Danionella is a genus of danionin fish found in freshwater habitats in Myanmar and West Bengal, India. It includes some of the smallest fishes.
| Danionella | |
|---|---|
.jpg)
| |
| Danionella priapus | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Cypriniformes |
| Family: | Cyprinidae |
| Subfamily: | Danioninae |
| Genus: | Danionella T. R. Roberts, 1986 |
| Type species | |
| Danionella translucida T. R. Roberts, 1986
| |
| Species | |
|
See text | |
Distribution
editFour out of Five Described species of Danionella are found in Myanmar. D. translucida is described from the Ayeyarwady River basin, and D. mirifica was described from the Kamaing area in upper Myanmar.[1] Danionella priapus is endemic to India.[2]
Description
editWhen first described, Danionella translucida was the smallest ostariophysan and the smallest adult vertebrate to inhabit fresh water.[3] Its adult size ranges from 10–12 millimetres (.43–.47 in) SL.[3] D. mirifica gets slightly larger, at about 14 mm (.55 in) SL, but is still one of the smallest freshwater fishes.[1][4]
Danionella species lack scales and barbels, [3] but possess a lateral line.[5]
D. mirifica has a single row of melanophores between the pelvic fins and the tips of the cleithra, and there is a lack of melanophores on the underside of the abdomen.[1]
D. dracula reaches 17 mm in length. It is neotonous, lacking 44 bones that develop late in the related zebrafish Danio rerio. They have teeth made of bone, rather than the true teeth of other fishes, and the males have a pair of boney fangs which may be used during male-male competitions over nesting sites. Britz et al. believe the lineage lost true teeth about 50 Ma.[6]
Species
edit| Species | Common Name | Image |
|---|---|---|
| Danionella cerebrum Britz, Conway & Rüber, 2021 | .jpg)
| |
| Danionella dracula Britz, Conway & Rüber, 2009 | Dracula fish | |
| Danionella mirifica Britz, 2003 | ||
| Danionella priapus Britz, 2009 |
| |
| Danionella translucida T. R. Roberts, 1986 | 
|
References
edit- ^ a b c Britz, Ralf (October 2003). "Danionella mirifica, a new species of miniature fish from Upper Myanmar (Ostariophysi: Cyprinidae)" (PDF). Ichthyol. Explor. Freshwaters. 14 (3): 217–222. Retrieved 2009-06-24.
- ^ Britz, Ralf (October 2009). "Danionella Priapus, a New Species of Miniature Cyprinid Fish from West Bengal, India (Teleostei: Cypriniformes: Cyprinidae)".
- ^ a b c Roberts, Tyson R. (1986). "Danionella translucida, a new genus and species of cyprinid fish from Burma, one of the smallest living vertebrates". Environmental Biology of Fishes. 16 (4): 231–241. doi:10.1007/BF00842977.
- ^ Froese, Rainer; Pauly, Daniel (eds.). "Danionella mirifica". FishBase. August 2011 version.
- ^ Hu, Yinan; Mauri, Angela; Donahue, Joan; Singh, Rajendra; Acosta, Benjamin; McMenamin, Sarah (2019). "Thyroid hormone coordinates developmental trajectories but does not underlie developmental truncation in danionins". Developmental Dynamics. 248 (11): 1144–1154. doi:10.1002/dvdy.76. ISSN 1097-0177. PMC 6824966. PMID 31228301.
- ^ Ralf Britz et al., Royal Society's journal Proceedings B, March 2009
- "Several other as yet unnamed Danionella species have very recently been discovered". Archived from the original on 2007-07-08.