Staff directory
Emmanuel Vreven
Biology
Vertebrates
Vertebrates
Publication details
Bragança, P.H.N, van der Zee, J.R., Sonnenberg, R. & Vreven, E. 2021. ‘Description of two new miniature species of Hylopanchax Poll & Lambert, 1965 (Cyprinodontiformes: Procatopodidae),from northeastern Gabon, with an updated diagnosis of the genus based on morphology, colouration and osteology’. Journal of Fish Biology 98: 655–667. Wiley Online Library. DOI: 10.1111/jfb.14606. (PR).
Article in a scientific Journal / Article in a Journal
Two new species of the lampeye genus Hylopanchax are described from the Ivindo
River basin in the Ogowe River drainage. Hylopanchax multisquamatus, new species,
and Hylopanchax thysi, new species, differ from congeners by the presence of a hyaline
urogenital male papilla with small black spots and a dark-brown reticulate pattern
on the flanks of both males and females in preserved specimens. Hylopanchax multisquamatus
is distinguished from congeners by the number of scales on the midlongitudinal
series (27–30 vs. 19–26, respectively) and by the relative anterior/posterior
flank scale depth ratio (140%–150% vs. 170%–220%). Hylopanchax thysi is distinguished
from all other congeners, except Hylopanchax paucisquamatus, by the
presence of vertebrae (30 vs. 31–33) and is further distinguished from
H. multisquamatus by the presence of a deeper caudal peduncle and much larger
anterior flank scales. It is distinguished from H. paucisquamatus by the presence of a
hyaline urogenital male papilla with small black spots and a dark-brown reticulate pattern
on the flanks of both males and females in preserved specimens. Osteological
data of Hylopanchax are presented for the first time, and an updated diagnosis based
on external morphology, colouration pattern and osteology is provided. An osteological
comparison with closely related species belonging to the genera Procatopus,
Hypsopanchax and “Hypsopanchax” is presented. (a) A truncate and slightly
downward-directed anterior process of the angulo-articular and (b) a guitar-shaped
lachrymal with both its anterior and posterior margins sharply curved are here considered
as diagnostic features of Hylopanchax.