Paedocypris
| Paedocypris | ||||||||||||
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Paedocypris progenetica |
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Paedocyprididae | ||||||||||||
| Mayden & Chen , 2010 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Paedocypris | ||||||||||||
| Kottelat , Britz , Tan & Witte , 2005 |
Paedocypris is a genus of very small freshwater fish from the order of the carp-like . It consists of three types. The females of a species of the genus, Paedocypris progenetica, are the smallest known fish worldwide with a length of 7.9 mm and, after the frog Paedophryne amauensis (7.7 mm), the smallest known vertebrates . The genus occurs in tropical Southeast Asia on the Malay Peninsula , Sumatra and Borneo .
features
Paedocypris species grow to be 7.9 to 10.15 mm long. The animals are pedomorphic . This means that despite sexual maturity they show many characteristics of a larval stage . The fish are almost transparent and there is no bony skull roof . A Weber apparatus is available. Paedocypris not only have hemostrils on the tail vertebrae like other carp fish, but they start with the seventh to twelfth vertebra. The fangs are three-pointed. The fin fringe on the underside of the caudal fin stalk , which is present in many carp fish larvae, is also present in Paedocypris in the adult stage .
The outermost pelvic ray of the males is heavily modified, flattened and covered with keratinized skin. The tip of the uppermost fin ray has a small, outwardly directed hump-like outgrowth of horny skin. The pulling away and the leading muscle of the pelvic fins are particularly well developed in the males. The males have a small field of horny skin in front of the pelvic fins. Your genital opening is enlarged and forms a pocket around the first two to three rays of the anal fin.
Systematics
The genus Paedocypris was introduced in 2005 by the Swiss ichthyologist Maurice Kottelat and three colleagues. Paedocypris is a representative of the carp-like (Cypriniformes), but its position within the order is not yet fully established. According to analyzes of cytochrome B nucleotide sequences , it belongs to the carp family (Cyprinidae) and there in the subfamily of danioninae , where it occupies a basal position together with the also dwarf genus Sundadanio . An analysis of the Cypriniformes based on six cell nucleus genes, however, revealed a sister group relationship for Paedocypris to all other representatives of the Cypriniformes without a closer relationship to Sundadanio , which justifies the classification into an independent family (Paedocyprididae). At Stout and colleagues, Paedocypris is the sister group of all other carp fish-like (Cyprinoidei). In the Fishbase database the genus is assigned to the Danioninae, in the Catalog of Fishes, which is updated monthly, it forms the family Paedocyprididae, which was named after Paedocypris .
species
To date, three types have been described:
- Paedocypris micromegethes Kottelat, Britz, Tan & Witte, 2006
- Paedocypris progenetica Kottelat, Britz, Tan & Witte, 2006
- Paedocypris carbunculus Britz & Kottelat, 2008
literature
- M. Kottelat, R. Britz, HH Tan, K.-E. Witte 2005: Paedocypris, a new genus of Southeast Asian cyprinid fish with a remarkable sexual dimorphism, comprises the world's smallest vertebrate. Proceedings of the Royal Society, Volume 273, Number 1589 / April 22, 2006, doi : 10.1098 / rspb.2005.3419 .
Individual evidence
- ↑ Lukas Rüber, Maurice Kottelat , Heok Hui Tan, Peter KL Ng, Ralf Britz: Evolution of miniaturization and the phylogenetic position of Paedocypris, comprising the world's smallest vertebrate. BMC Evolutionary Biology (2007), Volume: 7, Issue: 38, Publisher: BioMed Central, Pages: 38 doi : 10.1186 / 1471-2148-7-38
- ↑ Richard L. Mayden, Wei-Jen Chen: The world's smallest vertebrate species of the genus Paedocypris: A new family of freshwater fishes and the sister group to the world's most diverse clade of freshwater fishes (Teleostei: Cypriniformes). Molecular Phylogenetics and Evolution 57 (2010): pp. 152-175
- ↑ Stout, CC, Tan, M., Lemmon, AR, Moriarty Lemmon, E. & Armbruster, JW (2016): Resolving Cypriniformes relationships using an anchored enrichment approach. BMC Evolutionary Biology, November 2016. DOI: 10.1186 / s12862-016-0819-5
- ↑ a b Paedocypris on Fishbase.org (English)
- ↑ Paedocypris in the Catalog of Fishes (English)