186 
Lateral line complete, with 76—90 pores, incomplete in specimens 
less than about 30 mm SL. 
In alcohol body pale yellowish with 10-15 irregular dorsal sad- 
dles, saddles wider than saddle interspaces. There are 8—13 blotches 
along the lateral line, blotches progressively larger posteriorly (Fig. 
|b). In larger specimens blotches may be fused to form longitudinal 
stripe, especially in posterior half of body (9 of 29 specimens with 
such a longitudinal stripe). No spot present at anterior base of dorsal 
fin. Two dark marks at base of caudal-fin rays: the larger, more 
intense mark a vertically elongate dark mark in series with lateral 
blotches; the smaller, a dorsally situated, oval, dark spot, perhaps in 
series with dorsal saddles. 
SEXUAL DIMORPHISM. In our material, the largest individuals are 
female; no male exceeded 48.5 mm SL while several females 
exceeded this length, the longest of which is 53.4 mm SL. Males 
(39.8mm SL and over) possess a large subocular flaplet (Fig. 2) 
below the anteroventral margin of eye and have a greater number of 
tubercles in the mid-body region than females. In males retrorse 
tubercles are present on each scale in the region between the pelvic 
fin and the lateral line, in well-defined rows. Tubercles are also 
present in females in this region, but they are scattered rather than 
present in rows on every scale; tubercles of females are also smaller 
than those of males. Above the lateral line in the mid-body region 
both sexes have tubercles variously scattered. 


INDIAN 
OCEAN 

q 
S 
oS e B 
98° 



Fig.6 Drainage map of Gunung Leuser National Park area from which 
N. tuberigum materials have been captured; the shaded area of the inset 
is the area covered by the drainage map. & = S. Lembang localities near 
Suag Balimbing Research Station; target symbol = type locality. W = S. 
Alas drainage localities near Ketambe Research Station. 
R.K. HADIATY AND D.J. SIEBERT 
REPRODUCTION. Yellow to orange mature eggs were visible though 
the thin abdominal skin of female with a distended belly. Another 
female, 48.5 mm TL, contained 4192 eggs of uniform size (0.61 mm 
mean diameter). Fishes that spawn all eggs in a single event are 
known as total spawners (Welcomme, 1979). One of the character- 
istics associated with total spawning is uniform egg size. Since eggs 
of N. tuberigum were observed to be of uniform size we interpret the 
species as most likely being a total spawner. 
DISTRIBUTION AND HABITAT. Nemacheilus tuberigum is known 
only from Sungai Lembang, Suag Balimbing Research Station and 
Sungai Alas, Ketambe Research Station in the region of Gunung 
Leuser National Park, Aceh, Sumatra (Fig. 6). It was taken from 
streams of small to moderate size, mostly in shallow, clear water, but 
a few juveniles were taken from murky water. The substrate over 
which it was found varied from gravely to sandy. Species co- 
occurring with N. tuberigum were: Homaloptera ripleyi, H. 
gymnogaster, Tor tambra, Rasbora lateristriata, R. sumatrana, R. 
meinkenii, Glyptothorax cf. major and G. cf. platypogonoides. 
Given the lack of general information on fish distributions in 
Sumatra it would not be surprising to find the species elsewhere. 
ETYMOLOGY. The epithet tuberigum, a noun, is derived as sug- 
gested in Brown (1956: p. 44). It is constructed in reference to the 
comparatively large tubercles on either side of the lateral line on the 
anterior part of the caudal peduncle; it is from the latin words tuber, 
a neuter noun meaning swelling, and mangus, meaning large, the 
later dismembered to —gus, but modified appropriately to the gender 
of tuber. 
COMPARISONS WITH OTHER SPECIES 
EXTERNAL CHARACTERS. The presence of a row of enlarged 
tubercles on the caudal peduncle on the apex of elongated scales of 
the scale rows immediately above and below the lateral line scale 
row immediately separates N. tuberigum from all other known 
Nemacheilus except N. selangoricus and N. spiniferus. The lack of 
a dark spot at the anterior base of the dorsal fin immediately 
distinguishes N. tuberigum from these later two taxa; additional 
differences from these two species are recorded in Table 2. Never- 
theless it is worthwhile to consider some general comparisons with 
other Nemacheilus from Sumatra, which include (Kottelat et al., 
1993; Kottelat & Whitten, 1996) N. fasciatus, N. kapuasensis, N. 
lactogeneus, N. longipinnis, and N. pfeiferae and the possibly valid 
nominal taxa N. dunckeri, N. papillosa and N. jaklesii. A third party 
reviewer also requested a comparison to N. masyae, a species 
present in peninsular Thailand and Malaysia at about the same 
latitude as N. tuberigum. 
COLOUR PATTERN. The colour pattern of N. tuberigumis a series of 
dorsal saddles and midlateral blotches, a colour pattern general for 
all Sumatra Nemacheilus of which we are aware except N. 
lactogeneus. Nevertheless, N. tuberigum is distinguishable from 
some of the other species of Nemacheilus from Sumatra in matters of 
colour pattern details. 
Nemacheilus fasciatus, N. jaklesii and N. longipinnis each pos- 
sess a dark spot at the anterior base of the dorsal fin, which N. 
tuberigum lacks. In addition, N. jaklesii appears to have a colour 
pattern of dorsal saddles nearly confluent with relatively deep 
vertical, lateral bands rather than blotches along the lateral line. The 
photograph of the type of N. longipinnis reproduced in Kottelat et al. 
(1993; Fig. 139) indicates a dark spot at the base of the anterior part 
