The author's friend John, collecting fish in a blackwater stream.
The Batang Rajang (or Rajang River) is the longest river in Malaysia. The aquatic flora and fauna in this mighty
river are among the most diverse in my
country—every time I come to visit this
river basin, I find a lot of beautiful fishes
and aquatic plants in different places that I
had not explored before.
At the end of the rainy season, my
friend John and I decided to drive to the
town of Sibu, from Kuching, to collect
Cryptocoryne for our aquariums. The drive
lasted six hours before we reached the first
collecting spot, a blackwater river mixed
with brackish water near Sibu. We walked
past the muddy trail to a shaded area near
the river, where a clump of Cryptocoryne
lingua was growing lavishly. This species
prefers to grow in either a freshwater or
brackish area with tidal influence, where
the main substrate consists of silt.
After collecting C. lingua, we drove to a
nearby peat swamp for another species of
Cryptocoryne. In this location, an acidic
blackwater stream flows past an old
rubber plantation. C. pallidinervia grows
abundantly in this stream in either open
or shady areas. When I stood closely to the
Cryptocoryne in the stream, I saw a school
Cryptocoryne pallidinervia growing in the blackwater stream.
of tiny fish swim past my legs—they
happened to be one of the smallest fishes
in the world, Paedocypris micromegethes.
This tiny little fish is always overlooked by
people; the length of its body is typically
less than 1. 2 cm (less than ½ inch). The
species is also very fragile—I learned that
if it is exposed to the air for even a few
seconds, it won’t survive for long.
Besides Paedocypris micromegethes, we
also caught Parosphromenus allani, Betta
akarensis, Rasbora kottelati, and some other
blackwater fishes common to the Sibu area.
After packing the fish and plants into
our car, we headed north to Sibu. Before
crossing over the Rajang River on the
Lanang Bridge, we turned to a small
country road to explore the area. When
we reached a canal, we were stunned by a
view that neither of us had seen before in
our lifetime! It was here that we witnessed
thousands of Cryptocoryne lingua growing
along the canal and the nearby rivers out
in the open, covered by a layer of mud.
Unfortunately, all of them disappeared into
the water when the tide came in a few
The next day, we drove west along the
Rajang River to collect Cryptocoryne yujii
from another blackwater river. Before
reaching our destination, we spotted a
beautiful swamp orchid Papilionanthe
hookeriana, which grows abundantly in the
At the next location, we saw three species
of aquatic plants growing in this acidic river.
There were dark-reddish colored Barclaya
mottleyi, light-green colored Cryptocoryne
yujii, and the hair grass Eleocharis sp.
The substrate is very soft and acidic peat
soil. We could not walk into the middle
of the river, as the soil was too soft, so we
One of the smallest fishes in the world,
Tropical Fish Hobbyist www.tfhmagazine.com