Wrestling halfbeak | |
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Wrestling halfbeaks in an aquarium | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Beloniformes |
Family: | Zenarchopteridae |
Genus: | Dermogenys |
Species: | D. pusilla |
Binomial name | |
Dermogenys pusilla Kuhl & van Hasselt, 1823 | |
Synonyms [2] | |
Hemiramphus fluviatilis Bleeker, 1850 |
The wrestling halfbeak (Dermogenys pusilla) also known as Malayan halfbeak is a species of viviparous halfbeak native to the fresh and brackish waters of rivers and coastal regions in South-East Asia, in Singapore, Thailand, Indonesia, Thailand, Malaysia, Borneo and Sumatra. [2] [3] It is a small, slender, livebearing fish, with the elongated lower jaw characteristic of its family. The colour of this species varies, depending on where the specimen is found. [4] It is the type species of the genus Dermogenys . [5]
Wrestling halfbeaks are surface-feeding fish and feed on a variety of small invertebrates including crustaceans and insect larvae, but especially mosquito larvae and flying insects that have fallen onto the surface of the water. [6] As with all halfbeaks, the upper jaw lifts upwards when the fish is opening its mouth. Wrestling halfbeaks are livebearing fish, the females giving birth to around twenty offspring after a gestation period of about a month. [7] [8] [9]
Wrestling halfbeaks are sexually dimorphic. The females are larger than the males and grow up to 7 cm (3 in) long; males only reach about 5.5 cm (2.2 in) and typically has red or yellow patches on the dorsal fin and the beak. [10] [11] The males of wrestling halfbeaks will fight among themselves by locking jaws, hence their name, for up to thirty minutes.
This species was described as Dermogenys pusillus by Heinrich Kuhl and Johan Coenraad van Hasselt in 1823 with the type locality given as Bogor, Java, the name was subsequently amended to the feminine form. [12]
In the wild, and in large aquaria, the weaker male will quickly disengage and swim away, and fights therefore rarely result in serious injury to either party. However, in their native range, local people sometimes use wrestling halfbeaks as fighting fish for betting purposes (like fighting cocks or siamese fighting fish). [13] [14]
Wrestling halfbeaks, as well as other species in the genus Dermogenys, are quite widely traded as aquarium fish, sometimes under the "silver halfbeak" or "golden halfbeak" names, depending on the colouration of the fish. As with all freshwater halfbeaks, these fish are sensitive to sudden changes in pH and hardness, but they are otherwise adaptable, and can be maintained in anything from soft and acid freshwater through to slightly brackish water. [15] [16] When first introduced into the aquarium, wrestling halfbeaks are nervous fish that tend to be timid. They may swim frantically if suddenly frightened, even crashing into the walls. However, once they are used to their surroundings, they become lively, easy to care for fish. [17] [18]
Livebearers are aquarium fish that retain the eggs inside the body and give birth to live, free-swimming young. Among aquarium fish, livebearers are nearly all members of the family Poeciliidae and include guppies, mollies, platies and swordtails.
Beloniformes is an order composed of six families of freshwater and marine ray-finned fish:
Anablepidae is a family of fishes which live in brackish and freshwater habitats from southern Mexico to southern South America. There are three genera with sixteen species: the four-eyed fishes, the onesided livebearers and the white-eye, Oxyzygonectes dovii. Fish of this family eat mostly insects and other invertebrates.
Dermogenys is a genus of viviparous halfbeaks. They are widely distributed in fresh and brackish water in South and Southeast Asia, ranging from India to the Philippines and Greater Sundas. They are all viviparous, producing small clutches of up to 30 fry that closely resemble the adults, except they are much smaller, around 1–1.5 cm (0.4–0.6 in) in length. Adults are typically around 6–7 cm (2.4–2.8 in) in length, with females being slightly larger than males. Males tend to be more brightly coloured and are well known for being aggressive towards one another. The wrestling halfbeak, D. pusilla, is widely used in Asia as fighting animals upon which wagers are placed. Both sexes have lower jaws (mandibles) that are much longer than the upper ones, and from this comes the "halfbeak" name.
The Freshwater Needlefish,, is a species of needlefish found in freshwater and brackish habitats in South and Southeast Asia.
Limia is a genus of livebearing fishes belonging to the Cyprinodontiform family Poeciliidae, which includes other livebearers such as platys, swordtails, guppies and mollies. They are found in fresh and brackish water. Of the 21 described Limia species, 17 are endemic to Hispaniola, one is found on both Hispaniola and Jamaica, and the Cayman Islands, Cuba, and Venezuela have an endemic species each. Limia are popular in aquaria among more advanced hobbyists.
Nannacara is a genus of small freshwater cichlid fish endemic to South America. The genus is part of the Cichlasomatini tribe of the Cichlasomatinae subfamily. In the aquarium hobby, the fish is considered a dwarf cichlid along with Apistogramma, Mikrogeophagus, and Dicrossus species. Nannacara anomala is the most commonly encountered species in the aquarium trade.
Colomesus asellus, the Amazon puffer, asellus puffer, South American freshwater puffer or Peruvian puffer is a species of pufferfish confined to the Amazon, Essequibo and Orinoco basins in tropical South America. It is a popular aquarium species.
Brachygobius is a small genus of gobies. They are popular aquarium fish where a number of species are sold as bumblebee gobies because their colours are similar to those of bumblebees.
Poeciliopsis is a genus of poeciliid fishes that primarily are native to Mexico and Central America. The only exceptions are P. turrubarensis where the range extends into Colombia, and P. occidentalis where the range extends into Arizona and New Mexico.
Heterandria is a genus of livebearing fishes within the family Poeciliidae. Most species occur in Guatemala and its surroundings, particularly Mexico, but the midget livebearer (H. formosa) comes from the southeastern United States.
Heterandria formosa is a species of livebearing fish within the family Poeciliidae. This is the same family that includes familiar aquarium fishes such as guppies and mollies. Heterandria formosa is not as commonly kept in aquaria as these species. Despite the common name "least killifish", it belongs to the family Poeciliidae and not to one of the killifish families. H. formosa is one of the smallest fish species; the 1991 Baensch Aquarium Atlas listed it as the 7th smallest fish in the world, and as of 2006 it remains the smallest fish species found in North America.
The redtail splitfin or redtail goodeid is a species of goodeid fish from the family Goodeidae and subfamily Goodeinae. Like other members of Goodeinae, the redtail splitfin is native to Mexico and a livebearer. However, the goodeid mating system differs in several ways from the more common livebearing fish from the family Poeciliidae that includes guppies and swordtails. While no goodeid species is a very popular aquarium fish, the redtail splitfin is one of the most popular. Only the male has the red-orange tail for which it is named. Its specific name honours the collector of the type, Gustav Eisen (1847–1940) who was Curator of Marine Invertebrates at the California Academy of Sciences in San Francisco, California.
The smallscale archerfish is a perciform fish of genus Toxotes. As its name suggests, the scales of the smallscale archerfish are smaller than those of other archerfish. They reach a maximum length of 15 centimetres (5.9 in). Smallscale archerfish live in the tropical Indo-Pacific region and are potamodromous, moving between fresh and brackish water through their lifetimes.
Epiplatys sexfasciatus or six-barred panchax is a species of fish in the family Aplocheilidae that can be found in West and Central Africa. The fish is a timid surface dwelling predator. The six-barred panchax is up to 10 cm (4 in) long and closely resembles Epiplatys longiventralis.
The pike topminnow, more commonly known as pike killifish and sometimes referred to as topminnow, is a species of poeciliid found from Mexico to Nicaragua. It has also been introduced to Florida, USA. It is the only known member of its genus. The pike topminnow was described in 1860 by Austrian ichthyologist Rudolf Kner, who gave the type locality as Belize, which is reflected in this species' specific name.
Zenarchopteridae, the viviparous halfbeaks, is a family in the order Beloniformes. The Zenarchopteridae exhibit strong sexual dimorphism, practicing internal fertilisation, and in some cases ovoviviparous or viviparous. The members in the family are mainly found in fresh and brackish water of tropical Asia and New Guinea, but the genus Zenarchopterus also includes marine species from the Indo-Pacific. Several, such as the wrestling halfbeak, have become commonly traded aquarium fish.
Poeciliinae is a subfamily of killifish from the family Poeciliidae which contains species from the Americas which are collectively known as the livebearers because many, but not all, of the species within the subfamily are ovoviviparous.
Butidae is a family of sleeper gobies in the order Gobiiformes. The family was formerly classified as a subfamily of the Eleotridae but the 5th Edition of Fishes of the World classifies it as a family in its own right. Molecular phylogenetic analyses have demonstrated that the Butidae are a sister clade to the clade containing the families Gobiidae and Gobionellidae and that the Eleotridae is a sister to both of these clades. This means that the Eloetridae as formerly classified was paraphyletic and that its subfamilies should be raised to the status of families.
The Cuban limia, also known as banded limia, Cuban molly, Cuban topminnow or tabai is a species of livebearing freshwater fish from the family Poeciliidae. The species is native to Cuba where it was endemic but it has been introduced to Hawaii.
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