star, sea bat, webbed star, or broad-disk star, is a species of sea star (also called a starfish) in the family Asterinidae. It typically has five arms, with the center disk of the animal being much wider than the stubby arms are in length. Although the bat star usually has five arms, it sometimes has as many as nine. Bat stars occur in many colors, including green, purple, red, orange, yellow and brown, either mottled or solid. The bat star gets its name from the webbing between its arms, which is said to resemble a bat's wings. The bat star is usually found in the intertidal zone to a depth of . Its range extends from Sitka, Alaska to Baja California in the Pacific Ocean. It is most abundant along the Central Coast of California. Classification The genus of this species has transitioned back and forth between '' Asterina'' and ''Patiria'' since its inclusion in Fisher's 1911 North Pacific Asteroidea monograph. However, recent revisions based on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
