|
Leptopsammia Pruvoti
''Leptopsammia pruvoti'', the sunset cup coral, is a solitary stony coral in the family Dendrophylliidae. It is an azooxanthellate species, meaning its tissues do not contain the symbiotic unicellular algae (zooxanthellae) of the genus ''Symbiodinium'', as do most corals. It is native to the Mediterranean Sea. The species was described by Henri de Lacaze-Duthiers in 1897 and named to honor the French marine biologist Georges Pruvot. Description ''Leptopsammia pruvoti'' is a solitary stony coral and superficially resembles a sea anemone. The polyp sits in a calcareous cup, wider at the base than the top, which varies in shape from cylindrical and short to conical and long. It grows to a height of about and a diameter of . The polyp is yellow or orange with about ninety-six long, translucent yellow tentacles. It can retract back into the skeletal cup, so that the tentacles become barely visible. This species can be confused with another yellow or orange cup coral, ''Balanophylli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henri De Lacaze-Duthiers
Félix Joseph Henri de Lacaze-Duthiers (15 May 1821 – 21 July 1901) was a French biologist, anatomist and zoologist born in Montpezat, Lot-et-Garonne, Montpezat in the department of Lot-et-Garonne. He was a leading authority in the field of malacology. He studied medicine in Paris, and worked at Necker Hospital under Armand Trousseau (1801–1867). Later on, with Jules Haime (1824–1856), he travelled to the Balearic Islands to study marine life. In 1854 he returned to Paris as an assistant to Henri Milne-Edwards (1800–1885), and soon afterwards became a professor of zoology in Université Lille Nord de France, Lille. In 1865 he succeeded Achille Valenciennes (1794–1865) as chair of ''histoire naturelle des mollusques, des vers et des zoophytes'' at the National Museum of Natural History, France, and in 1868 became a professor at the University of Paris. In 1871 he was elected to French Academy of Sciences in the department of anatomy and zoology. Lacaze-Duthiers is remem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tentacle
In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work mainly like muscular hydrostats. Most forms of tentacles are used for grasping and feeding. Many are sensory organs, variously receptive to touch, vision, or to the smell or taste of particular foods or threats. Examples of such tentacles are the eyestalks of various kinds of snails. Some kinds of tentacles have both sensory and manipulatory functions. A tentacle is similar to a cirrus, but a cirrus is an organ that usually lacks the tentacle's strength, size, flexibility, or sensitivity. A nautilus has cirri, but a squid has tentacles. Invertebrates Molluscs Many molluscs have tentacles of one form or another. The most familiar are those of the pulmonate land snails, which usually have two sets of tentacles on the head: when extended ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generation Time
In population biology and demography, generation time is the average time between two consecutive generations in the lineages of a population. In human populations, generation time typically ranges from 22 to 33 years. Historians sometimes use this to date events, by converting generations into years to obtain rough estimates of time. Definitions and corresponding formulas The existing definitions of generation time fall into two categories: those that treat generation time as a renewal time of the population, and those that focus on the distance between individuals of one generation and the next. Below are the three most commonly used definitions: The time it takes for the population to grow by a factor of its net reproductive rate The net reproductive rate \textstyle R_0 is the number of offspring an individual is expected to produce during its lifetime (a net reproductive rate of 1 means that the population is at its demographic equilibrium). This definition envisions the ... [...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] |
Planula
A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores. Some groups of Nemerteans also produce larvae that are very similar to the planula, which are called planuliform larva. Development The planula forms either from the fertilized egg of a medusa, as is the case in scyphozoans and some hydrozoans, or from a polyp, as in the case of anthozoans. Depending on the species, the planula either metamorphoses directly into a free-swimming, miniature version of the mobile adult form, or navigates through the water until it reaches a hard substrate (many may prefer specific substrates) where it anchors and grows into a polyp. The miniature-adult types include many open-ocean scyphozoans. The attaching types include all anthozoans with a planula stage, many coastal scyphozoans, and some hydrozoans. Feeding and locomotion The planulae of the subphylum Medusozoa have no mouth, and no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitism
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, 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 paras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megatrema Anglicum
''Adna'' is a genus of acorn barnacles that grows in association with or semi-parasitically on corals and octocorals. Its only species is ''Adna anglica''. It is found in the intertidal zone on the coasts of northwestern Europe and in the Mediterranean Sea. Description ''Adna anglicum'' has a pink conical shell on a cup-shaped base and can grow to a diameter of up to . There are longitudinal striations on the shell and the operculum, the lid to the opening through which the barnacle's feeding parts protrude, is depressed, so that the structure is vase-shaped. Another barnacle, '' Verruca stroemia'', is sometimes found at the foot of the coral's calcified cup, but ''M. anglicum'' seems to be the only barnacle species adapted to live in close proximity to the coral's tentacles. Ecology In British waters, where it is at the northern limit of its range, ''Adna anglicum'' is found in association with the solitary cup coral ''Caryophyllia smithii'', and in the Mediterranean it is of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astroides
''Astroides'' is a genus of stony cup corals in the family Dendrophylliidae. It is monotypic and the only species is ''Astroides calycularis'', which is endemic to the western Mediterranean Sea. The species was first described in 1766 by the German naturalist Peter Simon Pallas. Description ''Astroides calycularis'' is a colonial coral, consisting of a group of polyps, each of which sits in a stony cup known as a calyx. The colonies are in diameter and high and each polyp is about in diameter. The polyps are yellow or orange, each with a fringe of about thirty very short tentacles surrounding a slit-shaped mouth. The colony grows by asexual reproduction, new polyps budding off existing polyps and secreting their own calices. Deep-water colonies are bush-shaped, the calices are circular and budding occurs at various heights on the calyx walls. Shallow-water colonies tend to be ellipsoid in shape, the calyces are polygonal and budding occurs in the centre of the colony as wel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colony (biology)
In biology, a colony is composed of two or more conspecific individuals living in close association with, or connected to, one another. This association is usually for mutual benefit such as stronger defense or the ability to attack bigger prey. Colonies can form in various shapes and ways depending on the organism involved. For instance, the bacterial colony is a cluster of identical cells (clones). These colonies often form and grow on the surface of (or within) a solid medium, usually derived from a single parent cell. Colonies, in the context of development, may be composed of two or more unitary (or solitary) organisms or be modular organisms. Unitary organisms have determinate development (set life stages) from zygote to adult form and individuals or groups of individuals (colonies) are visually distinct. Modular organisms have indeterminate growth forms (life stages not set) through repeated iteration of genetically identical modules (or individuals), and it can be diffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adriatic Sea
The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to the northwest and the Po Valley. The countries with coasts on the Adriatic are Albania, Bosnia and Herzegovina, Croatia, Italy, Montenegro, and Slovenia. The Adriatic contains more than 1,300 islands, mostly located along the Croatian part of its eastern coast. It is divided into three basins, the northern being the shallowest and the southern being the deepest, with a maximum depth of . The Otranto Sill, an underwater ridge, is located at the border between the Adriatic and Ionian Seas. The prevailing currents flow counterclockwise from the Strait of Otranto, along the eastern coast and back to the strait along the western (Italian) coast. Tidal movements in the Adriatic are slight, although larger amplitudes are known to occur occasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balanophyllia Regia
''Balanophyllia'' is a genus of solitary corals in the order of stony corals. Subgenera The genus includes two subgenera with species as follows: *'' Balanophyllia (Balanophyllia)'' Wood, 1844 ** '' Balanophyllia bairdiana'' Milne Edwards & Haime, 1848 ** ''Balanophyllia bayeri'' Cairns, 1979 ** ''Balanophyllia bonaespei'' van der Horst, 1938 ** ''Balanophyllia capensis'' Verrill, 1865 ** ''Balanophyllia cedrosensis'' Durham, 1947 ** '' Balanophyllia cellulosa'' Duncan, 1873 ** '' Balanophyllia chnous'' Squires, 1962 ** '' Balanophyllia corniculans'' (Alcock, 1902) ** '' Balanophyllia cornu'' Moseley, 1881 ** '' Balanophyllia crassiseptum'' Cairns & Zibrowius, 1997 ** ''Balanophyllia crassitheca'' Cairns, 1995 ** ''Balanophyllia cumingii'' Milne Edwards & Haime, 1848 ** '' Balanophyllia cyathoides'' ( Pourtalès, 1871) ** ''Balanophyllia dentata'' Tenison Woods, 1879 ** ''Balanophyllia desmophyllioides'' Vaughan, 1907 ** ''Balanophyllia diademata'' van der Horst, 1927 ** ''Balano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyp (zoology)
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are roughly cylindrical in shape and elongated at the axis of the vase-shaped body. In solitary polyps, the aboral (opposite to oral) end is attached to the substrate by means of a disc-like holdfast called a pedal disc, while in colonies of polyps it is connected to other polyps, either directly or indirectly. The oral end contains the mouth, and is surrounded by a circlet of tentacles. Classes In the class Anthozoa, comprising the sea anemones and corals, the individual is always a polyp; in the class Hydrozoa, however, the individual may be either a polyp or a medusa, with most species undergoing a life cycle with both a polyp stage and a medusa stage. In class Scyphozoa, the medusa stage is dominant, and the polyp stage may or may not be present, depending on the family. In those scyphozoans that have the larval planula metamorphose into a polyp, the polyp, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
