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Anemonia Sulcata
''Anemonia sulcata'', or Mediterranean snakelocks sea anemone, is a species of sea anemone in the family Actiniidae from the Mediterranean Sea. Whether ''A. sulcata'' should be recognized as a synonym of '' A. viridis'' remains a matter of dispute. Description This sea anemone has two ecotypes; one has a basal disk up to in diameter and has fewer than 192 tentacles (usually 142 to 148); the other has a disk up to in diameter and 192 tentacles or more, up to 348. The tentacles are long, slender and tapering, arranged in six whorls round the central mouth on the oral disk. They vary in colour but are usually some shade of green, grey or light brown. A knob on the tip of each tentacle, where the stinging cells are concentrated, may be violet. Distribution and habitat This sea anemone is native to the Mediterranean Sea and the eastern Atlantic Ocean as far south as Western Sahara. It is found in the intertidal zone and the sublittoral zone, on rocky ledges, in crevices and on b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argelès-sur-Mer
Argelès-sur-Mer (, literally ''Argelès on Sea''; ca, Argelers de la Marenda or ; oc, Argelers de Mar), commonly known as Argelès, is a commune in the Pyrénées-Orientales department in the administrative region of Occitania, France. It is about 25 km from Perpignan. Geography Argelès-sur-Mer is located in the canton of La Côte Vermeille and in the arrondissement of Céret. Argelès-sur-Mer is on the Côte Vermeille at the foot of the Albères mountain range, close to the Spanish border. It has the longest beach in the Pyrenées Orientales. History During World War II, Argelès-sur-Mer was the location of a concentration camp, where up to 100,000 defeated Spanish Republicans were interned next to a windy beach in abysmal sanitary conditions by the French government after the defeat of the Spanish Republic. The refugees streamed to the camp from the winter of 1938/39 after the collapse of the Catalan front following the rebel offensive. Government and politics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals have a type of gonad called an ovotestis. Evolution It is hard to find a common origin for gonads, but gonads most likely evolved independently several times. Regulation The gonads are controlled by luteinizing hormone and follicle-stimulating hormone, produced and secreted by gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone produced in the hypothalamus. Development Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of genital ridges, which are only l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cádiz (province)
Cádiz (, , ) is a city and port in southwestern Spain. It is the capital of the Province of Cádiz, one of eight that make up the autonomous community of Andalusia. Cádiz, one of the oldest continuously inhabited cities in Western Europe, was founded by the Phoenicians.Strabo, ''Geographica'' 3.5.5 In the 18th century, the Port in the Bay of Cádiz consolidated as the main harbor of mainland Spain, enjoying the virtual monopoly of trade with the Americas until 1778. It is also the site of the University of Cádiz. Situated on a narrow slice of land surrounded by the sea‚ Cádiz is, in most respects, a typically Andalusian city with well-preserved historical landmarks. The older part of Cádiz, within the remnants of the city walls, is commonly referred to as the Old Town (Spanish: ''Casco Antiguo''). It is characterized by the antiquity of its various quarters (''barrios''), among them ''El Pópulo'', ''La Viña'', and ''Santa María'', which present a marked contras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seafood
Seafood is any form of sea life regarded as food by humans, prominently including fish and shellfish. Shellfish include various species of molluscs (e.g. bivalve molluscs such as clams, oysters and mussels, and cephalopods such as octopus and squid), crustaceans (e.g. shrimp, crabs, and lobster), and echinoderms (e.g. sea cucumbers and sea urchins). Historically, marine mammals such as cetaceans (whales and dolphins) as well as seals have been eaten as food, though that happens to a lesser extent in modern times. Edible sea plants such as some seaweeds and microalgae are widely eaten as sea vegetables around the world, especially in Asia. Seafood is an important source of (animal) protein in many diets around the world, especially in coastal areas. Semi-vegetarians who consume seafood as the only source of meat are said to adhere to pescetarianism. The harvesting of wild seafood is usually known as fishing or hunting, while the cultivation and farming of seafood is kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ortiguillas De Mar098
The snakelocks anemone (''Anemonia viridis'') is a sea anemone found in the eastern Atlantic Ocean and the Mediterranean Sea. The latter population is however sometimes considered a separate species, the Mediterranean snakelocks anemone (''Anemonia sulcata''). The tentacles are usually a deep green colour with purple tips, the green colour is often attributed to the presence of symbiotic algae within the tentacles but is actually the result of the presence of Green Fluorescent Protein which is present in corals, sea anemones, and some other cnidarians. The anemone tissue contains a symbiotic algae called zooxanthellae, which is necessary for the long-term survival of the sea anemone. When the numbers of algae diminish the anemone may appear dull grey in colour. The algae need light to flourish, so Snakelocks Anemones will be found in the sunniest pools. On average the snakelock anemone is 8 cm wide. Reproduction Unlike other cnidarians, anemones (and other Anthozoa) entire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal. Cellular death due to necrosis does not follow the apoptotic signal transduction pathway, but rather various receptors are activated and result in the loss of cell membrane integrity and an uncontrolled release of products of cell death into the extracellular space. This initiates in the surrounding tissue an inflammatory response, which attracts leukocytes and nearby phagocytes which eliminate the dead cells by phagocytosis. However, microbial damaging substances released by leukocytes would crea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnidocyte
A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this cell defines the phylum Cnidaria (corals, sea anemones, hydrae, jellyfish, etc.). Cnidae are used to capture prey and as a defense against predators. A cnidocyte fires a structure that contains a toxin within the cnidocyst; this is responsible for the stings delivered by a cnidarian. Structure and function Each cnidocyte contains an organelle called a cnida, cnidocyst, nematocyst, ptychocyst or spirocyst. This organelle consists of a bulb-shaped capsule containing a coiled hollow tubule structure attached to it. An immature cnidocyte is referred to as a cnidoblast or nematoblast. The externally oriented side of the cell has a hair-like trigger called a cnidocil, which is a mechano- and chemo-receptor. When the trigger is activated, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregating Anemone
The aggregating anemone (''Anthopleura elegantissima''), or clonal anemone, is the most abundant species of sea anemone found on rocky, tide swept shores along the Pacific coast of North America. This cnidarian hosts endosymbiotic algae called zooxanthellae that contribute substantially to primary productivity in the intertidal zone. The aggregating anemone has become a model organism for the study of temperate cnidarian-algal symbioses. Description The polyps of the aggregating anemone reach up to eight cm across the oral disk with approximately 100 tentacles in three or four rows around the margins of the oral disk. Most are olive to bright green (depending on the species of algal symbionts present) with tentacles tipped in pink. Individuals that live in microhabitats that are deficient in photosynthetically active radiation (PAR), such as under docks or in caves, lack symbionts and are pale yellow to white in color. Range Pacific coast of North America from Alaska, Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asexual Reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and eubacteria, bacteria. Many Eukaryote, eukaryotic organisms including plants, animals, and Fungus, fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Komodo dragons and some monitor lizards can also reproduce asexually. While all prokaryotes reproduce without the formation and fusion of gametes, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oocyte
An oocyte (, ), oöcyte, or ovocyte is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female gametogenesis. The female germ cells produce a primordial germ cell (PGC), which then undergoes mitosis, forming oogonia. During oogenesis, the oogonia become primary oocytes. An oocyte is a form of genetic material that can be collected for cryoconservation. Formation The formation of an oocyte is called oocytogenesis, which is a part of oogenesis. Oogenesis results in the formation of both primary oocytes during fetal period, and of secondary oocytes after it as part of ovulation. Characteristics Cytoplasm Oocytes are rich in cytoplasm, which contains yolk granules to nourish the cell early in development. Nucleus During the primary oocyte stage of oogenesis, the nucleus is called a germinal vesicle. The only normal human type of secondary oocyte has t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Column
A water column is a conceptual column of water from the surface of a sea, river or lake to the bottom sediment.Munson, B.H., Axler, R., Hagley C., Host G., Merrick G., Richards C. (2004).Glossary. ''Water on the Web''. University of Minnesota-Duluth. Retrieved 27 May 2014. Descriptively, the deep sea water column is divided into five parts—'' pelagic zones'' (from Greek πέλαγος (pélagos), 'open sea')—from the surface to below the floor, as follows: ''epipelagic'', from the surface to 200 meters below the surface; ''mesopelagic'', from 200 to 1000 meters below the surface; '' bathypelagic'', from 1000 to 4000 meters below the surface; ''abyssopelagic'', from 4000 meters below the surface to the level sea floor; ''hadopelagic'', depressions and crevices below the level sea floor. The concept of water column is useful since many aquatic phenomena are explained by the incomplete vertical mixing of waters with discrete chemical, physical or biological characteristics. Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Cavity
A body cavity is any space or compartment, or potential space, in an animal body. Cavities accommodate organs and other structures; cavities as potential spaces contain fluid. The two largest human body cavities are the ventral body cavity, and the dorsal body cavity. In the dorsal body cavity the brain and spinal cord are located. The membranes that surround the central nervous system organs (the brain and the spinal cord, in the cranial and spinal cavities) are the three meninges. The differently lined spaces contain different types of fluid. In the meninges for example the fluid is cerebrospinal fluid; in the abdominal cavity the fluid contained in the peritoneum is a serous fluid. In amniotes and some invertebrates the peritoneum lines their largest body cavity called the coelom. Mammals Mammalian embryos develop two body cavities: the intraembryonic coelom and the extraembryonic coelom (or chorionic cavity). The intraembryonic coelom is lined by somatic and splanchnic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
