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| Telmatochromis salzburgeri Indermaur, Schedel & Ronco, 2024 |
Abstract
The lamprologine cichlid genus Telmatochromis was long considered primarily lacustrine and endemic to Lake Tanganyika until an undescribed Telmatochromis species was reported from the Lufubu River (Lake Tanganyika drainage, Zambia). A phylogenomic study in 2021 confirmed the association of Telmatochromis sp. “lufubu” with Telmatochromis along with another riverine species, Neolamprologus devosi (Malagarasi drainage, Tanzania). Here, we quantify the morphological diversity of the genus Telmatochromis and the two associated riverine species using a multivariate dataset combining geometric and classical morphometrics, as well as meristics. We identify three distinct morphological clusters: the “Telmatochromis vittatus complex” with highly elongated bodies and short heads, the “Telmatochromis temporalis complex” with deeper bodies, and the two riverine species with intermediate body elongation and large heads. Further, we formally describe the species endemic to the lower Lufubu River as Telmatochromis salzburgeri sp. nov. and reassign N. devosi to Telmatochromis. Telmatochromis devosi comb. nov. differs from all congeners by the absence of bi- and tricuspid teeth in the inner tooth rows of the oral dentition. T. salzburgeri sp. nov. can be distinguished from all other Telmatochromis species by a prominent orange stripe along the base of the dorsal fin and from T. devosi comb. nov. by the relatively smaller size of the lower pharyngeal jaw. Both riverine species differ from all lacustrine Telmatochromis by a lower number of dorsal-fin spines. Additionally, the riverine species can be distinguished from the T. vittatus complex by having larger heads and longer oral jaws, and from the T. temporalis complex by their lower relative body depth. With the inclusion of new riverine members, the genus Telmatochromis is revealed to be more morphologically and ecologically diverse than previously recognized.
Keywords: Africa, Cichlidae, Great Lakes, ichthyofauna, Lufubu River
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| Image series of Telmatochromis salzburgeri sp. nov. (a) Underwater pictures of T. salzburgeri sp. nov. (from top to bottom): a dark specimen, a light specimen, a juvenile, and together with the riverine haplochromine Orthochromis indermauri (images by A.I. and F.D.B.S.). (b) Photograph of a paratype (NMB-6478, ex. UNIBAS-IC-USH1) in light colouration (top image) and the dark holotype (NHB-6475, ex. UNIBAS-IC-USG9), both taken at the field site from living individuals. The lower two images show the preserved holotype and its X-ray radiograph (images by A.I., F.D.B.S., and Aurelia Wolf). (c) Images of the lower pharyngeal jaw of a paratype (ZSM-PIS-044282-DRC-3147) based on a computed tomography (CT) scan (images by F.R.). |
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| Overview of the lamprologine cichlid genus Telmatochromis from Lake Tanganyika and the two riverine taxa: Neolamprologus devosi and Telmatochromis sp. “lufubu”. |
Telmatochromis devosi comb. nov.
reassign Neolamprologus devosi to Telmatochromis.
Telmatochromis salzburgeri sp. nov.
= Telmatochromis sp. “lufubu”
Differential diagnosis: Adult individuals of T. salzburgeri sp. nov. are distinguished from all other members of the genus Telmatochromis by the presence of a prominent orange stripe along the base of the dorsal fin, extending into the dorsal fin and over the dorsum (see Figure 5a,b). Additionally, T. salzburgeri sp. nov. differs from members of the T. vittatus complex (i.e., T. bifrenatus, T. brichardi, T. vittatus, and allies such as Telmatochromis sp. “longola”) and T. brachygnathus by having a larger head (26.96–30.08 vs. 20.4–26.65 HL%SL) and longer jaws (29.18–40.68 vs. ...
Etymology: The species is named in honor of our friend, colleague, and mentor Prof. Dr. Walter Salzburger for his contributions in advancing the field of evolutionary biology and, in particular, cichlid research in Lake Tanganyika. He has supported several projects and numerous field expeditions of all the authors with great enthusiasm, which led, among many other things, to the description of T. salzburgeri sp. nov.
Adrian Indermaur, Frederic D. B. Schedel, Fabrizia Ronco. 2024. Morphological Diversity of the Genus Telmatochromis from the Lake Tanganyika Drainage with the Description of A New riverine Species and the Generic Reassignment of the Malagarasi River lamprologine. Journal of Fish Biology. DOI: doi.org/10.1111/jfb.16042
