Cichlids are fish from the family Cichlidae in the order Cichliformes. Traditionally Cichlids were classed in a suborder, the Labroidei, along with the wrasses (Labridae), in the order Perciformes, but molecular studies have contradicted this grouping. On the basis of fossil evidence, it first appeared in Tanzania during the Eocene epoch, about 46–45 million years ago. The closest living relative of cichlids is probably the convict blenny, and both families are classified in the 5th edition of Fishes of the World as the two families in the Cichliformes, part of the subseries Ovalentaria. This family is large, diverse, and widely dispersed. At least 1,650 species have been scientifically described, making it one of the largest vertebrate families. New species are discovered annually, and many species remain undescribed. The actual number of species is therefore unknown, with estimates varying between 2,000 and 3,000.
Lake Baikal is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the Republic of Buryatia to the southeast. At 31,722 km2 (12,248 sq mi)—slightly larger than Belgium—Lake Baikal is the world's seventh-largest lake by surface area. However, because it is also the deepest lake, with a maximum depth of 1,642 metres, Lake Baikal is the world's largest freshwater lake by volume, containing 23,615.39 km3 (5,670 cu mi) of water or 22–23% of the world's fresh surface water, more than all of the North American Great Lakes combined. It is also the world's oldest lake at 25–30 million years. and among the clearest.
Daphnia is a genus of small planktonic crustaceans, 0.2–6.0 mm (0.01–0.24 in) in length. Daphnia are members of the order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their saltatory swimming style resembles the movements of fleas. Daphnia spp. live in various aquatic environments ranging from acidic swamps to freshwater lakes and ponds.
Lake Tanganyika is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all cases after Lake Baikal in Siberia. It is the world's longest freshwater lake. The lake is shared among four countries—Tanzania, the Democratic Republic of the Congo (DRC), Burundi, and Zambia, with Tanzania (46%) and DRC (40%) possessing the majority of the lake. It drains into the Congo River system and ultimately into the Atlantic Ocean.
The double-crested cormorant is a member of the cormorant family of water birds. It is found near rivers and lakes, and in coastal areas, and is widely distributed across North America, from the Aleutian Islands in Alaska down to Florida and Mexico. Measuring 70–90 cm (28–35 in) in length, it is entirely black except for a bare patch of orange-yellow facial skin and some extra plumage that it exhibits in the breeding season, when it grows a double crest in which black feathers are mingled with white. Five subspecies are recognized. It mainly eats fish and hunts by swimming and diving. Its feathers, like those of all cormorants, are not waterproof and it must spend time drying them out after spending time in the water. Once threatened by the use of DDT, the numbers of this bird have increased markedly in recent years.
The northern shoveler, known simply in Britain as the shoveler, is a common and widespread duck. It breeds in northern areas of Europe and across the Palearctic and across most of North America, wintering in southern Europe, the Indian subcontinent, Southeast Asia, Central, the Caribbean, and northern South America. It is a rare vagrant to Australia. In North America, it breeds along the southern edge of Hudson Bay and west of this body of water, and as far south as the Great Lakes west to Colorado, Nevada, and Oregon.
Cyprinus is the genus of typical carps in family Cyprinidae. Most species in the genus are of East Asia origin with only the common carp in Western Asia and Europe; this invasive species has also been introduced to many other regions around the world. Cyprinus are closely related to some more barb-like genera, such as Cyclocheilichthys and Barbonymus (tinfoils). The crucian carps (Carassius) of western Eurasia, which include the goldfish, are apparently not as closely related.
The scoters are stocky seaducks in the genus Melanitta. The drakes are mostly black and have swollen bills, the females are brown. They breed in the far north of Europe, Asia, and North America, and winter farther south in temperate zones of those continents. They form large flocks on suitable coastal waters. These are tightly packed, and the birds tend to take off together. Their lined nests are built on the ground close to the sea, lakes or rivers, in woodland or tundra. These species dive for crustaceans and molluscs.
The ruddy shelduck, known in India as the Brahminy duck, is a member of the family Anatidae. It is a distinctive waterfowl, 58 to 70 cm in length with a wingspan of 110 to 135 cm. It has orange-brown body plumage with a paler head, while the tail and the flight feathers in the wings are black, contrasting with the white wing-coverts. It is a migratory bird, wintering in the Indian subcontinent and breeding in southeastern Europe and central Asia, though there are small resident populations in North Africa. It has a loud honking call.
Hydrilla (waterthyme) is a genus of aquatic plant, usually treated as containing just one species, Hydrilla verticillata, though some botanists divide it into several species. It is native to the cool and warm waters of the Old World in Asia, Africa and Australia, with a sparse, scattered distribution; in Australia from Northern Territory, Queensland, and New South Wales.
Marimo is a rare growth form of Aegagropila linnaei in which the algae grow into large green balls with a velvety appearance.
Salvadori's teal or Salvadori's duck, is a species of bird endemic to New Guinea. It is placed in the monotypic genus Salvadorina.
The quagga mussel is a species of freshwater mussel, an aquatic bivalve mollusk in the family Dreissenidae. It has an average lifespan of 3 to 5 years.
Lake Lanao is a large ancient lake in the province of Lanao del Sur, Philippines. With a surface area of 340 km2 (130 sq mi), it is the largest lake in Mindanao, the deepest and second largest lake in the Philippines and counted as one of the 15 ancient lakes in the world. Scholars have been pushing for the lake's inclusion in the UNESCO World Heritage List. The lake's native people call themselves the Maranao or Meranaw. Their name was derived from the name of the lake, meaning "the people living around the lake".
Stentor, sometimes called trumpet animalcules, are a genus of filter-feeding, heterotrophic ciliates, representative of the heterotrichs. They are usually horn-shaped, and reach lengths of two millimeters; as such, they are among the largest known extant unicellular organisms. They reproduce asexually through binary fission.
The Gemmatimonadota are a phylum of bacteria established in 2003. The phylum contains two classes Gemmatimonadetes and Longimicrobia.
Hemitaeniochromis urotaenia is a species of fish endemic to Lake Malawi in East Africa. It is the type species of the genus Hemitaeniochromis, and is part of family Cichlidae in subfamily Pseudocrenilabrinae and the tribe Haplochromini.
A caiman is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family, the other being alligators. Caimans inhabit Mexico and Central & South America from marshes and swamps to mangrove rivers and lakes. They have scaly skin and live a fairly nocturnal existence. They are relatively small-sized crocodilians with an average maximum weight of 6 to 40 kg depending on species, with the exception of the black caiman, which can grow more than 4 m (13 ft) in length and weigh in excess of 1,000 kg. The black caiman is the largest caiman species in the world and is found in the slow-moving rivers and lakes that surround the Amazon basin. The smallest species is the Cuvier's dwarf caiman, which grows to 1.2 to 1.5 m long. There are six different species of caiman found throughout the watery jungle habitats of Central and Southern America. The average length for most of the other caiman species is about 2 to 2.5 m long.
Faxonius virilis is a species of crayfish known as the virile crayfish, northern crayfish,eastern crayfish, and lesser known as the lake crayfish or common crawfish. Faxonius virilis was reclassified in August 2017, and the genus was changed from Orconectes to Faxonius. It is native to the central United States, east to tributaries of Lake Erie, Lake Ontario, Lake Champlain and the St. Lawrence River in New York and to much of Canada.
Pallaseopsis quadrispinosa is a species of crustacean belonging to the family Pallaseidae.
