Synonyms:

Homaloptera tetraloba Mai, 1978

original description

Homalosoma tetraloba (Mai, 1978)

obsolete combination

Vanmanenia striata Chen, 1980

misidentification

Vernacular names:

Ca way bang

Vietnamese

Pa khi, pa pan ca

Thai

Etymology:

Generic name ‘Vanmanenia’ is a dedication name to Mr. Johan Van Manen, former General Secretary of the Asiatic Society to Bengal. Gender: feminine (Hora, 1932).

Specific epithet ‘tetraloba’ is an allusion to the structure of the lower lip, which is divided into four lobes; a noun.

Size / Weight:

SL 43-92 mm; TL 54-113 mm, original description (Mai, 1978, translated in Kottelat, 2001a)

80.2 mm SL, 95.3 mm TL, EPC 0563, largest specimen of collection, Mengyejiang River, Puer County, Yunnan Province, China (ME, 2010-03-07).

Diagnosis:

D 2,8; A 1,5; V 1,9; P 1,16; lateral line scales 105-115; body depth/SL 17.5 %; HL/SL 20.9 %; eye diameter/body depth 18.6 %; interorbital distance/body depth 40.4 %.

Body compressed, flattened in head area and slender on caudal peduncle. Eye moderately small, dorsally placed on head side. Interorbital distance large. Small nostril near eye and far from snout. Small mouth, circular. Four maxillary barbels arranged in a row and one pair of small barbels at rictus. Body covered by tiny cycloid scales. Pectoral and pelvic areas not scaled. Lateral line complete. Lower lip divided into 4 lobes. Dorsal fin rays not spinous. Dorsal origin in front of pelvic insertion and in middle of distance from snout to caudal-fin base. Pectoral fm widely expanded. Anus near pelvic fin. Caudal deeply forked. Upper lobe smaller than lower one.

Coloration: Grey, body vertically barred. A black stripe along lateral line. Dorsal and caudal fins barred (Mai, 1978, translated in Kottelat, 2001a).

Sex differentiation:

No sexual dichromatism and dimorphism.

Distribution:

The terra typica is not noted in the original description but can be referenced as Tay Bac, NW Vietnam, Red River basin (Mai, 1978, translated in Kottelat, 2001a).

Lixianjiang River subbasin of Red River basin; syntop with nemacheilid loaches such as Schistura callichromus and S. laterivittata in the riffle section of EW-CN 66-09 (Mengyejiang River 勐野江, tributary to Lixianjiang River李仙江, Red River 红河 basin, Yunnan Province, China). For biotope details see S. callichromus (ME, 2009-12-30, 2010-01-06). Frequent; with S. callichromus predominating species in the riffle section. 

Ecology:

Benthic, patrolling in squads of 3-5 individuals, permanently foraging for food, grazing on biofilm on the smooth surfaces of rocks and boulders; average individual distance is 15 cm within the group.

No data on reproduction but fry (10 mm TL) appear along the banks in areas with almost no current; entirely black with hyaline larval adiposal crest; feeding upon detritus; no grouping tendancy, but living singly (ME, 2009-12-30, 2010-01-06). 

Conservation status:

IUCN Red List not evaluated.

Aquarium maintenance:

Highly aerated water; moderate to high current; rocks and boulders with smooth surfaces; tablets with high Spirulina content are an appropriate diet; freshly wild caught individuals are demanding feeders.

Not to be companied with extremely agile feeders.

Remarks:

Vanmanenia striata Chen, 1980 is considered a junior synonym of V. tetraloba by some authors. In fact, it shows a different phenotype and is a valid species. V. striata populates the Yuanjiang River, which is the upper Red River, while V. tetraloba occurs in the Lixianjiang River sub-basin of the Red River basin.

See related online article.