(Britz et al. 2020; Fig. 1) is a newly discovered dragon snakehead, a small (12cm) extant cave fish from India. In the large reptile tree (LRT, 1755+ taxa) Aenigmachanna nests with the much larger snakehead, Channa (Figs. 2, 3).
The odd cheekbone of Aenigmachanna
(bright green) is a unique sort of maxilla with twin dorsal processes. No LRT ancestors have such a cheekbone until we get back to the equally vicious pirhana (Serrasalmus) and its longer, lower sister, the South American gold wolf fish (Hoplerythrinus), but those cheekbones are typical extensions of the jugal.
Channa sp. (Scopoli 1777; 25 cm to 1+m) is the extant snakehead, a predatory freshwater fish nesting here between the pupfish (Pseudorestias) and the wolffish (Anarhichas). Channa can breathe air and travel across land for short distances seeking new ponds, but this is rare as the pectoral fins are weak and poorly angled for this. Like the wolffish, the dorsal and anal fins are long. The pelvic fins are also absent. Teeth are present on the parasphenoid. In Channa the maxilla is a toothless splint.
Early Eocene fossils are known from this clade.
Snakehead nicknames include “Frankenfish” and “the fish from Hell”.
Aenigmachanna helped inform and repair
skull bone identities in Channa. The large open cheek area behind the eye in both taxa is filled with jaw muscles, apparently necessary for such large teeth.
Britz et al. 2020. Aenigmachannidae, a new family of snakehead fishes (Teleostei: Channoidei) from subterranean waters of South India. Nature.com/scientificreports 10:16081. https://doi.org/10.1038/s41598-020-73129-6
Scopoli JA 1777. Introdvctio ad historiam natvralem sistens genera lapidvm, plantarvm, et animalivm hactenvs detecta, caracteribvs essentialibvs donata, in tribvs divisa, svbinde ad leges natvrae. – pp. [1-9], 3-506, [1-34]. Pragæ. (Gerle).
More pix and taxon distribution info here.