[Ichthyology • 2024] Parauchenoglanis dolichorhinus, P. megalasma, P. poikilos, ... • Nine in One: Integrative Taxonomic Evidence of Hidden Species Diversity in the widespread Zambezi Grunter, Parauchenoglanis ngamensis (Siluriformes: Auchenoglanididae), from southern and south-central Africa

Parauchenoglanis spp. 

Sithole, Vreven, Bragança, Musschoot & Chakona, 2024 

 

DOI: doi.org/10.1093/zoolinnean/zlae121

 saiab.AC.za 

Abstract

The Zambezi grunter, Parauchenoglanis ngamensis, is currently distributed across four (sub)basins in southern and south-central Africa, namely the Okavango, upper Zambezi, Kwanza, and Kasai. The present study used a combination of molecular (barcoding), colour pattern, and other morphological data to explore the possible existence of hidden species diversity within this species. Based on the available samples, analyses of molecular data uncovered seven well-supported (.96–1.00 Bayesian posterior probabilities) candidate species, with 1.6%−8.5% genetic divergence between them. These, in addition to two more candidate species without genetic data, exhibited a combination of consistent colour pattern and other morphological differences that supported their distinction. The present study redescribes P. ngamensis, which is confined to the Okavango and upper Zambezi (sub)basins, and describes eight new species: two from the Kwanza Basin and six from the Kasai sub-basin. The fact that some of the species occur allopatrically, whereas others are sympatric and even syntopic indicates the complex palaeogeographical history of these basins. In addition, the high species diversity discovered in the Kasai sub-basin seems to be related to its highly peculiar hydrography. Accurate delimitation of species boundaries and mapping of their distribution is crucial for conservation assessments and guiding their protection.

allopatric speciation, barcoding, catfish, colour pattern, conservation

A. Parauchenoglanis patersoni

This species is named in honour of Dr. Angus Paterson, who was the Managing Director of the NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB) the time this paper was accepted. The name acknowledges Dr. Paterson’s dedication to developing taxonomic expertise and advancing ichthyological research in the poorly explored regions of southern Africa.

B. Parauchenoglanis ernstswartzi

This species is named in honour of Dr. Ernst Swartz, recognising his significant contributions to ichthyology, including the collection of specimens used in this study. Dr. Swartz’s pioneering exploration of the Kwanza and Kasai basins was instrumental in the discovery of several new species.

C. Parauchenoglanis dolichorhinus

The name ‘dolichorhinus’ is derived from the Greek words “dolichos” meaning “long,” and “rhinus” meaning “snout”. This name refers to the notably long snout of this species compared to others in the P. ngamensis group.

D. Parauchenoglanis poikilos

The name of this species is derived from the Greek adjective “poikilos,” which means “spotted”. The numerous distinctive spots along its body are a key characteristic of its identification.

E. Parauchenoglanis megalasma

The name of this species is derived from the Greek words “mega” meaning “large,” and “melasma” meaning “black spot”. It refers to the prominent, large black blotches along its lateral line.

G. Parauchenoglanis lueleensis

The suffix “-ensis” means “lives in” and refers to the Luele River in the Kasai sub-basin, where this species is found.

H. Parauchenoglanis luendaensis

Named after the Luenda River in the Kasai sub-basin, this species also carries the suffix “-ensis,” indicating the region it inhabits.

I. Parauchenoglanis chiumbeensis

This species is named after the Chiumbe River, which is also located in the Kasai sub-basin. The name acknowledges the region as the habitat of this newly identified species.

Yonela Sithole, Emmanuel J W M N Vreven, Pedro H N Bragança, Tobias Musschoot, Albert Chakona. 2024. Nine in One: Integrative Taxonomic Evidence of Hidden Species Diversity in the widespread Zambezi Grunter, Parauchenoglanis ngamensis (Siluriformes: Auchenoglanididae), from southern and south-central Africa. Zoological Journal of the Linnean Society. 202(3); zlae121. DOI: doi.org/10.1093/zoolinnean/zlae121 saiab.AC.za

Unveiling New Species: How Eight New Catfish Species Were Named

  saiab.AC.za/unveiling-new-species-how-eight-new-catfish-species-were-named/

 

[Ichthyology • 2024] Parauchenoglanis stiassnyae (Siluriformes: Auchenoglanididae) • A New Species of Giraffe Catfish from Mfimi-Lukenie Basin, central Africa, Democratic Republic of Congo

 

  Parauchenoglanis stiassnyae

Modimo, Bernt, Monsembula Iyaba, Mbimbi & Liyandja, 2024

DOI: 10.1111/jfb.15885

 x.com/MJBernt

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

  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

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