Figure 3. A : PCAs of sympatric pairs of generalized vs.
thick-lipped ecomorphs of Labeobarbus spp. that live
sympatrically in each of six rivers: Birbir, Blue Nile, Didessa, Genale,
Gojeb, and Sore. B : Food spectra (IR: the index of relative
importance) of the sympatric ecomorphs (G – generalized, L –
thick-lipped) of the Labeobarbus spp. from the Blue Nile,
Didessa, Genale, and Gojeb.
The thick-lipped ecomorph was characterized by greatly developed middle
lobes on the lower lip (MLL) that was significantly longer compared to
the generalized ecomorph in all studied rivers (Supplementary Figure
S3). Individual MLL values varied from 10 to 33% in the thick-lipped
ecomorph (averaging – 21%) while in the generalized ecomorph they were
much lower – from 4 to 16% (averaging – 9%). Largest MLL values
within thick-lipped ecomorph were detected in the Birbir River (27%)
while the smallest one – in the Sore River (16%) and Blue Nile River
(16%).
Gut Length. The guts of thick-lipped ecomorph were shorter than
in generalized ecomorph from all studied rivers, sometimes significantly
(Supplementary Figure S3). The gut length of thick-lipped ecomorph
varied from 140.0 to 507.8% SL, averaging – 305.1%. The gut length of
generalized ecomorph varied from 157.2 to 646.1%, averaging – 332.9%.
Significant differences between sympatric thick-lipped and generalized
ecomorphs were detected in the Blue Nile (p<0.01), Genale
(p<0.05) and Gojeb (p<0.01) (Wilcoxon test).