Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from 8.5 μm (0.00033 in) to 33.6 m (110 ft). They have complex ecologies and interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology, and the study of animal behaviors is known as ethology.
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The Tasmanian devil (Sarcophilus harrisii) (palawa kani: purinina) is a carnivorous marsupial of the family Dasyuridae. It was formerly present across mainland Australia, but became extinct there around 3,500 years ago. The size of a small dog, the Tasmanian devil became the largest carnivorous marsupial in the world following the extinction of the thylacine in 1936. It is related to quolls, and distantly related to the thylacine. It is characterised by its stocky and muscular build, black fur, pungent odour, extremely loud and disturbing screech, keen sense of smell, and ferocity when feeding. The Tasmanian devil's large head and neck allow it to generate among the strongest bites per unit body mass of any extant predatory land mammal. It hunts prey and scavenges on carrion.
Although devils are usually solitary, they sometimes eat and defecate together in a communal location. Unlike most other dasyurids, the devil thermoregulates effectively, and is active during the middle of the day without overheating. Despite its rotund appearance, it is capable of surprising speed and endurance, and can climb trees and swim across rivers. Devils are not monogamous. Males fight one another for females, and guard their partners to prevent female infidelity. Females can ovulate three times in as many weeks during the mating season, and 80% of two-year-old females are seen to be pregnant during the annual mating season. (Full article...)
Aplysina archeri is a species of sponge that has long tube-like structures of cylindrical shape. Many tubes are attached to one particular part of the organism; a single tube can grow up to 5 feet (1.5 m) high and 3 inches (7.6 cm) thick. These sponges mostly live in the Atlantic Ocean. These filter feeders eat food such as plankton or suspended detritus as it passes them.
Cymbiola nobilis is a species of sea snail in the familyVolutidae. Found in the Pacific Ocean, from Taiwan to Singapore, it averages 6 centimetres (2.4 in) in length; females are larger than males. Because the shell is commonly collected, there has been an overharvesting of the snail, and it is now considered vulnerable.
The Osprey (Pandion haliaetus) is a medium large raptor which is a specialist fish-eater with a worldwide distribution. It is often known by other colloquial names such as Fish Hawk, Sea Hawk or Fish Eagle.
The Osprey is particularly well adapted to its diet, with reversible outer toes, closable nostrils to keep out water during dives, and backwards facing scales on the talons which act as barbs to help catch fish.
The bird-cherry ermine (Yponomeuta evonymella) is a species of moth in the family Yponomeutidae, native to Europe and parts of Asia. The caterpillars are gregarious and feed on the leaves of the bird cherry tree, forming silken webbing for their own protection. They create further webbing on the trunk and near the base of the tree, which hides them as they pupate. This photograph shows one of many bird-cherry ermine caterpillar nests on a tree in Lahemaa National Park, Estonia. In some years, they are so numerous that they can completely strip a tree of its foliage.
The common clam worm (Alitta succinea) is a widely distributed species of marine polychaete worm. The photograph shows an epitoke specimen, the worm having turned into a form capable of reproduction. After releasing its sperm or eggs, the animal will die.
The coconut octopus (Amphioctopus marginatus) is a medium-sized cephalopod found in tropical waters of the western Pacific Ocean. It commonly preys upon shrimp, crabs, and clams, and displays unusual behaviour, including bipedal walking and gathering and using coconut shells and seashells for shelter.
A macro view of a Gonia capitatafly feeding on honey, showing its proboscis and pedipalps (the two appendages protruding from the proboscis), two types of insect mouthparts. The proboscis actually comprises the labium, a quadrupedal structure, and a sponge-like labellum at the end. Flies eat solid food by secreting saliva and dabbing it over the food item. As the saliva dissolves the food, the solution is then drawn up into the mouth as a liquid. The labellum's surface is covered by minute food channels which form a tube leading to the esophagus, and food is drawn up the channels by capillary action.
The golden toad (Bufo periglenes) is an extinct species of true toad that was once abundant in a small region of high-altitude cloud-covered tropical forests, about 30 km2 (12 sq mi) in area, above the city of Monteverde, Costa Rica. The last reported sighting of a golden toad was on 15 May 1989. Its sudden extinction may have been caused by chytrid fungus and extensive habitat loss.
Haliotis laevigata is a species of marine mollusc in the family Haliotidae, endemic to Tasmania and the southern and western coasts of Australia. This picture shows five views of a green H. laevigata shell, 7.5 centimetres (3.0 in) in length. The holes in the shell, characteristic of abalones, are respiratory apertures for venting water from the gills and for releasing sperm and eggs into the water column.
The rock hyrax (Procavia capensis), also known as the dassie, is one of four living species of the order Hyracoidea, and the only living species in its genus. Like all hyraxes, it is a medium-sized terrestrial mammal between 4 kilograms (9 lb) and 5 kilograms (11 lb) in mass, with short ears and tail. The rock hyrax is found across Africa and the Middle East, at elevations up to 4,200 metres (13,800 ft). It resides in habitats with rock crevices which it uses to escape from predators. Along with the other hyrax species and the manatee, these are the animals most closely related to the elephant.
Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics. Differences may include secondary sex characteristics, size, weight, color, or markings, as well as behavioral and cognitive differences. In the butterfly species Colias dimera (also known as the Dimera sulphur), seen here mating in Venezuela, the male on the right is a brighter shade of yellow than the female.
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, platy, meaning "flat" and ἕλμινς (root: ἑλμινθ-), helminth-, meaning "worm") are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Being acoelomates (having no body cavity), and having no specialised circulatory and respiratoryorgans, they are restricted to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food can not be processed continuously. (Full article...)
Thysanozoon nigropapillosum, the yellow-spotted flatworm, is a species of marine flatworm in the family Pseudocerotidae. The species is native to the tropical Indo-Pacific region, where it lives in shallow reef habitats. Flatworms are hermaphrodites, each being able to act as either male or female. As a donor of sperm, it can grip the margin of the recipient's body, using its two penises in a chopstick-like manner, and deposit sperm on the surface of the skin of the recipient, even while it is actively swimming.
This picture shows a yellow-spotted flatworm photographed in Manta Ray Bay, on the island of Yap in the Federated States of Micronesia. The flatworm is seen swimming to the right at a depth of 12 metres (40 ft) by undulating the margins of its body. The pseudotentacles at the front have simple eyes and sensory receptors to enable the flatworm to find tunicates on which it feeds.
The brown pelican (Pelecanus occidentalis) is a bird of the pelican family, Pelecanidae, one of three species found in the Americas and one of two that feed by diving into water. This photograph shows a juvenile brown pelican gliding over the Pacific Ocean at Bodega Head, California.
After hatching, the pelican chicks are fed on regurgitated predigested fish and take about two months to fledge. When they leave the nest, they are at first unable to fly and take wing several weeks later. When the parents cease to feed them, some six months later, each will have consumed around 70 kg (150 lb) of fish. The juvenile brown pelican does not acquire adult plumage until three years of age, when the feathers on the neck become paler, the upperparts striped, the wing feathers grayer, and the belly acquires dark spots.
Brittle stars, serpent stars, or ophiuroids (from Latin ophiurus 'brittle star'; from Ancient Greekὄφις (óphis) 'serpent', and οὐρά (ourá) 'tail'; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to 60 cm (24 in) in length on the largest specimens. (Full article...)
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquaticinvertebrate animals, nearly all living in sedentary colonies. Typically about 0.5 millimetres (1⁄64 in) long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869living species are known. Originally all of the crown group Bryozoa were colonial, but as an adaptation to a mesopsammal (interstitial spaces in marine sand) life or to deep‐sea habitats, secondarily solitary forms have since evolved. Solitary species has been described in four genera; Aethozooides, Aethozoon, Franzenella and Monobryozoon). The latter having a statocyst‐like organ with a supposed excretory function. (Full article...)
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The destruction of ivory is a technique used by governments and conservation groups to deter the poaching of elephants for their tusks and to suppress the illegal ivory trade. , more than 263 tonnes (580,000 lb) of ivory have been destroyed, typically by burning or crushing, in these high-profile events in 21 countries around the world. Kenya held the first event in 1989, as well as the largest event in 2016, when a total of 105 tonnes (231,000 lb) of ivory were incinerated.
The conservationists, governments, and non-governmental organizations that endorse the strategy argue that it fosters public support for the protection of elephants and that it sends a message to poachers their work is futile. Critics contend that the technique may increase poaching by creating a perception of scarcity that increases ivory's value on the black market, and that evidence for the technique's effectiveness is insufficient to justify the opportunity cost for countries struggling with poverty. (Full article...)
...that the Southern Giant Petrel is the leading predator to the Emperor Penguin, and may be responsible for up to 34% of chick deaths in some colonies?
...that some goats freeze for ten seconds whenever startled due to the genetic condition known as myotonia congenita, and have thus been dubbed "fainting goats"?
The following are images from various animal-related articles on Wikipedia.
Image 1The microscopic cave snail Zospeum tholussum, found at depths of 743 to 1,392 m (2,438 to 4,567 ft) in the Lukina Jama–Trojama cave system of Croatia, is completely blind with a translucent shell (from Fauna)
Image 7The black and yellow warning colours of the cinnabar moth caterpillar, Tyria jacobaeae, are avoided by some birds. (from Animal coloration)
Image 8The bilaterian gut develops in two ways. In many protostomes, the blastopore develops into the mouth, while in deuterostomes it becomes the anus. (from Animal)
Image 26A praying mantis in deimatic or threat pose displays conspicuous patches of colour to startle potential predators. This is not warning coloration as the insect is palatable. (from Animal coloration)
Image 45Idealised bilaterian body plan. With an elongated body and a direction of movement the animal has head and tail ends. Sense organs and mouth form the basis of the head. Opposed circular and longitudinal muscles enable peristaltic motion. (from Animal)
Image 46A brilliantly-coloured oriental sweetlips fish (Plectorhinchus vittatus) waits while two boldly-patterned cleaner wrasse (Labroides dimidiatus) pick parasites from its skin. The spotted tail and fin pattern of the sweetlips signals sexual maturity; the behaviour and pattern of the cleaner fish signal their availability for cleaning service, rather than as prey (from Animal coloration)
Image 47Linnaeus's table of the animal kingdom from the first edition of Systema Naturae (1735) (from Zoology)
The following table lists estimated numbers of described extant species for the animal groups with the largest numbers of species,[1] along with their principal habitats (terrestrial, fresh water,[2] and marine),[3] and free-living or parasitic ways of life.[4] Species estimates shown here are based on numbers described scientifically; much larger estimates have been calculated based on various means of prediction, and these can vary wildly. For instance, around 25,000–27,000 species of nematodes have been described, while published estimates of the total number of nematode species include 10,000–20,000; 500,000; 10 million; and 100 million.[5] Using patterns within the taxonomic hierarchy, the total number of animal species—including those not yet described—was calculated to be about 7.77 million in 2011.[6][7][a]
^The application of DNA barcoding to taxonomy further complicates this; a 2016 barcoding analysis estimated a total count of nearly 100,000 insect species for Canada alone, and extrapolated that the global insect fauna must be in excess of 10 million species, of which nearly 2 million are in a single fly family known as gall midges (Cecidomyiidae).[8]
^Stork, Nigel E. (January 2018). "How Many Species of Insects and Other Terrestrial Arthropods Are There on Earth?". Annual Review of Entomology. 63 (1): 31–45. doi:10.1146/annurev-ento-020117-043348. PMID28938083. S2CID23755007. Stork notes that 1m insects have been named, making much larger predicted estimates.
^ abcdNicol, David (June 1969). "The Number of Living Species of Molluscs". Systematic Zoology. 18 (2): 251–254. doi:10.2307/2412618. JSTOR2412618.
^Sluys, R. (1999). "Global diversity of land planarians (Platyhelminthes, Tricladida, Terricola): a new indicator-taxon in biodiversity and conservation studies". Biodiversity and Conservation. 8 (12): 1663–1681. doi:10.1023/A:1008994925673. S2CID38784755.