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| Parauchenoglanis stiassnyae Modimo, Bernt, Monsembula Iyaba, Mbimbi & Liyandja, 2024 DOI: 10.1111/jfb.15885 |
Abstract
A new, distinctively short-bodied giraffe catfish of Parauchenoglanis is described from the Ndzaa River, a small left-bank tributary of the Mfimi-Lukenie basin in the Central basin of the Congo River in the Democratic Republic of the Congo. The new species can be distinguished from all congeners by having 29 or fewer (vs. 33 or more) total vertebrae. It can further be distinguished from all congeners, except Parauchenoglanis zebratus Sithole et al., 2023 and Parauchenoglanis ngamensis (Boulenger 1911), by having 13 or 14 (vs. 16 or more) pre-anal vertebrae. The species is endemic to the Mfimi River basin, where it has been collected mainly in blackwater tributaries.
Keywords: Congo basin, CT scan, DNA barcoding, morpholog,y Ndzaa River, Parauchenoglanis
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| Parauchenoglanis stiassnyae sp. nov. Photographs of preserved (a) holotype (AMNH 278139 in lateral view) and (b–d) paratype (AMNH 278165, 68.1 mm standard length [SL], respectively, in dorsal, lateral, and ventral views). Scale bar: 1 cm. |
Parauchenoglanis stiassnyae, sp. nov.
Diagnosis: P. stiassnyae is distinguished from all congeners by having 28–29 vertebrae (vs. 33 or more). P. stiassnyae is also distinguished from all congeners by the possession of 13–14 pre-anal vertebrae (vs. 15 or more) except for Parauchenoglanis zebratus (14–17) and Parauchenoglanis ngamensis (13, holotype). The new species can further be distinguished from P. cf. punctatus_L3, P. balayi, P. longiceps, P. pantherinus, P. punctatus, and P. ubangensis by a narrower supraoccipital process–nuchal plate interdistance (1.4%–2.9% vs. >3% HL); from P. cf. punctatus_L3, P. guttatus, P. longiceps, P. pantherinus, and P. punctatus by a wider orbital HW (64.7%–76.2% vs. 54.9%–63.9% HL); from P. guttatus, P. longiceps, and P. ubangensis by a wider mouth (37.8%–50.8% vs. 25.9%–35.7% HL); from P. guttatus, P. punctatus, P. ubangensis, and P. zebratus by a wider premaxillary toothplate (12.9%–18.6% vs. 6.6%–12.5% HL); from P. guttatus, P. longiceps, P. pantherinus, and P. zebratus by a wider head (HW: 70.1%–81.1% vs. 58.9%–69.3% HL); from P. balayi and P. pantherinus by a shorter dorsal-fin spine (10.8%–16% vs. 16.1%–18.8% SL); from P. guttatus and P. pantherinus by a smaller orbital diameter (9.5%–14.2% vs. 14.4%–16.9% HL) and a wider interpectoral distance (16.7%–21.4% vs. 15.3%–16.6% SL); from P. balayi, P. ngamensis (holotype), and P. ubangensis by a shorter adipose-fin–caudal-fin interdistance (2.7%–5.2% vs. 6.2%–10.5% SL); and from P. balayi by a longer head (HL: 31.3%–35% vs. 28.1%–30.6% SL) and a narrower interorbital (IOD: 19.5%–27.1% vs. 27.3%–28% HL).
Biology and ecology: Most specimens of P. stiassnyae were collected in forested habitats over mud and plant debris in tributaries of the Mfimi River. The rivers where specimens of P. stiassnyae have been collected are characterized by a humic, moderately acidic (pH 4.1–5.3), and dark-brown water with low conductivity (10–50 μS/cm) and low concentrations of dissolved solids (TDS: 10–30 mg/L). These observations, combined with the species body colouration, suggest that P. stiassnyae is adapted to forested habitats, muddy, humic, and dark-brown waters of the Mfimi River tributaries.
Etymology: P. stiassnyae is named after Melanie L. J. Stiassny (MLJS) of the AMHN. MLJS is the initiator of the AMNH Congo Project that resulted in significant documentation and an improved systematic, biological, and evolutionary understanding of the Congo River basin ichthyofauna with an extensive collection deposited at the AMNH, the University of Kinshasa, and the University of Marien Ngouabi. Additionally, MLJS trained and continues to train numerous Congolese ichthyologists, including the authors of the present paper. We dedicate this species to her outstanding work and commitment to biodiscovery and conservation in the Congo River basin.
Myriam Y. Modimo, Maxwell J. Bernt, Raoul J. C. Monsembula Iyaba, José J. M. M. Mbimbi and Tobit L. D. Liyandja. 2024. Parauchenoglanis stiassnyae (Siluriformes: Auchenoglanididae): A New Species of Giraffe Catfish from Mfimi-Lukenie Basin, central Africa, Democratic Republic of Congo. Journal of Fish Biology. DOI: doi.org/10.1111/jfb.15885
