\[ **BT: [[chordates]]** ] --- # ray-finned fish Ray-finned fish, or actinopterygians, are members of the class **Actinopterygii**.[^1] ## classification of ray-finned fish ### Salmoniformes (Order) #### Salmonidae (Family) ##### *Oncorhynchus* (Genus) ###### *Oncorhynchus mykiss* (rainbow trout) [[Rainbow trout (Oncorhynchus mykiss) exhibit alternative reproductive phenotypes with a large inversion that mediates a trade-off between early maturation and later fecundity.]][^2] - see also: [[genetics#polymorphism|polymorphism]] [^1]: ‘Actinopterygii’, Wikipedia, last edited 25 February 2026, 12:39 (UTC), <https://en.wikipedia.org/wiki/Actinopterygii>. [^2]: Donna L. Maney et al., ‘[[Maney et al. ‘Inside the Supergene of the Bird with Four Sexes’, 2020|Inside the Supergene of the Bird with Four Sexes]]’, *Hormones and Behavior*, vol. 126 (September 2020), p. 14, <https://doi.org/10.1016/j.yhbeh.2020.104850>.