Wednesday, October 25, 2023

[Ichthyology • 2023] Labeo mbimbii & L. manasseeae • Two New Labeo (Cypriniformes: Cyprinidae: Labeoninae) Endemic to the Lulua River in the Democratic Republic of Congo (Kasai Ecoregion); a Hotspot of Fish Diversity in the Congo Basin


 Labeo mbimbii L. manasseeae
 Liyandja & Stiassny, 2023


Abstract 
Labeo mbimbii, n. sp., and Labeo manasseeae, n. sp., two small-bodied Labeo species, are described from the lower and middle reaches of the Lulua River (Kasai ecoregion, Congo basin) in the Democratic Republic of Congo. The two new species are members of the L. forskalii species group and are genetically distinct from all other species of that clade. Morphologically they can be distinguished from central African L. forskalii group congeners except L. dhonti, L. lukulae, L. luluae, L. parvus, L. quadribarbis, and L. simpsoni in the possession of 29 or fewer (vs. 30 or more) vertebrae and from those congeners by a wider interpectoral, among other features.

The two new species are endemic to the Lulua River and, although overlapping in geographical range and most meristic and morphometric measures, are readily differentiated by differing numbers of fully developed supraneural bones, predorsal vertebrae, snout morphology, and additional osteological features. The description of these two species brings the total of Labeo species endemic to the Lulua basin to three. The third endemic species, L. luluae, was previously known only from the juvenile holotype, but numerous additional specimens have now been identified. The cooccurrence of 14 Labeo species in the Lulua River, three of which are endemic, highlights this system as a hotspot of Labeo diversity in the Congo basin and across the continent.

Keywords: Labeo mbimbiiLabeo manasseeaeLabeo, Classification, Cyprinida, Congo (Democratic Republic), Congo, Classification, Fishes

 Labeo mbimbii, n. sp. Holotype (AMNH 277862, AMCC 249232): 
A. lateral view, immediately postmortem; B. in preservation, lateral view; C. ventral view; and D. dorsal view. Scale bar = 1 cm.
 Labeo manasseeae, n. sp. Holotype (AMNH 269110, AMCC 249240):
A. immediately postmortem; B. in preservation, lateral view; C. ventral view; and D. dorsal view. Scale bar = 1 cm

Labeo mbimbii, n. sp.
Labeo manasseeae, n. sp.


Tobit L.D. Liyandja and Melanie L.J. Stiassny. 2023. Description of Two New Labeo (Labeoninae; Cyprinidae) Endemic to the Lulua River in the Democratic Republic of Congo (Kasai Ecoregion); a Hotspot of Fish Diversity in the Congo Basin. American Museum Novitates. (3999); 1-22. DOI: 10.1206/3999.1 URI: hdl.handle.net/2246/7321