Two new species of African suckermouth catfishes, genus Chiloglanis (Siluriformes: Mochokidae), from Kenya with remarks on other taxa from the area

These species inhabit most tropical rivers throughout sub-Saharan Africa and the Nile River basin. Chiloglanis species possess distinctive oral discs that allow them to feed and maintain their position in flowing waters. Recent expeditions in Kenya and examination of existing collections confirmed the presence of two undescribed Chiloglanis species and revealed previously unknown diversity within the Athi River system. The two new species are easily distinguished from described congeners in the area by external morphology, allopatric distributions, and genetic markers. Chiloglanis kerioensis sp. nov. is restricted to the Kerio River system and is the only known suckermouth catfish from the Lake Turkana basin. Chiloglanis devosi sp. nov. is known only from the type locality, the Northern Ewaso Nyiro (Ng'iro) below Chanler's Falls. Morphological analysis of the Kenyan Chiloglanis species was conducted using principal components analysis (PCA) of the residuals from 45 morphometric measurements regressed against standard length from 169 specimens. The PCA distinguished the three previously known Chiloglanis species and the two new species described herein. The groups revealed by the PCA correspond to those discovered in previous phylogenetic analysis. Principal component (PC) 1 accounts for 19.2% of overall variation, with oral disc length, prepectoral length, and dorsal spine length contributing most to the variation observed along PC1. Chiloglanis kerioensis sp. nov. is a small, relatively deep-bodied species with a maximum standard length of 40.3 mm. The species is distinguished from other Chiloglanis species by its fewer mandibular teeth, larger orbit, longer barbels, and arrangement of the mandibular teeth. The species is also distinguished from Chiloglanis deckenii by its longer premaxillary tooth pad and longer lower lip. The species is further distinguished from Chiloglanis sp. aff. deckenii by its longer postcleithral process and longer lateral mandibular barbels. The undescribed Chiloglanis sp. occurring sympatrically with Chiloglanis brevibarbis in the Tsavo River is morphologically similar to C. brevibarbis, but the morphology of the oral disc and mouth parts are closer to C. deckenii. This species is currently referred to as Chiloglanis sp. aff. deckenii. The species is distinguished from C. brevibarbis by its body measurements, which ally it with C. brevibarbis, but the morphology of the oral disc and mouth parts are closer to C. deckenii.