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Inhabits large
rivers and lowland floodplains. Occurs in riffle and deep
slow reaches. Moves out into the flooded forest where it
feeds on leafy plant matter, phytoplankton and insects.
Migration pattern is markedly different above and below the
Khone Falls in the Mekong basin. Below the falls, it makes
an upstream migration from Phnom Penh to the Khone Falls
between November and February. From April to July, it
migrates in the opposite direction, from Khone Falls and
downstream, constituting mainly of sub-adults up to about 50
cm. Above the Khone Falls, from Klong Kaem District,
Ubolratchatani in Thailand, fish migrates upstream in
February; at Khemmaratch further upstream in Ubolratchatani,
it moves upstream in March-April; and at Mukdahan, it goes
upstream in May. However, it migrates downstream at Klong
Kaem in June-July. Only downstream migrations are reported
in the Mekong Delta in Viet Nam, constituting mainly of
juveniles (2-20 cm), with the smallest fish mainly in
June-July and fish between 10 and 20 mainly from September
to November. From Xayabouri in Laos to Chiang Saen in
Thailand, upstream migrations take place from March to
August. This appears to be two distinct migrations: one of
sub-adults measuring 15-50 cm during March-April and another
one of larger fishes of sizes 40 to 90 cm during June-July.
Not known to persist in impoundments. Individuals caught
with dais or traps are often immediately kept alive in fish
cages for future sale. Marketed fresh and sometimes dried
and salted. Known to reach up to 15 kg in Thailand. |
