| Ayarnangra estuarius | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Siluriformes |
| Family: | Erethistidae |
| Genus: | Ayarnangra T. R. Roberts, 2001 |
| Species: | A. estuarius |
| Binomial name | |
| Ayarnangra estuarius T. R. Roberts, 2001 | |
Ayarnangra estuarius is a species of catfish (order Siluriformes) of the family Erethistidae. It is the only member of the monotypic genus Ayarnangra.
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. While these definitions may seem adequate, when looked at more closely they represent problematic species concepts. For example, the boundaries between closely related species become unclear with hybridisation, in a species complex of hundreds of similar microspecies, and in a ring species. Also, among organisms that reproduce only asexually, the concept of a reproductive species breaks down, and each clone is potentially a microspecies.
Catfish are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, the Mekong giant catfish from Southeast Asia, the wels catfish of Eurasia, and the piraíba of South America, to detritivores, and even to a tiny parasitic species commonly called the candiru, Vandellia cirrhosa. Neither the armour-plated types nor the naked types have scales. Despite their name, not all catfish have prominent barbels. Members of the Siluriformes order are defined by features of the skull and swimbladder. Catfish are of considerable commercial importance; many of the larger species are farmed or fished for food. Many of the smaller species, particularly the genus Corydoras, are important in the aquarium hobby. Many catfish are nocturnal, but others are crepuscular or diurnal.
In biological classification, the order is
- a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family. An immediately higher rank, superorder, may be added directly above order, while suborder would be a lower rank.
- a taxonomic unit, a taxon, in that rank. In that case the plural is orders.
A. estuarius is endemic to Myanmar where it is found in the large tidal rivers in the lower Ayeyarwady River. [1] This species feeds on comparatively large invertebrates. [1]
Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, which applies to species that are restricted to a defined geographical area.
Myanmar, officially the Republic of the Union of Myanmar and also known as Burma, is a country in Southeast Asia. Myanmar is bordered by India and Bangladesh to its west, Thailand and Laos to its east and China to its north and northeast. Myanmar is the largest of the mainland Southeast Asian states. To its south, about one third of Myanmar's total perimeter of 5,876 km (3,651 mi) forms an uninterrupted coastline of 1,930 km (1,200 mi) along the Bay of Bengal and the Andaman Sea. The country's 2014 census counted the population to be 51 million people. As of 2017, the population is about 54 million. Myanmar is 676,578 square kilometres in size. Its capital city is Naypyidaw, and its largest city and former capital is Yangon (Rangoon). Myanmar has been a member of the Association of Southeast Asian Nations (ASEAN) since 1997.
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun, and the rotation of the Earth.
A. estuarius has no thoracic adhesive apparatus, a granulate anterior margin of the pectoral fin spine, a smooth to granulate anterior margin of the dorsal fin spine, a slender body shape, moderate gill openings, and a papillate upper lip. The eyes are very small, and the nostrils are much larger than the eyes. [2] This species of fish reaches a length of 4.59 centimetres (1.81 in) SL. [1]
The thorax or chest is a part of the anatomy of humans and various other animals located between the neck and the abdomen. The thorax includes the thoracic cavity and the thoracic wall. It contains organs including the heart, lungs, and thymus gland, as well as muscles and various other internal structures. Many diseases may affect the chest, and one of the most common symptoms is chest pain.
A dorsal fin is a fin located on the back of most marine and freshwater vertebrates such as fishes, cetaceans, and the (extinct) ichthyosaur. Most species have only one dorsal fin, but some have two or three.
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water and excretes carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a large surface area to the external environment. Branchia is the zoologists' name for gills.
