Instruct: Given a question, retrieve passages that answer the question.
Query: How many animals are hermaphrodites?
A rough estimate of the number of hermaphroditic animal species is 65,000. Since the estimated total number of animal species is 8.6 million, the percentage of animal species that are hermaphroditic is about 0.7%. Arthropods are the phylum with the largest number of species. Most hermaphroditic species exhibit some degree of self-fertilization. The distribution of self-fertilization rates among animals is similar to that of plants, suggesting that similar processes are operating to direct the evolution of selfing in animals and plants.
While comparing between various classes of animals, a different unit is used, body length per second for organisms. The fastest organism on earth, relative to body length, is the South Californian mite "Paratarsotomus macropalpis", which has a speed of 322 body lengths per second. The equivalent speed for a human running as fast as this mite would be . This is far in excess of the previous record holder, the Australian tiger beetle, "Cicindela eburneola", the fastest insect in the world relative to body size, which has been recorded at or 171 body lengths per second. The cheetah, the fastest land mammal, scores at only 16 body lengths per second while Anna's hummingbird has the highest known length-specific velocity attained by any vertebrate
They are mostly ambush predators, but a few ground-dwelling species are found actively pursuing their prey. They normally live for about a year. In cooler climates, the adults lay eggs in autumn then die. The eggs are protected by their hard capsules and hatch in the spring. Females sometimes practice sexual cannibalism, eating their mates after copulation. Occasionally, the females decapitate the males just before or during mating. Over 2,400 species of mantis in about 430 genera are recognized.
Gestation lasts from 65 to 83 days and normally results in the birth of a litter of three to six pups, although larger litters of up to 10 have been reported. The young are born blind and helpless and initially weigh . The eyes open after 14 to 19 days and the pups first emerge from the nativity den shortly thereafter. The young are weaned at around four weeks and reach sexual maturity at one year. They can live for up to 10 years in captivity.
Toxorhynchites, also called elephant mosquito or mosquito eater, is a genus of diurnal and often relatively colorful mosquitoes, found worldwide between about 35° north and 35° south. It includes the largest known species of mosquito, at up to in length and in wingspan. It is among the many kinds of mosquito that do not consume blood. The adults subsist on carbohydrate-rich materials, such as honeydew, or saps and juices from damaged plants, refuse, fruit, and nectar.
The elephants comprise three living species and are the largest living land animals.Sirenia is an order of fully aquatic, herbivorous mammals that inhabit rivers, estuaries, coastal marine waters, swamps, and marine wetlands. All four species are endangered.The treeshrews are small mammals native to the tropical forests of Southeast Asia. Although called treeshrews, they are not true shrews and are not all arboreal.The two species of colugos make up the order Dermoptera. They are arboreal gliding mammals found in Southeast Asia.The order Primates contains humans and their closest relatives: lemurs, lorisoids, monkeys, and apes.Rodents make up the largest order of mammals, with over 40 percent of mammalian species. They have two incisors in the upper and lower jaw which grow continually and must be keep short by gnawing. Most rodents are small though the capybara can weigh up to 45 kg (100 lb).
Black wildebeest act as hosts to a number of external and internal parasites. A study of the animal in Karroid Mountainveld (Eastern Cape Province, South Africa) revealed the presence of all the larval stages of the nasal bot flies "Oestrus variolosus" and "Gedoelstia hässleri". The first instar larvae of "G. hässleri" were found in large numbers on the dura mater of wildebeest calves, specially between June and August, and these later migrated to the nasal passages. Repeated outbreaks of mange (scab) have led to large-scale extinctions. The first study of the protozoa in blue and black wildebeest showed the presence of 23 protozoan species in the rumen, with "Diplodinium bubalidis" and "Ostracodinium damaliscus" common in all the animals.
"L. minor" is a solitary species and like most other praying mantises will only come together to mate. Mating times for this species are highly dependent upon weather conditions and prey availability. Typically females are most likely to accept a mate and have a successful clutch two weeks after their last molt.
The fact that females appear to have outnumbered males two to one suggests that, as with modern animals with size-related sexual dimorphism, such as sea lions and other pinnipeds, "Pteranodon" might have been polygynous, with a few males competing for association with groups consisting of large numbers of females. Similar to modern pinnipeds, "Pteranodon" may have competed to establish territory on rocky, offshore rookeries, with the largest, and largest-crested, males gaining the most territory and having more success mating with females. The crests of male "Pteranodon" would not have been used in competition, but rather as "visual dominance-rank symbols", with display rituals taking the place of physical competition with other males. If this hypothesis is correct, it also is likely that male "Pteranodon" played little to no part in rearing the young; such a behavior is not found in the males of modern polygynous animals who father many offspring at the same time.
The family's common name is derived from a length of "free" tail, projecting beyond the end of the uropatagium—the membrane that connects the base of the tail to the hind legs. The tail is usually best seen when resting. A special ring of cartilage slides up or down the tail vertebrae by muscular action to stretch or retract the tail membrane. This gives many species a degree of fine tuning in their flight maneuvers to rival their day-flying ecological equivalents, such as swifts, swallows, and martins. As a result, these animals include the fastest-flying of all bat species among their number. The dental formula of free-tailed bats varies between species:
During the 15th and 16th centuries, travellers to Africa provided further descriptions of the species. Leo Africanus repeated some of the old concepts on the hyena, with the addition of describing its legs and feet as similar to those of men. In 1551, Swiss naturalist Conrad Gesner rejected the belief of the hyena's hermaphroditism, and theorised that it originated from confusion over an androgynous fish bearing the same name. He adds three other animals within the category of hyenas, including an Ethiopian quadruped named "Crocotta", which was thought to be a hybrid between a hyena and a lioness. Sir Thomas Browne also argued against the hyena's supposed hermaphroditism, stating that all animals follow their own "Law of Coition", and that a hermaphrodite would transgress this. Sir Walter Raleigh, in an attempt to rationalise how Noah's Ark could have fitted all extant species of animal, wrote that hyenas were hybrids between foxes and wolves which originated after the Great Flood. References to the spotted hyena's vocalisations are referenced in numerous contemporary examples of English literature, including Shakespeare's "As You Like It" and George Chapman's "Eastward Ho". John Milton, in his "Samson Agonistes", compares the species to Delila.
Merian was one of the first naturalists to observe insects directly. Merian collected and observed live insects and created detailed drawings. In her time insects still had a reputation as "beasts of the devil" and the process of metamorphosis was largely unknown. While a handful of scholars had published empirical information on the insect, moth and butterfly life cycle, the widespread contemporary believe was that they were "born of mud" by spontaneous generation. Merian documented evidence to the contrary and described the life cycles of 186 insect species.
The yellow-billed oxpecker eats insects and ticks. Both the English and scientific names arise from this species' habit of perching on large wild and domesticated mammals such as cattle and eating arthropod parasites. It will also perch on antelopes such as wildebeest. In a day an adult will take more than 100 engorged female "Boophilus decoloratus" ticks or 13,000 larvae.
Besides the horse, there are six other species of genus "Equus" in the Equidae family. These are the ass or donkey, "Equus asinus"; the mountain zebra, "Equus zebra"; plains zebra, "Equus quagga"; Grévy's zebra, "Equus grevyi"; the kiang, "Equus kiang"; and the onager, "Equus hemionus".
In most subsequent forms, many of these early ribs have been lost, and in living amphibians and reptiles, there is great variation in rib structure and number. For example, turtles have only eight pairs of ribs, which are developed into a bony or cartilaginous carapace and plastron, while snakes have numerous ribs running along the full length of their trunk. Frogs typically have no ribs, aside from a sacral pair, which form part of the pelvis.
Adult "Pteranodon" specimens may be divided into two distinct size classes, small and large, with the large size class being about one and a half times larger than the small class, and the small class being twice as common as the large class. Both size classes lived alongside each other, and while researchers had previously suggested that they represent different species, Christopher Bennett showed that the differences between them are consistent with the concept that they represent females and males, and that "Pteranodon" species were sexually dimorphic. Skulls from the larger size class preserve large, upward and backward pointing crests, while the crests of the smaller size class are small and triangular. Some larger skulls also show evidence of a second crest that extended long and low, toward the tip of the beak, which is not seen in smaller specimens.
A fully-grown "Smilodon" weighed approximately and had a short tail, powerful legs, and a large head. The cats have two huge canine teeth, about long, that are used to kill prey by suffocation. The jaws could open to about 120 degrees in order to use these fangs to deadly effect. They would die out due to climate change.
Mosquitos belong to the biological Order of Diptera (which includes all two-winged insects), suborder Nematocera, family Culicidea. There are >3,500 different mosquito species with the Aedes and Culex genera being common in North America. It is assumed that any species of mosquito that causes an ordinary mosquito bite reaction in humans is capable of causing MBA. In addition to mosquitoes, the Diptera order includes numerous other types of biting insects such as midges (e.g. sand flies) and gnats. Bites by the latter insects or possibly some other insects may cause reactions that are mechanistically and clinically similar to those seen with mosquito bites.
On occasion, the bone of a fossilised predator is preserved well enough to retain recognizable proteins that belong to the species it consumed when alive. Stable isotope analysis of these proteins has shown that "Smilodon" preyed mainly on bison and horses, and occasionally ground sloths and mammoths, while "Homotherium" often preyed on young mammoths and other grazers such as pronghorn antelope and bighorn sheep when mammoths were not available.
Females of most mammal species advertise fertility to males with visual behavioral cues, pheromones, or both. This period of advertised fertility is known as "oestrus", "estrus" or "heat". In species that experience estrus, females are generally only receptive to copulation while they are in heat (dolphins are an exception). In the estrous cycles of most placental mammals, if no fertilization takes place, the uterus reabsorbs the endometrium. This breakdown of the endometrium without vaginal discharge is sometimes called "covert menstruation". Overt menstruation (where there is blood flow from the vagina) occurs primarily in humans and close evolutionary relatives such as chimpanzees. Some species, such as domestic dogs, experience small amounts of vaginal bleeding while approaching heat; this discharge has a different physiologic cause than menstruation.
The red deer, one of five native deer species, is the biggest non-marine mammal in Wales. Fallow, muntjac roe and sika deer can also be found. Polecats and pine martens are very rarely seen. Other mammals include badgers, foxes, hares, hedgehogs, otters, rabbits, stoats, weasels, red squirrels, and 13 species of bat.
In biology, a hermaphrodite () is an organism that has complete or partial reproductive organs and produces gametes normally associated with both male and female sexes. Many taxonomic groups of animals (mostly invertebrates) do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the "female" or "male." For example, the great majority of tunicates, pulmonate snails, opisthobranch snails, earthworms and slugs are hermaphrodites. Hermaphroditism is also found in some fish species and to a lesser degree in other vertebrates. Most plants are also hermaphrodites.
This makes it easier for the team to work. Among their discoveries, they find out that the hermaphroditic hrossa typically give birth to only one child in a lifetime, and few die early. The occasional second birth makes up for those that do, and the population thus tends to remain stable. Going on a hunt with the hrossa, they learn that they hunt by transmitting a message of "hunger", which brings animals sacrificially to them. The hrossa have sexual intercourse with the animals, and then beat them with a club. The Quakers also tell many stories to the hrossa, hoping to trigger a response and learn more about the planet's natives. Finally, at Thanksgiving, the team leaves back to Swarthmore, and explain their findings to the town.
Protogynous hermaphrodites are animals that are born female and at some point in their lifespan change sex to male. As the animal ages, based on internal or external triggers, it shifts sex to become a male animal. Male fecundity increases greatly with age, unlike female.
"Triops cancriformis" has a very fast life cycle, and individuals become mature in about two weeks after hatching. Their populations can be gonochoric, hermaphroditic or androdioecious. The latter is a very rare reproductive mode in animals, in which populations are made of hermaphrodites, with a small proportion of males. Due to this lack of males, early researchers thought Triops were parthenogenetic. The presence of testicular lobes scattered amongst their ovaries confirmed they were in fact hermaphroditic. Fertilized females or hermaphrodites produce diapausing eggs or cysts, able to survive decades in the sediment of the ponds and lakes they inhabit. These eggs are resistant to drought and temperature extremes.