108 
DISCUSSION 
Including Schismatorhynchos endecarhapis and S. holorhynchos in 
the genus Schismatorhynchos raises a number of theoretical and 
practical problems, as would including them in the obvious alternat- 
ive, Lobocheilos. Bleeker’s (1863) diagnosis of Schismatorhynchos 
includes, among other things, mention of a deep, transverse cleft of 
the snout and the upper and lower lips not continuous around the 
corner of the mouth. Weber & de Beaufort (1916; Fig. 86) described 
an additional oro-labial structure of Schismatorhynchos, a frenulum 
between the lateral lobe of the lower lip and the isthmus (Fig. 2A). 
Hindsight shows that the cleft snout is characteristic, so far as is 
known, of a single species (S$. hetero-rhynchos) while the oro-labial 
features are found in at least two additional species. Our decision to 
include the new species in Schismatorhynchos rests on these oro- 
labial features, which we consider derived for Southeast Asian 
labeonins (we recognise them as synapomorphies of the genus 
Schismatorhynchos). 
The problem, and it is nothing more than that of including 
additional species in any monotypic genus with a very specific, 
highly descriptive name, of including the two new species in 
Schismatorhynchos 1s that both lack a cleft in the snout. However, 
the problem is not so much that the two new species lack a cleft snout 
but that the highly descriptive generic name Schismatorhynchos is 
apt for only one species of the genus. Generic names serve two 
functions in modern classification: 1) the first element of a unique 
binomen; and 2) the name of a group of species that are close 
phylogenetic relatives of each other. The first function is a matter of 
nomenclature. The second function lies within the realm of the 
science of Systematics and we believe it to be of greater importance. 
Since there is good evidence (the oro-labial features) that the two 
new species are close relatives of S. heterorhynchos we include them 
in Schismatorhynchos even though they lack a cleft snout. This 
leaves the name Schismatorhynchos apt for only one of the three 
species in the genus but we do not see this as reason enough to 
propose a new generic name for the other two, especially since S. 
holorhynchos 1s probably more closely related to S$. heterorhynchos 
than it is to §. endecarhapis. 
Lobocheilos is herein recognised as that group of Southeast Asian 
cyprinids possessing a very wide median lobe of the lower lip and 
with the lower and upper lips continuous around the corner of the 
mouth (Fig. 1D). This definition conforms to that of Smith (1945), 
who followed de Beaufort’s (1927) comment on an Indo-Australian 
subgroup of Tylognathus Heckel. The two new species of 
Schismatorhynchos could have been assigned to Lobocheilos, as lip 
structure (generally) and scale and vertebral counts of the new 
species of Schismatorhynchos do conform to those of species of 
Lobocheilos. Some may prefer such an assignment, especially since 
the new species lack a rostral cleft, but to do so on the basis of the 
absence of a rostral cleft ignores the two derived oro-labial charac- 
ters which all species of Schismatorhynchos share. As we pointed 
out above, we choose to focus on the evidence that the two new 
species are closely related to S$. heterorhynchos rather than their lack 
of a cleft in the snout. 
A more practical problem is that Schismatorhynchos 
endecarhapis will not key to genus using any regional key in 
general use of which we are aware (Weber and de Beaufort, 1916; 
Smith, 1945; Inger and Chin, 1962; Kottelat et al., 1993). The 
initial problem encountered in these keys is the count of branched 
rays in the dorsal fin. Schismatorhynchos heterorhynchos Bleeker, 
S. holorhynchos, and members of the closely related genus 
Lobocheilos possess fewer than 10, usually only eight, branched 
D.J. SIEBERT AND A.H. TJAKRAWIDJAJA 
rays in the dorsal fin. Schismatorhynchos endecarhapis, with 11 
branched rays in the dorsal fin, fails this distinction, instead fall- 
ing into Tylognathus, Labeo, or Cirrhinus (depending on which 
key is used). 
The second problem is that a deep rostral cleft is used to separate 
Schismatorhynchos andLobocheilos. Both new species of Schismato- 
rhynchos fail this distinction. However, to our. knowledge, the 
characters of upper and lower lips not continuous around the corner 
of the mouth and presence of a frenulum between the lower lip and 
the isthmus always separates Lobocheilos and Schismatorhynchos 
correctly. 
Annotations to keys to cyprinid genera of the 
region. 
We suggest the following annotation to the Cyprininae key of Weber 
& de Beaufort (1916; p. 94): 
1. Suborbital bone covering greatest part of cheek; lower jaw with sym- 
physial tubercle; the broadly reflected lower lip not separated from jaw 
Hose Soon sty az vntis sus ose REE ataa taeda? au Coa aoe o oO cae Barbichthys 
2. Ring of suborbital bones not enlarged, lower jaw without symphysial 
tubercle; lower lip distinct from lower jaw. 
a. lower and upper lips not continuous around the corner of the jaw 
wei aries Sie once cPuswenaazen tent tadsancenes omen aad Schismatorhynchos 
b. lower and upper lips continuous around corner of lower jaw. 
aa. Dorsal with 10-18 branched ray .............--.2sccesccereeeeeeeeees Labeo 
bb. Dorsal with 8—9 branched rayS .............:ceceeeeereees Lobocheilos 
The key to genera of Cyprinidae of Kottelat, et al (1993;p. 29) can 
accommodate an expanded Schismatorhynchos with the following 
modifications (which make couplet 30 unnecessary). 
27a. Suborbital bones enlarged and covering most of cheek (Fig. 109); lower 
jaw with a symphysal knob; lower lip reflected backwards,but not 
Separated MOMa AW: ccs: c.ccssece eset sanewarsm sens coon voese eee Barbichthys 
27b. Suborbital bones not enlarged; no symphysial knob on lower jaw; lower 
lip distinctly separated from loWer Jaw ............-csscecesceereeeeeseees go to * 
*a. lower and upper lips not continuous around corner of lower jaw 
sbaie ad dates dbeasv tee tec degen eit Re Schismatorhynchos 
adele sade Salea Peat ds oate deeb awa aysoee eaten aaiaees saxtcrepeee tN eats sare go to 28 
28a. 10-18 % branched dorsal rays ................::c+0s00+ go to 29 
28b. 8-9 ¥2 branched dorsal rays .........-..::eseeeeee Lobocheilos 
ACKNOWLEDGEMENTS. Many institutions and individuals contributed to 
make our survey efforts in the Barito River possible. The Indonesian Insti- 
tute of Sciences (LIPI) granted permission to conduct research in 
Kalimantan; the Natural History Museum and the Research and Develop- 
ment Centre for Biology (PPPB), Bogor allowed the authors to make this 
effort The Worshipful Fishmongers Co., London provided a generous 
grant to fund the second expedition; the Royal Society, London, the 
Godman Fund for Exploration, London, the Natural History Museum, 
London, and the National Museum of Natural History, Washington, D.C. 
all contributed toward the first expedition. Project Barito Ulu provided 
invaluable logistic and other support for the first expedition. The Sumanti 
family of Desa Maruwei, Kalimantan Tengah provided gracious hospital- 
ity, without which the holotype would never have been obtained. Rony 
Huys is thanked for translation of old Dutch. 
