Portal:Biology/Previous pictures

This is a list of featured pictures from the Biology portal, sorted in reverse-chronological order.

April 28, 2013

An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination. In humans, it is called an embryo until about eight weeks after fertilization (i.e. ten weeks after the last menstrual period or LMP)

August 16, 2011

Chimaeras are cartilaginous fish in the order Chimaeriformes, known informally as ghost sharks, ratfish, spookfish, or rabbitfishes. They grow up to 150 cm (4.9 ft) in length, and have elongated, soft bodies, with a bulky head and a single gill-opening. For defense, most chimaeras have a venomous spine located in front of the dorsal fin. At one time a "diverse and abundant" group (based on the fossil record), their closest living relatives are sharks, though in evolutionary terms they branched off from sharks nearly 400 million years ago and have remained isolated ever since, typically confined to deep water.

April 1, 2011

The platypus (Ornithorhynchus anatinus) is a semi-aquatic mammal endemic to eastern Australia, including Tasmania. Together with the four species of echidna, it is one of the five extant species of monotremes, the only mammals that lay eggs instead of giving birth to live young. It is the sole living representative of its family (Ornithorhynchidae) and genus (Ornithorhynchus), though a number of related species have been found in the fossil record. The bizarre appearance of this egg-laying, venomous, duck-billed, beaver-tailed, otter-footed mammal baffled European naturalists when they first encountered it, with some considering it an elaborate fraud.

February 4, 2011

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The Warbler Finch (Certhidea olivacea) is the only member of the genus Certhidea and one of Darwin's finches, the group of 14 or 15 passerine birds first collected by Charles Darwin on the Galápagos Islands during the second voyage of the Beagle. Though sometimes classified in the family Emberizidae, more recent studies have shown it to belong in the tanager family, Thraupidae. Darwin had mistakenly thought it was a wren, but, on return to England, was informed in March 1837 by the ornithologist John Gould that the bird belonged to the group of finches.

January 10, 2011

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Naja naja or the Indian cobra is a species of venomous snake found in Indian subcontinent. It is one of the big four members and it is one of the species which are responsible for causing the most snakebite cases in India. This snake is revered in Indian mythology and culture and is often seen with snake charmers. It is now protected in India under the Indian Wildlife Protection Act (1972).

October 27, 2010

The purple-striped jelly (Chrysaora colorata, formerly Pelagia colorata) is a species of jellyfish existing primarily off the coast of California, USA, in Monterey Bay. The bell (body) of the jellyfish is up to 70 cm in diameter, typically with a radial pattern of stripes. The tentacles vary with the age of the individual, consisting typically of eight marginal long dark arms, and four central, frilly, oral arms.

April 24, 2008

Mayflies are insects assigned to the Order Ephemeroptera. They are related to dragonflies and damselflies. Their development takes place in freshwater and typically takes a year. During that time, they are known as "nymphs". The adults are short-lived, from a few hours to a few days depending on the species. About 2,500 species are known worldwide. Depicted here is a female subimago of the March Brown, Rhithrogena germanica, which is a faunistic rarity and on the red list of endangered species.

The plant shown is a horsetail, Equisetum arvense.

December 3, 2007

Photo credit: Keith Weller (USDA) Biodiversity is the diversity of and in living nature. Diversity, at its heart, implies the number of different kinds of objects, such as species. To increase the genetic diversity of U.S. corn, the Germplasm Enhancement for Maize (GEM) project seeks to combine exotic germplasm, such as this unusually colored and shaped maize from Latin America, with domestic corn lines.

April 23, 2007

Photo credit: BS Thurner Hof A male Indian Peafowl (Pavo cristatus) displaying its feathers. The tail feathers of the male are among the most studied sexually selected traits.

February 12, 2007

Photo credit: Janek Pfeifer A mating pair of European or Common Toads (Bufo bufo) occupying the position known as amplexus. This is indeed a common toad, with a range that includes North Africa, Europe except Ireland, and across North Asia into Siberia. In some regions, toads are threatened by roads disrupting their spawning migrations, and in many places, tunnels have been built to allow them to cross roads.

December 12, 2006

Photo credit: Mariana Ruiz Villarreal Two Centrosauri in an artist's impression of male combat.

October 12, 2006

Photo credit: Exlibris The vibrissae of a culpeo (Pseudalopex culpaeus), sometimes known as the Patagonian fox, a South American canid.

September 20, 2006

Photo credit: Ksoth A Panther chameleon (Furcifer pardalis) from Nosy Be, Madagascar, displaying mating colors.

2006-07-25

Photo credit: Bernard Landgraf The Red Panda (Ailurus fulgens) is a small bear-like mammal native to the Himalayas and southern China.

July 11, 2006

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Bloodroot (Sanguinaria canadensis) flowers are produced from March to May, with 8-12 delicate white petals and yellow stamens

May 19, 2006

A crab from the genus Mictyris that lives in the Indo-Pacific region.

April 10, 2006

Two flies of the family Anthomyiidae mating.

March 8, 2006

Three types of cell reproduction are compared: the relatively simple binary fission and two more complicated types that either involve mitosis or meiosis.

March 1, 2006

Fruit of the Horse Chestnut tree. The dried seeds are often used in the English children's game: Conker.

February 23, 2006

A female Superb Fairy-wren (Malurus cyaneus), seen here perched on barbed wire. This bird is native to Australia

February 8, 2006

A furry bumblebee gathers pollen.

January 30, 2006

Compound eye of the Antarctic krill Euphausia superba

January 23, 2006

A Caribbean Reef Squid (Sepioteuthis sepioidea), part of the family Loliginidae.

January 15, 2006

A polydactyl human hand.

January 5, 2006

An Antarctic Icefish (family Channichthyidae).

December 28, 2005

Two North American River Otters (Lontra canadensis)

December 26, 2005

A Chinstrap Penguin hunting for krill (Pygoscelis antarctica)

November 25, 2005

Side view of the Yellow-winged Darter (Sympetrum flaveolum)