''Scleropages'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Osteoglossidae Osteoglossidae is a family of large freshwater fish, which includes the arowanas and arapaima. The family contains two subfamilies Arapaiminae and Osteoglossinae, with a total of five living genera. Osteoglossids are basal teleosts that origin ...

found in

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...

and Australia. All of these species are

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other ...

and have great jumping ability. These

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

are highly valued as aquarium fish, particularly by those from Asian cultures. In 2003, a study redescribed several naturally occurring color varieties of ''S. formosus'' into four separate species. The majority of researchers dispute these redescriptions, arguing that the published data are insufficient to justify recognizing more than one Southeast Asian species of ''Scleropages'' and that divergent haplotypes used to distinguish the color strains into isolated species were found within a single color strain, contradicting the findings. They are considered

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

, consisting of closely related

haplotypes A haplotype ( haploid genotype) is a group of alleles in an organism that are inherited together from a single parent. Many organisms contain genetic material ( DNA) which is inherited from two parents. Normally these organisms have their DNA or ...

based on color. The ancestor of the Australian arowanas: ''S. jardinii'' and ''S. leichardti'', diverged from the ancestor of the Asian arowanas about 140 million years ago, during the

Early Cretaceous The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pr ...

period. The morphological similarity of all seven species shows that little evolutionary change has taken place recently for these ancient fish. The genus had a much wider

distribution Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

during the early

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...

, with

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

remains known from the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

Niger ) , official_languages = , languages_type = National languagesBelgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to ...

,Taverne, L. (2009): On the presence of the osteoglossid genus ''Scleropages'' in the Paleocene of Niger, Africa (Teleostei, Osteoglossomorpha). ''Bulletin de l'Institut royal des Sciences naturelles de Belgique, Science de la Terre, 79: 161-167.'' and from the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

of China.

Species

There are currently 7 recognized species in this genus:

Phylogeny

Phylogeny based on the work of Pouyaud, Sudarto & Teugels 2003.

References

{{Taxonbar, from=Q1766674 Freshwater fish genera Taxa named by Albert Günther