|
Deto Echinata
''Deto echinata'', the horned isopod, is a species of air-breathing isopod, or woodlouse, in the family Detonidae. It inhabits seashores in southern Africa and on some oceanic islands. Description ''Deto echinata'' is distinguished by a pair of long curved "horns" situated on the back of each segment of the thorax. These horns are substantially longer in males than in females. Horn length in males has been found to be correlated with body condition, and it is hypothesized that this sexual dimorphism acts as an indicator of overall fitness and is the result of sexual selection. Colouration is dark brown on the back, lighter brown in patches, underneath and on the extremities. Males have an average length of 30 mm, females of 22 mm, making the species one of the largest in the suborder. Distribution The species occurs on the coast of southern Africa, having been recorded in Namibia, South Africa and Mozambique. It can also be found on ÃŽle Amsterdam and ÃŽle Saint-Paul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fitness (biology)
Fitness (often denoted w or ω in population genetics models) is the quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals of the specified genotype or phenotype. Fitness can be defined either with respect to a genotype or to a phenotype in a given environment or time. The fitness of a genotype is manifested through its phenotype, which is also affected by the developmental environment. The fitness of a given phenotype can also be different in different selective environments. With asexual reproduction, it is sufficient to assign fitnesses to genotypes. With sexual reproduction, recombination scrambles alleles into different genotypes every generation; in this case, fitness values can be assigned to alleles by averaging over possible genetic backgrounds. Natural selection tends to make alleles with higher fitness more common over time, resulting in Dar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodlice
A woodlouse (plural woodlice) is an isopod crustacean from the polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their name from often being found in old wood. The first woodlice were marine isopods which are presumed to have colonised land in the Carboniferous, though the oldest known fossils are from the Cretaceous period. They have many common names and although often referred to as terrestrial isopods, some species live semiterrestrially or have recolonised aquatic environments. Woodlice in the families Armadillidae, Armadillidiidae, Eubelidae, Tylidae and some other genera can roll up into a roughly spherical shape (conglobate) as a defensive mechanism; others have partial rolling ability, but most cannot conglobate at all. Woodlice have a basic morphology of a segmented, dorso-ventrally flattened body with seven pairs of jointed legs, specialised appendages for respiration and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligia Dilatata
''Ligia dilatata'' is a woodlouse in the family Ligiidae. Identification It has a finely granular surface and a body that is slightly convex, as well as eyes that are large and convex. It has relatively small uropods. It can be differentiated from '' L. glabrata'', with which it shares some range, by its antennae. The antennae of ''L. dilatata'' are longer, reaching the end of its thorax. Habits ''Ligia dilatata'' feeds extensively on dislodged '' Ecklonia maxima'' and ''Laminaria pallida ''Laminaria pallida'', the split-fan kelp, is a species of large brown seaweed of the class Phaeophyceae found from Danger Point on the south coast of South Africa to Port Nolloth, Tristan da Cunha and Gough islands in the Atlantic and ÃŽle Saint ...'' that wash up on shore. They gather in large numbers on these kelp. The species lives about 2 years. Females start reproducing at 12 months but, unlike males, probably do not survive to breed twice. The brood period is 5 to 6 weeks. Growth i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intertidal Zone
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species of life, such as seastars, sea urchins, and many species of coral with regional differences in biodiversity. Sometimes it is referred to as the '' littoral zone'' or '' seashore'', although those can be defined as a wider region. The well-known area also includes steep rocky cliffs, sandy beaches, bogs or wetlands (e.g., vast mudflats). The area can be a narrow strip, as in Pacific islands that have only a narrow tidal range, or can include many meters of shoreline where shallow beach slopes interact with high tidal excursion. The peritidal zone is similar but somewhat wider, extending from above the highest tide level to below the lowest. Organisms in the intertidal zone are adapted to an environment of harsh extremes, living in w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ÃŽle Saint-Paul
Île Saint-Paul (Saint Paul Island) is an island forming part of the French Southern and Antarctic Lands (''Terres australes et antarctiques françaises'', TAAF) in the Indian Ocean, with an area of . The island is located about south of the larger Île Amsterdam (), northeast of the Kerguelen Islands, and southeast of Réunion. It is an important breeding site for seabirds. A scientific research cabin on the island is used for scientific or ecological short campaigns, but there is no permanent population. It is under the authority of a senior administrator on Réunion. Geography Île Saint-Paul is a volcanic island with triangular in shape that measures no more than at its widest point. It is the top of an active volcano; the volcano last erupted in 1793 (from its SW Flank), and is rocky with steep cliffs on the east side. The thin stretch of rock that used to close off the crater collapsed in 1780, admitting the sea through a channel; the entrance is only a few meter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ÃŽle Amsterdam
Île Amsterdam (), also known as Amsterdam Island and New Amsterdam (''Nouvelle-Amsterdam''), is an island of the French Southern and Antarctic Lands in the southern Indian Ocean that together with neighbouring Île Saint-Paul to the south forms one of the five districts of the territory. The island is roughly equidistant to the land masses of Madagascar, Australia, and Antarctica – as well as the British Indian Ocean Territory and the Cocos (Keeling) Islands (about from each). The research station at Martin-de-Viviès, first called ''Camp Heurtin'' and then ''La Roche Godon'', is the only settlement on the island and is the seasonal home to about thirty researchers and staff studying biology, meteorology, and geomagnetics. History The first person known to have sighted the island was the Spanish explorer Juan Sebastián de Elcano, on 18 March 1522, during his circumnavigation of the world. Elcano did not give the island a name. On 17 June 1633, Dutch mariner Anthonie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mozambique
Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Africa to the southwest. The sovereign state is separated from the Comoros, Mayotte and Madagascar by the Mozambique Channel to the east. The capital and largest city is Maputo. Notably Northern Mozambique lies within the monsoon trade winds of the Indian Ocean and is frequentely affected by disruptive weather. Between the 7th and 11th centuries, a series of Swahili port towns developed on that area, which contributed to the development of a distinct Swahili culture and language. In the late medieval period, these towns were frequented by traders from Somalia, Ethiopia, Egypt, Arabia, Persia, and India. The voyage of Vasco da Gama in 1498 marked the arr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini. It also completely enclaves the country Lesotho. It is the southernmost country on the mainland of the Old World, and the second-most populous country located entirely south of the equator, after Tanzania. South Africa is a biodiversity hotspot, with unique biomes, plant and animal life. With over 60 million people, the country is the world's 24th-most populous nation and covers an area of . South Africa has three capital cities, with the executive, judicial and legislative branches of government based in Pretoria, Bloemfontein, and Cape Town respectively. The largest city is Johannesburg. About 80% of the population are Black Sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and east. Although it does not border Zimbabwe, less than 200 metres (660 feet) of the Botswanan right bank of the Zambezi River separates the two countries. Namibia gained independence from South Africa on 21 March 1990, following the Namibian War of Independence. Its capital and largest city is Windhoek. Namibia is a member state of the United Nations (UN), the Southern African Development Community (SADC), the African Union (AU) and the Commonwealth of Nations. The driest country in sub-Saharan Africa, Namibia has been inhabited since pre-historic times by the San, Damara and Nama people. Around the 14th century, immigrating Bantu peoples arrived as part of the Bantu expansion. Since then, the Bantu groups, the largest being the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Selection
Sexual selection is a mode of natural selection in which members of one biological sex choose mates of the other sex to mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have greater reproductive success than others within a population, for example because they are more attractive or prefer more attractive partners to produce offspring. Successful males benefit from frequent mating and monopolizing access to one or more fertile females. Females can maximise the return on the energy they invest in reproduction by selecting and mating with the best males. The concept was first articulated by Charles Darwin who wrote of a "second agency" other than natural selection, in which competition between mate candidates could lead to speciation. The theory was given a mathematical basis by Ronald Fisher in the early 20th century. Sexual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_at_St_Paul_Island.jpg "Click for more on -> ÃŽle Saint-Paul")
