A review of the Nemacheilinae genus Oreonectes Günther with descriptions of two new species (Teleostei: Balitoridae)
Author
Du, Li-Na
Author
Chen, Xiao-Yong
Author
Yang, Jun-Xing
text
Zootaxa
2008
1729
23
36
journal article
10.5281/zenodo.181269
c43ca315-e20f-4b12-aa9d-88e653e05d71
1175-5326
181269
Oreonectes polystigmus
sp. nov.
Fig. 7
Holotype
:
KIZ
2001060507,
57.7 mm
SL,
68.6 mm
TL
, from Dabu Village, Guilin City, Guangxi Zhuang Autonomous Region,
China
,
June 2001
, donated by Mr. Lan Jiahu, Guangxi Du’an County Animal Husbandry and Aquaculture Bureau,
April 2003
.
Paratypes
:
9 ex.
KIZ
2001060502–06,
35.1–53.6 mm
SL,
42.2–64.5 mm
TL
;
KIZ
2001060508–10, 42.0–
46.4 mm
SL,
50.2–55.9 mm
TL
. Location and date are the same as for the
holotype
.
Diagnosis:
Anterior and posterior nostrils separated by short distance; anterior nostril elongated into barbel-like structure; tip of anterior nostril reaching middle of posterior nostril; caudal fin rounded; body and belly completely covered by scales; lateral line incomplete, with 6–8 pores; cephalic lateral-line system with 7 supraorbital, 4+7 infraorbital pores; sexual dimorphism observed: males have genital papilla located immediately posterior to anus; gonad opens at end of fleshy prominence.
Description:
Body elongate and compressed; head compressed; snout pointed; snout shorter than postorbital portion of head; mouth inferior; lip surface smooth; lower lip with notch, completely interrupted by longitudinal groove; jaws completely covered by lips; formalin-preserved specimen has dark brown spots on upper lip; three pairs of barbels, inner rostral barbel reaching vertical of posterior margin of eye, outer barbel reaching almost vertically of branchiostegal rays, maxillary barbel reaching vertical of pectoral-fin origin, barbels with brown spots; anterior and posterior nostrils separated by short distance, anterior nostril tube-like; distal margin of nostril tube truncate, reaching middle of posterior nostril; eyes normal.
Distal margin of dorsal fin rounded; dorsal-fin origin posterior to pelvic-fin origin; predorsal length 57.0– 64.1% (59.5) SL; pectoral fin reaches about 1/2 distance to pelvic fin; distal margin of pelvic fin reaches anus; distance from anus to anal-fin origin is 1.5 times longer than eye diameter; less developed caudal-adipose keel on caudal-peduncle; caudal-peduncle length 1.1–1.5 (1.3) times longer than depth; caudal fin rounded; whole body covered by tiny scales, excluding head; lateral line incomplete, with 6–8 pores; cephalic lateral-line system with 7 supraorbital, 4+7 infraorbital pores; vertebra 4+30~33 (3). Air-bladder has two chambers, posterior chamber developed, filling body cavity, connected with anterior chamber by long, slender tube; intestine straight. Fin ray counts: P, 10; D, 6–7; V, 6; A, 5; C 14–15.
FIGURE 6.
Distribution of
O. platycephalus
in Jinxiu County, Guangxi.
Color pattern (preserved in formalin):
Body yellowish brown with many irregularly shaped spots, dorsal fin and caudal fin with irregular spots on rays, other fins hyaline or rays with black.
Sexual dimorphism:
Males have genital papilla located immediately posterior to anus; gonad opens at end of fleshy prominence.
Distribution:
Known from the Dabu Village, Guilin City, Guangxi Zhuang Autonomous Region,
China
.
Etymology:
From Greek
poly
and
stigma
, meaning numerous marks, in reference to the presence of numerous dark brown spots on the body of this species. Gender masculine.
Remark:
From the body shape, this species appears to be most closely related to
O. platycephalus
and shares the following characteristics: dorsal-fin origin posterior to pelvic-fin origin; body and belly completely covered by scales; cephalic lateral-line system with 2+2 supratemporal and 7 preoperculomandibular pores; caudal fin rounded.
However, it can be distinguished from
O. platycephalus
by the following characteristics: cephalic lateralline system with 7 supraorbital versus 8; 4+7 infraorbital versus 3+10; lateral line incomplete, with 6–8 pores versus 16–18; body with many different spots versus body plain; posterior portion of air-bladder developed, filling the body cavity versus reduced, reaching the vertical of pectoral-fin base.