30, Rue du Mont Ussy, 77300 Fontainebleau, France..
Zootaxa. 2021 Jan 20;4915(1):zootaxa.4915.1.10. doi: 10.11646/zootaxa.4915.1.10.
Nothobranchius elucens, new species, from a seasonal habitat in the Aringa system of the Achwa River in the upper Nile drainage in northern Uganda, is described. It belongs to the N. rubroreticulatus species group, whose members are characterised by male coloration of anal and caudal fins with slender light blue subdistal band and slender dark distal band. Nothobranchius elucens is distinguished from all other members of the genus by the following characters in males: body colouration golden-grey with brown scale margins creating irregular vertical stripes on trunk; anal fin yellow with brown spots proximally, with slender brown median band, followed by a slender light blue subdistal band and a slender black distal band; caudal fin brown proximally and medially, followed by a slender light blue subdistal band and a slender black distal band; dorsal fin golden with irregular brown stripes and narrow light blue subdistal band and with narrow black distal band. Furthermore, it differs from the closest known relative, N. taiti, also by the morphometric characters of having a smaller head length of 29.5-33.1 % SL; smaller prepectoral length of 31.2-33.9 % SL; greater head depth of 81-87 % HL; greater interorbital width of 43-49 % HL; and greater caudal peduncle length of 145-152 in % of its depth.
新物种小眼无须鱲，采自乌干达北部上尼罗河水系阿钦瓦河季节性生境。它属于小眼无须鱲的 N. rubroreticulatus 种团，该种团成员的雄鱼具有特征性的臀鳍和尾鳍颜色，由细的浅蓝色亚远端带和细的黑色远端带组成。小眼无须鱲与属内其他所有物种的区别在于雄鱼具有以下特征：体侧呈金黄色，带褐色缘的鳞片形成不规则的垂直条纹；臀鳍黄色，近端有褐色斑点，有细的褐色中央带，后面是细的浅蓝色亚远端带和细的黑色远端带；尾鳍近端和中部为褐色，后面是细的浅蓝色亚远端带和细的黑色远端带；背鳍金黄色，有不规则的褐色条纹，狭窄的浅蓝色亚远端带和狭窄的黑色远端带。此外，它与最接近的已知近亲 N. taiti 也有形态特征的区别，包括头长占标准体长的 29.5-33.1%；前躯长占标准体长的 31.2-33.9%；头高占标准体长的 81-87%；眼间距占标准体长的 43-49%；尾柄长占尾柄高的 145-152%。
