Conspectus cobitidum - Raffles Museum of Biodiversity Research

Material. — Theriodes sandakanensis: ZRC 37645, 16 (of
17); CMK 11557, 2; 10.5–35.0 mm SL; Borneo: Sabah:
Kinabatangan drainage at SAFODA, near Batu Puteh, K. K.
P. Lim et al., 7–13 Apr. 1994. - ZRC 45473, 2 (of 3), 21.8–
22.1 mm SL; Borneo: Sabah: Lungmanis, Goh Y.-Y., 27 Sep.
1998.
Speonectes, new genus
Type species. — Sundoreonectes tiomanensis Kottelat, 1990.
Diagnosis. — Speonectes is distinguished from the other
genera of Nemacheilidae by the following combination of
characters (but none unique to it): anterior and posterior
nostrils adjacent; rim of anterior nostril as a short tube with
posterior edge produced in a long filament (‘nasal barbel’);
processus dentiformis present; lower lip with a median notch;
lateral line present, incomplete, reaching vertical through end
of anal-fin base; axillary pelvic lobe present, rudimentary;
pelvic-fin origin about at vertical through dorsal-fin origin;
anus closer to base of pelvic fin than to anal-fin origin; dorsal
and ventral crests on caudal peduncle, supported by
procurrent rays; posterior chamber of gas bladder large and
somewhat globulous, located dorso-posterior to stomach and
connected to encapsulated anterior part by a long slender
duct.
The ‘nasal barbel’ is also known in other nemacheilid species
that had earlier been placed in Oreonectes (e.g. Bănărescu
& Nalbant, 1995: 455) but are now placed in Oreonectes,
Lefua, Indoreonectes and Sundoreonectes (Kottelat,
1990b; Prokofiev, 2005). A few species of Schistura also
have a ‘nasal barbel’, although less developed; they are immediately
distinguished from Speonectes by their barred
colour pattern, anus closer to base of anal-fin origin than to
pelvic fin; caudal fin emarginated or forked; and (for those
species in which this character has been examined) posterior
chamber of gas bladder absent or immediately adjacent
to encapsulated anterior part.
Speonectes is distinguished from Oreonectes in having: an
almost complete lateral line, which reaches to a vertical
through the end of the base of the anal fin (vs. absent or up
to 18 pores, not reaching pelvic fin; Du et al., 2008); a large
posterior chamber of the air bladder, located dorso-posterior
to the stomach and connected to the encapsulated anterior
part by a long slender duct (vs. in direct contact with the
bony capsule); the dorsal-fin origin about on a vertical
through pelvic-fin origin (vs. conspicuously behind the base
of the pelvic fin); adjacent nostrils (vs. widely separated,
posterior one at short distance of anterior margin of orbit);
and the anus closer to the base of the pelvic fins than to the
anal-fin origin (vs. immediately in front of anal-fin origin).
Oreonectes occurs in southeastern China and northern Vietnam.
Speonectes is distinguished from Lefua in having: an almost
complete lateral line, which reaches to a vertical through the
end of the base of the anal fin (vs. no lateral line); the dorsal-
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fin origin about on a vertical through pelvic-fin origin (vs.
above posterior extremity of pelvic-fin base); adjacent nostrils
(vs. widely separated, posterior one at short distance of
anterior margin of orbit); and the anus closer to the base of
the pelvic fins than to the origin of the anal fin (vs. immediately
in front of anal-fin origin). Lefua occurs in the Amur
drainage, Korea, northeastern China and Japan.
Speonectes is distinguished from Indoreonectes in having:
an almost complete lateral line, which reaches a vertical
through the end of the base of the anal fin (vs. reaching at
most to a vertical through middle of pectoral fin); a large
posterior chamber of the air bladder, located dorso-posterior
to the stomach and connected to the anterior encapsulated
part by a long slender duct (vs. rudimentary and adjacent
to the bony capsule); the dorsal-fin origin about at a vertical
through the pelvic-fin origin (vs. above the posterior extremity
of the pelvic-fin base or behind); and the anus closer to
the base of the pelvic fin than to the anal-fin origin (vs. immediately
in front of anal-fin origin). Indoreonectes is known
only from Peninsular India.
The only known species of Speonectes (S. tiomanensis) inhabits
a cave on Tioman Island (off Malay Peninsula) and
was earlier placed in the genus Sundoreonectes, which includes
at least two species from the highlands of Borneo.
Besides the features commonly observed in cavefishes (reduced
eyes, white body, etc.), Speonectes is distinguished
from Sundoreonectes in having: a median notch in the lower
lip (vs. no notch, lip continuous along the anterior edge, but
with numerous narrow furrows; postlabial groove almost
continuous, interrupted medially only by two very narrow
frena); an almost complete lateral line, which reaches to a
vertical through the posterior extremity of the base of the
anal fin (vs. reaching to above pelvic fin); the anus closer to
the base of the pelvic fin than to the anal-fin origin (vs. immediately
in front of at anal-fin origin); and the caudal fin
slightly emarginate (vs. truncate or slightly rounded). Sundoreonectes
was distinguished from Oreonectes, Lefua and
Indoreonectes by the absence of a frontal fontanelle; it is
not possible to dissect the single specimen of S. tiomanensis
available to me to check this character, but no fontanelle
could be felt through the skin with a needle.
Etymology. — From the Greek σποζ (speos: a cave, cavern,
grot) and νκτηζ (nectes: a swimmer); a reference to the cave
habitat of the only known species of the genus. Gender masculine.
Remarks. — Unpublished molecular data (V. Šlechtová and
J. Bohlen, pers. comm.) shows that Speonectes tiomanensis
belongs to a lineage very distinct from Oreonectes, Lefua
and Sundoreonectes.
Material. — Speonectes tiomanensis: CMK 15963, 1; Malaysia:
Tioman Island. Indoreonectes evezardi: CMK 6439,
2; India: Madhya Pradesh. Oreonectes platycephalus: CMK
7207, 3; Hong Kong. - CMK 14892, 5; Vietnam: Quang Ninh.
Sundorectes sabahensis: CMK 6435, 2; 17455, 10; Malaysia:
Sarawak. Lefua costata: CMK 21951, 9; South Korea.