Aenigmachanna is a genus of ray-finned fish in the order Ananbantiformes. It is the only genus in the family Aenigmachannidae, or dragon snakeheads. It contains two species, both of which are largely restricted to subterranean habitats in southwestern India, namely in the Western Ghats foothills in the state of Kerala.[1][2]
| Aenigmachanna | |
|---|---|
| |
| Aenigmachanna gollum | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Clade: | Percomorpha |
| Order: | Anabantiformes |
| Suborder: | Channoidei |
| Family: | Aenigmachannidae Britz, Dahanukar, Anoop, Philip, Clark, Raghavan & Rüber, 2020 |
| Genus: | Aenigmachanna Britz, Anoop, Dahanukar and Raghavan, 2019 |
| Type species | |
| Aenigmachanna gollum Britz, Anoop, Dahanukar & Raghavan, 2019
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| Species | |
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2, see text. | |
Both of the species in this genus display a unique array of traits that distinguish them from their closest living relatives, the true snakeheads in the family Channidae. These include a much longer and more slender body, numerous scales, a very long anal fin, and a lack of ability to maintain buoyancy. Molecular analyses indicate that they split off from Channidae around 34 or 109 MYA. This may indicate that Aenigmachannidae is a uniquely Gondwanan lineage, and if the higher end of estimations is correct, it may have survived the breakup of the Gondwanan supercontinent around 120 MYA.[1][3]
They are unique among cavefish for being one of the few cave-dwelling members of the large clade Percomorpha. Despite their habitat, they physically display little troglomorphism aside from a slightly reduced pigmentation, indicating that they either colonized the caves relatively recently or that they are subtroglophiles that mostly live underground, but depend on aboveground habitats for some functions. Due to their restricted habitat and unique nature, both are considered relict species.[3][4][5]
Taxonomy
editSpecies
edit- Aenigmachanna gollum Britz, Anoop, Dahanukar and Raghavan, 2019 (Gollum snakehead)
- Aenigmachanna mahabali Kumar, Basheer, and Ravi, 2019 (Mahabali snakehead)
The genus was initially described in early 2019 to serve as a monotypic genus for A. gollum, the first species to be described in the genus. Later in the year, A. mahabali was described as a distinct species, indicating that there were indeed multiple species in the genus.[3][5]
References
edit- ^ a b Britz, Ralf; Dahanukar, Neelesh; Anoop, V. K.; Philip, Siby; Clark, Brett; Raghavan, Rajeev; Rüber, Lukas (30 September 2020). "Aenigmachannidae, a new family of snakehead fishes (Teleostei: Channoidei) from subterranean waters of South India". Scientific Reports. 10 (1): 16081. Bibcode:2020NatSR..1016081B. doi:10.1038/s41598-020-73129-6. ISSN 2045-2322. PMC 7527459. PMID 32999397.
- ^ Main, Douglas (19 October 2020). "Dragon snakeheads—strange new underground fish—discovered in India". National Geographic. Archived from the original on 20 October 2020.
- ^ a b c Raghavan, Rajeev; Dahanukar, Neelesh; Anoop, V. K.; Britz, Ralf (9 May 2019). "The subterranean Aenigmachanna gollum, a new genus and species of snakehead (Teleostei: Channidae) from Kerala, South India". Zootaxa. 4603 (2): 377–388. doi:10.11646/zootaxa.4603.2.10. ISSN 1175-5334. PMID 31717234. S2CID 164781147.
- ^ "New species of subterranean fish named after The Lord of the Rings character". www.nhm.ac.uk. Retrieved 9 May 2019.
- ^ a b Ravi, Charan; Basheer, V. S.; Kumar, Rahul G. (17 July 2019). "Aenigmachanna mahabali, a new species of troglophilic snakehead (Pisces: Channidae) from Kerala, India". Zootaxa. 4638 (3): 410–418. doi:10.11646/zootaxa.4638.3.6. ISSN 1175-5334. PMID 31712470. S2CID 203899040.