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Holothuria Tubulosa
''Holothuria tubulosa'', the cotton-spinner or tubular sea cucumber, is a species of sea cucumber in the family Holothuriidae. It is the type species of the genus '' Holothuria'' and is placed in the subgenus ''Holothuria'', making its full name ''Holothuria (Holothuria) tubulosa''. Description ''Holothuria tubulosa'' grows to a length of between and , and a diameter of . It is roughly cylindrical with a flattened base on which there are three longitudinal rows of tube feet. It has a tough, leathery skin. The general colour is a shade of brown and the surface is covered with numerous dark-coloured, conical, thorn-like projections known as papillae. It often appears greyish, as it secretes a protective film of mucus to which bits of seaweed and sediment may adhere. It has a fringe of short, flattened tentacles around the mouth at the anterior end and an anus at the posterior end. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Friedrich Gmelin
, fields = , workplaces = University of GöttingenUniversity of Tübingen , alma_mater = University of Tübingen , doctoral_advisor = Philipp Friedrich GmelinFerdinand Christoph Oetinger , academic_advisors = , doctoral_students = Georg Friedrich HildebrandtFriedrich StromeyerCarl Friedrich KielmeyerWilhelm August LampadiusVasily Severgin , notable_students = , known_for = Textbooks on chemistry, pharmaceutical science, mineralogy, and botany , author_abbrev_bot = J.F.Gmel. , author_abbrev_zoo = Gmelin , influences = Carl Linnaeus , influenced = , relatives = Leopold Gmelin (son) , awards = Johann Friedrich Gmelin (8 August 1748 – 1 November 1804) was a German naturalist, botanist, entomologist, herpetologist, and malacologist. Education Johann Friedrich Gmelin was born as the eldest son of Philipp Friedrich Gmelin in 1748 in Tübingen. He studied medicine under his father at University of Tübingen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seabed
The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of the ocean is very deep, where the seabed is known as the abyssal plain. Seafloor spreading creates mid-ocean ridges along the center line of major ocean basins, where the seabed is slightly shallower than the surrounding abyssal plain. From the abyssal plain, the seabed slopes upward toward the continents and becomes, in order from deep to shallow, the continental rise, slope, and shelf. The depth within the seabed itself, such as the depth down through a sediment core, is known as the “depth below seafloor.” The ecological environment of the seabed and the deepest waters are collectively known, as a habitat for creatures, as the “benthos.” Most of the seabed throughout the world's oceans is covered in layers of marine sediments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commensalism
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit from each other; amensalism, where one is harmed while the other is unaffected; parasitism, where one is harmed and the other benefits, and parasitoidism, which is similar to parasitism but the parasitoid has a free-living state and instead of just harming its host, it eventually ends up killing it. The commensal (the species that benefits from the association) may obtain nutrients, shelter, support, or locomotion from the host species, which is substantially unaffected. The commensal relation is often between a larger host and a smaller commensal; the host organism is unmodified, whereas the commensal species may show great structural adaptation consistent with its habits, as in the remoras that ride attached to sharks and other fishes. Remo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carapus Acus
''Carapus acus'' is a species of bony fish in the family Carapidae, the pearlfishes, and is native to the Mediterranean Sea and the Atlantic Ocean. It lives as a commensal in association with a sea cucumber, spending the day inside its host and emerging at night to feed. Description ''Carapus acus'' is a laterally-compressed, elongated fish growing to a length of about . The head measures about one eighth of the total length and there are 84 to 92 vertebrae, which gives the fish great flexibility. The continuous dorsal fin and the anal fin run the whole length of the body. There is no caudal fin and the tail ends with a point. The gut loops back and the anus is located just behind the head, in front of the pectoral fins. This fish is translucent, with a number of silvery or reddish-gold iridescent spots on the operculum and the thoracic region. The peritoneum lining the body cavity is an opaque silvery colour. Distribution ''Carapus acus'' is native to the Mediterranean Sea and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parastichopus Regalis
''Parastichopus regalis'', also known as the royal sea cucumber, is a species of sea cucumber in the family Stichopodidae. Description ''Parastichopus regalis'' grows to a length of about . The body is soft and somewhat flattened, and a clearly incised lateral fold with large papillae separates the dorsal surface from the ventral surface. The dorsal surface is mottled brown, and the ventral surface is rather paler, with a darker longitudinal streak in the centre. The bony sclerites that strengthen the integument include tables, terminal plates and perforated plates; the sclerites in the tentacles that surround the mouth include elongated, branched, perforated and arched rods. Distribution and habitat ''Parastichopus regalis'' is found in the Mediterranean Sea, along the coasts of Africa in the eastern Atlantic Ocean, and in the tropical and subtropical western Atlantic Ocean, including the Gulf of Mexico. It is typically found on sand or other soft substrates, at depths down to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (" holometaboly"), incomplete metamorphosis ("hemimetaboly"), or no metamorphosis (" ametaboly"). Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. Generally organisms with a larva stage undergo metamorphosis, and during metamorphosis the organism loses larval characteristics. References to "metamorphosis" in mammals are imprecise and only colloquial, but historically idealist ideas of transformation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as ''Chlorella,'' ''Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and autotrophic (they generate food internally) and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the ''Charophyta'', a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. No definition of algae is generally accepted. One definition is that algae "have chlorophyll ''a'' as their primary photosynthetic pigment and lack a sterile covering of cells around thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The larva's appearance is generally very different from the adult form (''e.g.'' caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the larval stage will consume food to fuel their transition into the adult form. In some organisms like polychaetes and barnacles, adults are immobil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg (biology)
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the animal hatches. Most arthropods such as insects, vertebrates (excluding live-bearing mammals), and mollusks lay eggs, although some, such as scorpions, do not. Reptile eggs, bird eggs, and monotreme eggs are laid out of water and are surrounded by a protective shell, either flexible or inflexible. Eggs laid on land or in nests are usually kept within a warm and favorable temperature range while the embryo grows. When the embryo is adequately developed it hatches, i.e., breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark and was in size. Whale shark eggs typically hatch within the mother. At and up to , the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamete
A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete—called an ovum— and a male produces the smaller type—called a sperm. Sperm cells or spermatozoa are small and motile due to the flagellum, a tail-shaped structure that allows the cell to propel and move. In contrast, each egg cell or ovum is relatively large and non-motile. In short a gamete is an egg cell (female gamete) or a sperm (male gamete). In animals, ova mature in the ovaries of females and sperm develop in the testes of males. During fertilization, a spermatozoon and ovum unite to form a new diploid organism. Gametes carry half the genetic information of an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Full Moon
The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective. This occurs when Earth is located between the Sun and the Moon (when the ecliptic coordinate system, ecliptic longitudes of the Sun and Moon opposition (astronomy), differ by 180°). This means that the lunar hemisphere facing Earth—the near side of the Moon, near side—is completely sunlit and appears as an approximately circular disk. The full moon occurs roughly once a month. The time interval between a full moon and the next repetition of the same phase, a Lunar month#Synodic month, synodic month, averages about 29.53 days. Therefore, in those lunar calendars in which each month begins on the day of the new moon, the full moon falls on either the 14th or 15th day of the lunar month. Because a calendar month consists of a Natural number, whole number of days, a month in a lunar calendar may be either 29 or 30 days long. Characteristics A full moon is often thought of as an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
