Description:
Dorsal spines (total): 1; Dorsal soft rays (total):
7; Anal soft rays: 12 - 14; Vertebrae: 44 - 46. Can
be differentiated from its congeners by a unique combination
of the following characters: head length 31.0-34.3%
SL; dorsal to adipose distance 7.3-10.9% SL; length
of dorsal-fin 27.3-30.8% SL; post-adipose distance
14.7-16.2% SL; interorbital distance 28.1-31.1% HL;
presence of filamentous extensions on the first three
dorsal-fin rays in adults. Depressed dorsal fin reaching
adipose fin; adipose fin same color as body; body
and fins a uniform dark brown; crenulate ridge along
anterior edge of pectoral spine; 8 branched anal-fin
rays. Elongated upper caudal lobe ending in a filament.
Habitat: The species is found in
a wide variety of lentic and lotic habitats, although
it is more frequently encountered in larger rivers
with a substrate of sand or mud. Reproduction:
It migrates into smaller tributaries and out into
flooded areas occurs with the rising water level,
with spawning taking place during the months of June-July.
When water levels start to recede at the end of the
flood season the fish return to the main river channel
where they remain in deep pools during the dry season.
At several places throughout the basin, migrations
are guided by the lunar phase: in the Mekong in Cambodia,
the early dry-season upstream migrations occur just
before, and during, the full moon. Diet:
This species feeds mainly on fishes, crustaceans,
aquatic insect larvae and plant fragments. Etymology:
The genus name Hemibagrus:
Hemi- half; bagrus- from 'bagre',
a South American name for a catfish, but is only used
for African and Asian species. The
specific name filamentus: referring
to filamentous extensions of first 3-4 branched rays
of dorsal fin, their total height equal to length
of head.
Common
Name:
None
Synonyms:
Macrones
(Hemibagrus) filamentus
Family:
Bagridae
Distribution:
Asia:
Middle
and lower Mekong River basin of Laos, Thailand, and
Cambodia. Type locality: Cambodge.
Hemibagrus
filamentus Line drawing. From Cambodia, Mekong River
Hemibagrus
filamentus In Siam Aquarium, Thailand 2006
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