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Amplexus
Amplexus (Latin "embrace") is a type of mating behavior exhibited by some externally fertilizing species (chiefly amphibians and horseshoe crabs) in which a male grasps a female with his front legs as part of the mating process, and at the same time or with some time delay, he fertilizes the eggs, as they are released from the female's body. In amphibians, females may be grasped by the head, waist, or armpits, and the type of amplexus is characteristic of some taxonomic groups. Amplexus involves direct contact between male and female, distinguished from other forms of external fertilization, such as broadcast spawning, where sperm and eggs are freely shed into water without direct contact by individuals. In order for amplexus to be initiated, male frogs must first find a mate by attracting one through calls, typically in the evening. Once a male has successfully attracted a mate, the process of amplexus begins, while the unsuccessful males are forced to continue their search fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplexus Bufo Bufo 2010-03-29
Amplexus (Latin "embrace") is a type of mating behavior exhibited by some externally fertilizing species (chiefly amphibians and horseshoe crabs) in which a male grasps a female with his front legs as part of the mating process, and at the same time or with some time delay, he fertilizes the eggs, as they are released from the female's body. In amphibians, females may be grasped by the head, waist, or armpits, and the type of amplexus is characteristic of some taxonomic groups. Amplexus involves direct contact between male and female, distinguished from other forms of external fertilization, such as broadcast spawning, where sperm and eggs are freely shed into water without direct contact by individuals. In order for amplexus to be initiated, male frogs must first find a mate by attracting one through calls, typically in the evening. Once a male has successfully attracted a mate, the process of amplexus begins, while the unsuccessful males are forced to continue their search for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibian
Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial animal, terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Thus amphibians typically start out as larvae living in water, but some species have developed behavioural adaptations to bypass this. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators; in re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frog
A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is known from the Early Triassic of Madagascar, but molecular clock, molecular clock dating suggests their split from other amphibians may extend further back to the Permian, 265 Myr, million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest. Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from Taxonomy (biology), taxonomy or evolutionary history. An adult frog has a stout body, protruding eyes, anteriorly-attached tongue, limb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascaphus
The tailed frogs are two species of frogs in the genus ''Ascaphus'', the only taxon in the family Ascaphidae . The "tail" in the name is actually an extension of the male cloaca. The tail is one of two distinctive anatomical features adapting the species to life in fast-flowing streams. These are the only North American frog species that reproduce by internal fertilization. They are among the most primitive known families of frogs. Its scientific name means 'without a spade', from the privative prefix '' a-'' and the Ancient Greek ' (, 'spade, shovel'), referring to the metatarsal spade, which these frogs do not have. Taxonomy Until 2001, the genus was believed to be monotypic, the single species being the tailed frog (''Ascaphus truei'' Stejneger, 1899). However, in that year, Nielson, Lohman, and Sullivan published evidence that promoted the Rocky Mountain tailed frog (''Ascaphus montanus'') from a subspecies to its own species. Since then, the former species has been formall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sooglossidae
Sooglossidae, the Seychelles frogs or Seychelles Island frogs, are a family of frogs found on the Seychelles Islands. Until recently, this family was believed to include the genera ''Sechellophryne'', '' Nesomantis'' and '' Sooglossus'', but following a major revision of amphibians in 2006, the genus ''Nesomantis'' was named a junior synonym of ''Sooglossus''. Their closest relatives are the purple frogs ( Nasikabatrachidae) of India. Description All Sooglossidae species are relatively small terrestrial frogs, about in length, hiding under fallen leaves or in rock crevices. They are unusual for the neobatrachials, in that they undertake inguinal amplexus, a primitive version of amplexus. They lay their eggs on moist ground, rather than in water. Several species lack tadpoles, with the eggs hatching directly into froglets. The tadpoles of '' S. sechellensis'' are carried, abnormally, on the backs of the female frogs until metamorphosis. There is no fossil record for the family. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertilize
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Processes such as insemination or pollination which happen before the fusion of gametes are also sometimes informally called fertilisation. The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation. History In Antiquity, Aristotle conceived the formation of new individuals through fusion of male and female fluids, with form and function emerging gradually, in a mode called by him as epigenetic. In 1784, Spallanzani established the need of interaction between the female's ovum and male's sperm to form a zygote in frogs. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strongylopus Grayii In Amplexus
''Strongylopus'' ('strongylos'=round, 'pus'=foot) is a genus of pyxicephalid frogs native to Africa. They are found in the area from southwestern South Africa and Namibia to northern Tanzania. Their common name is stream frogs. Description ''Strongylopus'' are small to medium-sized frogs: adult snout–vent lengths are typically in the range of . Species within this genus may be found at altitudes from sea level up to 3250 m in elevation. They generally occur in riparian habitats, including fynbos heath, grassland, montane flooded grassland, savanna and forest edge. Some species occur in more specific habitats, such as '' Strongylopus kilimanjaro'' in alpine moorland near cold water streams. Species These species belong to this genus: * '' Strongylopus bonaespei'' (Dubois, 1981) – Banded stream frog * '' Strongylopus fasciatus'' (Smith, 1849) – Striped stream frog * '' Strongylopus fuelleborni'' (Nieden, 1911) – Fuelleborn's stream frog * ''Strongylopus grayii'' (Smi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mertensophryne
''Mertensophryne'' is a genus of true toads (family Bufonidae). They are found in eastern and southern Democratic Republic of Congo to Kenya, Tanzania, Malawi, southeastern Zimbabwe, and adjacent Mozambique. Their common names include snouted frogs, Chirinda forest toads, and forest toads. The genus is named for Robert Mertens, German zoologist and herpetologist. Taxonomy ''Mertensophryne'', as currently understood, consist of the former ''"Bufo" taitanus'' group and the genera ''Mertensophryne'' (as formerly defined) and ''Stephopaedes''. The latter is monophyletic and still recognized as a subgenus. The closest relatives of ''Mertensophryne'' remain uncertain but probably include ''Poyntonophrynus'', '' Vandijkophrynus'', and ''Capensibufo''. Description ''Mertensophryne'' lack tympanum and columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intromittent Organ
An intromittent organ is any external organ of a male organism that is specialized to deliver sperm during copulation. Intromittent organs are found most often in terrestrial species, as most non-mammalian aquatic species fertilize their eggs externally, although there are exceptions. For many species in the animal kingdom, the male intromittent organ is a hallmark characteristic of internal fertilization. Species with intromittent organs Invertebrates Molluscs Male cephalopods have a specialized arm, the hectocotylus, which is inserted into the female's mantle cavity to deliver a spermatophore during copulation. In some species, the hectocotylus breaks off inside the female's mantle cavity; in others, it can be used repeatedly to copulate with different females. Arachnids In spiders the intromittent organs are the male pedipalps, even though these are not primarily sexual organs, but serve as indirect mating organs; in the male the pedipalps have hollow, clubbed tips, oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nectophrynoides
''Nectophrynoides'' is a genus of true toads, family Bufonidae. They are endemic to Eastern Arc forests and wetlands in Tanzania,Channing and Howell. (2006). ''Amphibians of East Africa.'' Pp. 104–117. and all except '' N. tornieri'' are threatened. Species of the genus are ovoviviparous: fertilization is internal, and the females give birth to fully developed, small toadlets. Together with the West Africa ''Nimbaphrynoides'' (which was included in ''Nectophrynoides'' in the past) and ''Limnonectes larvaepartus'', they are the only frogs/toads in the world that do not lay eggs.Wells (2007). ''The Ecology and Behavior of Amphibians.'' Pp. 486–487. The Ethiopian ''Altiphrynoides ''Altiphrynoides'' is a genus of toads, commonly referred to as Ethiopian toads. They are restricted to highlands of south-central Ethiopia in the Arussi, Bale and Sidamo Provinces. Both species are threatened by habitat loss.Stuart ''et al.'' ...'' (includes ''Spinophrynoides''), which lay eggs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newt
A newt is a salamander in the subfamily Pleurodelinae. The terrestrial juvenile phase is called an eft. Unlike other members of the family Salamandridae, newts are semiaquatic, alternating between aquatic and terrestrial habitats. Not all aquatic salamanders are considered newts, however. More than 100 known species of newts are found in North America, Europe, North Africa and Asia. Newts metamorphose through three distinct developmental life stages: aquatic larva, terrestrial juvenile (eft), and adult. Adult newts have lizard-like bodies and return to the water every year to breed, otherwise living in humid, cover-rich land habitats. Newts are threatened by habitat loss, fragmentation and pollution. Several species are endangered, and at least one species, the Yunnan lake newt, has become extinct recently. Etymology The Old English name of the animal was , (of unknown origin), resulting in Middle English ; this word was transformed irregularly into , , or . The initial "n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eleutherodactylus
''Eleutherodactylus'' is a genus of frogs in the family Eleutherodactylidae.Hedges, S. B., W. E. Duellman, and M. P. Heinicke . 2008. New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and conservation. Zootaxa 1737: 1-182. Many of the 200 species of the genus are commonly known as "rain frogs" or "robber frogs", due to their sharp, high-pitched, insect-like calls. The best-known species is the common coquí (''E. coqui''), which is both a national symbol of Puerto Rico and a notorious invasive species in Hawaii. Two ''Eleutherodactylus'' species, '' E. limbatus'' and '' E. iberia'', are among the smallest known frogs, measuring only 8.5 mm in length (only slightly larger than ''Paedophryne amauensis'', which measures around 7.7 mm). Etymology The name "Eleutherodactylus" is derived from the Greek words for ‘free-toed’, composed of the Ancient Greek ' (, ‘free, unbound’) and ' (, ‘finger, toe’). Most sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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