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Maccoa Duck
The Maccoa duck (''Oxyura maccoa'') is a stiff-tailed diving duck found across Eastern and Southern Africa. Description As members of the stiff-tailed duck group, Maccoas are often found wading in the water with their tail feathers cocked upwards. As diving ducks, their bodies are specialized for being agile underwater swimmers and thus have sacrificed the characteristics that allow them to move well on land. As a result, their legs are set further back on their bodies which makes them awkward when walking out of water. Male The breeding male Maccoa stands out with its cobalt blue bill extending from a completely black head and throat. The breast and back are chestnut coloured while the underparts are often greyish-brown, the rump is dark brown, and the tail and feet are black. In flight, the male's off-white underwing feathers and white axillaries can be seen. Non-breeding males closely resemble the females, except for a few points: a darker crown and hints of chestnut colou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Campbell Eyton
Thomas Campbell Eyton JP, DL (10 September 1809 – 25 October 1880) was an English naturalist whose fields were cattle, fishes and birds. He was a friend and correspondent of Charles Darwin though he opposed his theories. Eyton was born at Eyton Hall, near Wellington, Shropshire. He studied at St John's College, Cambridge, where he was a contemporary and friend of Charles Darwin. After succeeding to the estate in 1855, Eyton built a large natural history museum at Eyton Hall that included a range of bird skins and skeletons, described as "one of the finest in Europe". Besides Darwin, Eyton enjoyed some correspondence with other naturalists including Louis Agassiz, Asa Gray, and Alfred Russel Wallace. Eyton published ''History of the Rarer British Birds'' (1836), ''A Monograph on the Anatidae, Or Duck Tribe'' (1838), ''A History of Oyster and Oyster Fisheries'' (1858) and ''Osteologia Avium'' (1871–78). He established in about 1842 the ''Herd Book of Hereford Cattle'', wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosquito Larva
Mosquitoes, the Culicidae, are a family of small flies consisting of 3,600 species. The word ''mosquito'' (formed by '' mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mosquitoes have a slender segmented body, one pair of wings, three pairs of long hair-like legs, and specialized, highly elongated, piercing-sucking mouthparts. All mosquitoes drink nectar from flowers; females of some species have in addition adapted to drink blood. The group diversified during the Cretaceous period. Evolutionary biologists view mosquitoes as micropredators, small animals that parasitise larger ones by drinking their blood without immediately killing them. Medical parasitologists view mosquitoes instead as vectors of disease, carrying protozoan parasites or bacterial or viral pathogens from one host to another. The mosquito life cycle consists of four stages: egg, larva, pupa, and adult. Eggs are laid on the water surface; they hatch into motile larvae that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birds Of Southern Africa
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a four-chambered heart, and a strong yet lightweight Bird skeleton, skeleton. Birds live worldwide and range in size from the bee hummingbird to the common ostrich. There are over 11,000 living species and they are split into 44 Order (biology), orders. More than half are passerine or "perching" birds. Birds have Bird wing, wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the Flightless bird, loss of flight in some birds, including ratites, penguins, and diverse endemism, endemic island species. The digestive and respiratory systems of birds are also uniquely a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birds Of East Africa
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the common ostrich. There are over 11,000 living species and they are split into 44 orders. More than half are passerine or "perching" birds. Birds have wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have furt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxyurinae , a tribe of ducks in the family Anatidae
{{Disambiguation, geo ...
Oxyurinae may refer to: * Oxyuridae, a family of nematode worms * Oxyurini The Oxyurini are a tribe of the duck subfamily of birds, the Anatinae. It has been subject of considerable debate about its validity and circumscription. Some taxonomic authorities place the group in its own subfamily, the ''Oxyurinae''. Most of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gillnetting
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is generally referred to as a "cork line." The line along the bottom of the panels is generally weighted. Traditionally this line has been weighted with lead and may be referred to as "lead line." A gillnet is normally set in a straight line. Gillnets can be characterized by mesh size, as well as colour and type of filament from which they are made. Fish may be caught by gillnets in three ways: # Wedged – held by the mesh around the body. # Gilled – held by mesh slipping behind the opercula. # Tangled – held by teeth, spines, maxillaries, or other protrusions without the body penetrating the mesh. Most fish have gills. A fish swims into a net and passes only part way through the mesh. When it struggles to free itself ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygyny In Animals
Polygyny (; from Neo-Greek , ) is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.Clutton-Brock T.H. (1989). ‘Review lecture: mammalian mating systems.' ''Proceedings of the Royal Society of London''. Series B, Biological Sciences 236: 339–372. Polygyny is typical of one-male, multi-female groupsBoyd, R., & Silk, J. B. (2009). How Humans Evolved (preferably the downloadable pdf version): WW Norton & Company, New York. and can be found in many species including: elephant seal, spotted hyena, gorilla, red-winged prinia, house wren, hamadryas bab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ostracod
Ostracods, or ostracodes, are a Class (biology), class of the crustacean, Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 33,000 species (only 13,000 of which are extant taxon, extant) have been identified,Brandão, S.N.; Antonietto, L.S; Nery, D.G.; Santos, S.G.; Karanovic, I. (2023). World Ostracoda Database. Accessed at https://www.marinespecies.org/ostracoda on 2023-09-12. grouped into 7 valid orders. They are small crustaceans, typically around in size, but varying from , the latter in the case of the marine ''Gigantocypris.'' The largest known freshwater species is ''Megalocypris princeps'', which reach 8 mm in length. In most cases, their bodies are flattened from side to side and protected by a bivalve-like valve or "shell" made of chitin, and often calcium carbonate. The family Entocytheridae and many planktonic forms do not have calcium carbonate. The hinge of the two valves is in the upper (dorsal) region of the body. Ostracods are grouped toget ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropoda
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the land. There are many thousands of species of sea snails and sea slug, slugs, as well as freshwater snails, freshwater limpets, land snails and slugs. The class Gastropoda is a diverse and highly successful class of mollusks within the phylum Mollusca. It contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Furongian, Late Cambrian. , 721 family (taxonomy), families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently neontology, extant living fossil, with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daphnia
''Daphnia'' is a genus of small planktonic crustaceans, in length. ''Daphnia'' are members of the Order (biology), order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their Saltation (gait), saltatory swimming style resembles the movements of fleas. ''Daphnia'' spp. live in various aquatic environments ranging from acidic swamps to Fresh water, freshwater lakes and ponds. The two most commonly found species of ''Daphnia'' are ''Daphnia pulex, D. pulex'' (small and most common) and ''Daphnia magna, D. magna'' (large). They are often associated with a related genus in the order Cladocera: ''Moina'', which is in the Moinidae group instead of the Daphniidae, and is much smaller than ''D. pulex'' (roughly half the maximum length). Appearance and characteristics The body of a ''Daphnia'' species is usually long, and is divided into Segmentation (biology), segments, although this division is not visible. The hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubifex
''Tubifex'' is a cosmopolitan genus of tubificid annelids that inhabits the sediments of lakes, rivers and occasionally sewer lines. At least 13 species of ''Tubifex'' have been identified, with the exact number not certain, as the species are not easily distinguishable from each other. Reproduction ''Tubifex'' worms are hermaphroditic: each individual has both male (testes) and female (ovaries) organs in the same animal. These minute reproductive organs are attached to the ventral side of the body wall in the celomic cavity. In mature specimens, the reproductive organs are clearly found on the ventral side of the body. Copulation and cocoon formation Although the ''Tubifex'' worms are hermaphrodites, the male and female organs become mature at different times; thus self-fertilization is avoided, and cross-fertilization is encouraged. Two mature ''Tubifex'' worms undergo copulation by joining ventral and anterior surfaces together with their anterior ends pointing opposite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygonum
''Polygonum'' is a genus of about 130 species of flowering plants in the buckwheat and knotweed family Polygonaceae. Common names include knotweed and knotgrass (though the common names may refer more broadly to plants from Polygonaceae). In the Middle English glossary of herbs ''Alphita'' ( 1400–1425), it was known as ars-smerte. There have been various opinions about how broadly the genus should be defined. For example, buckwheat (''Fagopyrum esculentum'') has sometimes been included in the genus as ''Polygonum fagopyrum''. Former genera such as ''Polygonella'' have been subsumed into ''Polygonum''; other genera have been split off. The genus primarily grows in northern temperate regions. The species are very diverse, ranging from prostrate herbaceous annual plants to erect herbaceous perennial plants. ''Polygonum'' species are occasionally eaten by humans, and are used as food plants by the larvae of some Lepidoptera species – see list. Most species are considered weeds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
