Blue is one of the three primary colours in the RYB colour model, as well as in the RGB (additive) colour model. It lies between violet and cyan on the spectrum of visible light. The term blue generally describes colours perceived by humans observing light with a dominant wavelength that’s between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; azure contains some green, while ultramarine contains some violet. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. An optical effect called the Tyndall effect explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective.
The Sardinian warbler is a common and widespread typical warbler from the Mediterranean region. Like most Curruca species, it has distinct male and female plumages. The adult male has a grey back, whitish underparts, black head, white throat and red eyes. Plumages are somewhat variable even in the same locality, with the intensity of a reddish hue on upper- and/or underside that varies from absent to pronounced. The female is mainly brown above and buff below, with a grey head. The Sardinian warbler's song is fast and rattling, and is very characteristic of the Mediterranean areas where this bird breeds.
A tunicate is an exclusively marine invertebrate animal, a member of the subphylum Tunicata. This grouping is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords. The subphylum was at one time called Urochordata, and the term urochordates is still sometimes used for these animals. They are the only chordates that have lost their myomeric segmentation, with the possible exception of the seriation of the gill slits. However, doliolids still display segmentation of the muscle bands.
Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of a polysaccharide.
Hidden text is computer text that is displayed in such a way as to be invisible or unreadable. Hidden text is most commonly achieved by setting the font colour to the same colour as the background, rendering the text invisible unless the user highlights it.
Herdmania is a genus of ascidian tunicates in the family Pyuridae.
The golden-headed quetzal or corequenque is a strikingly coloured bird in the genus Pharomachrus. It is found in moist mid-elevation forests from eastern Panama to northern Bolivia.
Ciona intestinalis is an ascidian, a tunicate with very soft tunic. Its Latin name literally means "pillar of intestines", referring to the fact that its body is a soft, translucent column-like structure, resembling a mass of intestines sprouting from a rock. It is a globally distributed cosmopolitan species. Since Linnaeus described the species, Ciona intestinalis has been used as a model invertebrate chordate in developmental biology and genomics. Studies conducted between 2005 and 2010 have shown that there are at least two, possibly four, sister species. More recently it has been shown that one of these species has already been described as Ciona robusta. By anthropogenic means, the species has invaded various parts of the world and is known as an invasive species.
The desert tree frog, or little red tree frog, is a species of tree frog native to Australia, southern New Guinea, and Timor. It is one of Australia's most widely distributed frogs, inhabiting northern Australia, including desert regions and much of temperate eastern Australia. It is one of the few Australian tree frogs to inhabit arid, tropical, and temperate climates.
The red-chested cuckoo is a species of cuckoo in the family Cuculidae. It is a medium-sized bird found in Africa, south of the Sahara. In Afrikaans, it is known as "Piet-my-vrou", after its call.
The grayish or gray mouse opossum is a diminutive species of opossum in the family Didelphidae, endemic to Mexico. It is the sole species of its monotypic genus, Tlacuatzin.
Lactarius quietus is a mushroom of the genus Lactarius. It is easily identified by its oily scent and the concentric bands on its cap. It is brown, and is probably named after its matte, "quiet" surface and colouration. It is found exclusively under oak trees in Europe, where it grows solitarily or in scattered groups in autumn months. In North America, the variety L. quietus var. incanus is fairly common in the same habitat. The mushroom's edibility is disputed.
Pyura stolonifera, commonly known in South Africa as "red bait", is a sessile ascidian, or sea squirt, that lives in coastal waters attached to rocks or artificial structures. Sea squirts are named for their habit of squirting a stream of water from their exhalant siphons when touched at low tide.
Styela montereyensis, also called the stalked tunicate, Monterey stalked tunicate, and the long-stalked sea squirt is a solitary ascidian tunicate. It has a cylindrical, yellow to dark reddish-brown body and a thin trunk that anchors it to rocks. It is found in subtidal areas of the western coast of North America from Vancouver Island to Baja California.
Ciona savignyi is a marine animal sometimes known as the Pacific transparent sea squirt or solitary sea squirt. It is a species of tunicates in the family Cionidae. It is found in shallow waters around Japan and has spread to the west coast of North America where it is regarded as an invasive species.
Ctenophorus decresii, also known commonly as the tawny dragon or the tawny crevice-dragon, is a species of lizard in the family Agamidae. The species is endemic to Australia. The average snout-to-vent length (SVL) of the species is 80.76 mm (3.180 in) with larger individuals being around 89 mm (3.5 in) and smaller individuals around 72 mm (2.8 in). The optimal time for mating in this species is two to three weeks after the females emerge from hibernation. Eggs are typically laid from September to October with most of them being laid earlier in the period. C. decresii is known for its variations in throat colours which change based on environmental conditions. Its primary food sources consist of both vegetation and invertebrates, and it prefers to live in rocky habitats.
Dendrodoa grossularia is a species of tunicate or sea squirt in the family Styelidae, commonly known as the baked bean ascidian. It is native to the northeastern Atlantic Ocean where it is common in shallow water and on the lower shore in exposed rocky sites.
Phallusia mammillata is a solitary marine tunicate of the ascidian class found in the eastern Atlantic Ocean and the Mediterranean Sea.
Lamellaria perspicua, commonly known as the transparent lamellaria, is a species of small, slug-like sea snail, a marine gastropod mollusc in the family Velutinidae. It is native to the northeastern Atlantic Ocean and the Mediterranean Sea, where it feeds on colonial ascidians.
Halocynthia igaboja, commonly known as sea hedgehog, bristly tunicate or spiny sea squirt, is a species of tunicate in the family Pyuridae. It is native to the northeastern Pacific Ocean. This species was first described in 1906 by the Japanese marine biologist Asajiro Oka, who gave it the name Cynthia ritteri. It was later transferred to the genus Halocynthia.
