Rasbora pauciperforata

Rasbora pauciperforata, (Weber & De Beaufort, 1916) from the Family Cyprinidae, (The Red Line Rasbora)

A small freshwater fish with a streamlined, compressed body, the Red Line Rasbora has a wide habitat range from West Malaysia, Indonesia (Sumatra) and Borneo. It is an inhabitant of peat swamp basins, pools and natural ditches. It is usually found in clean, tannic, soft waters (2-4˚H) with a pH ranging from 3.5 to 6.50. Water temperatures in their natural elements are typically 25˚-28˚C. It favors indirect sunlight and quiet, deep-shaded waters with very gentle currents.

Although the body is well developed, it struggles in fast flowing currents and will usually seek refuge in crevices or less turbulent waters. It can be found in depths ranging from shallow up to a meter deep. Banks with well-developed vegetation such as weeds, over-grown grass and floating plants are their favorite haunts where they typically swim within mid-water levels. When they encounter danger, they usually attempt to escape by diving to the floor bed or seeking refuge in thick vegetation where they will remain until the danger passes over.

A single red band runs from the tip of the mouth to the base of the tail. The scales above the line have a peppery dust pattern on the edges while the scales on the belly have a wedge-shape pattern comprising of small dark pigmentation cells. Fins do not have any markings. Overall, captive fishes kept in acidic, tannic waters will bring out true colors.

Sensitive to heat, light and vibrations, the Red Line Rasbora is quite shy and generally avoids open spaces devoid of plants and bright spaces. In a bare tank, specimens usually sulk at the bottom of the darkest corner. A school of at least five fishes is recommended. Singular fishes are timid but gain confidence in the company of fish schools, even if it is of different species.

Wild caught specimens acclimatized fairly fast in captivity, accepting frozen and dry foods readily. Bright lights should be avoided. A typical tank set-up should comprise of a heavily planted tank with indirect light. Frequent water changes with the replacement water filtered over peat moss is highly recommended to encourage the fishes to show their prominent red line. Once properly acclimatized, the Red Line Rasbora will be emboldened to show itself in open spaces but they will usually not stray away from nearby plants or cover. They typically swim in short distances, hover momentary by twitching their fins to stay suspended and dart around in bursts of speed. The fish is a fairly good jumper so a tank cover is recommended.

This fish’s diet in the wild is not really known but their habitat usually supports a wide range of plankton matter such as aquatic larvae, insects, tubificid worms and small crustaceans such as Daphnia. The Red Line Rasbora will adapt to frozen and dried foods readily.

The Red Line Rasbora can reach a length of 6 cm. In the wild, they typically form small to medium sized loosely-formed schools. Females are larger than the males. A very peaceful fish, this is an excellent species for a community bio-type tank.

 

Rasbora kolachlorma

 Rasbora kolachlorma (Bleeker, 1851) from the Family Cyprinidae (The Clown Rasbora)


The Rasbora kolachlorma’s any closest resemblance to a clown are the two or three big dark green spots that flank both sides of the fish. It is also known as the Iridescent Rasbora. It has a rich, brown color that is overlaid with scales that have beautiful iridescent colors which is very evident when taken out from the water. A greenish fairy-dust pattern can be seen decorating the top of the fish from head to base of the tail. Fins are maroon-ish brown and do not have any markings. Found in peat swamp basins, it has a wide range in Borneo and Indonesia (Sumatra) and inhabits a wide range of habitats which includes shallow streams and peat swamp forests.

Their favorite habitats are submerged areas with thick vegetation, tree-roots, overgrown grasses and knee-deep waters under shade. They have a stream-lined body which enables them to traverse in fast currents especially during heavy rains but they prefer quieter bodies of water. This is a relative large, elegant Rasbora attaining a length of 11cm, as observed in the author’s specimens.

This fresh water fish’s habit parameters are usually clean, tannic, soft (2-5˚H) waters with a pH of 4.0-6.8 with a gentle water current. Water temperatures can vary from area to area but generally in the jungle and peat swamp fed streams, temperatures range from 25˚ -28˚C. Occasionally, they can also be found in stagnant bodies of waters, which usually is the result of a heavy rain overflow which traps them temporary. When the water levels rise with the next rains, they usually slip out of the stagnant pool to new hunting grounds. In the wild, they form small, loose schools with an average of three to five fishes.

Breeding is observed during the rainy season when the water levels rises and floods the jungle floors, sometimes for several days. Mature fishes gather in larger schools sometimes as many as thirty fishes and make migratory trips into the flooded jungle to breed. Favorite breeding platforms are peaty, grass over-grown areas with thick jungle canopies. Low light levels due to the jungle’s thick canopies are commonly observed.

Hatched fries are usually found in these flooded jungle floors in very gentle currents but fish count is usually about two to three fishes per square meter. As the waters slow ebb, some fries will follow the currents out and a few will be trapped in pools until the next rains come. The flooded jungle floor is rich in suspended microscopic food such as daphnia and aquatic larvae, and these form part of the foods for the fish and fries.

Juvenile fishes are observed to be competitive as they frequently chased and push weaker siblings away to dominate food resources and territories. This behavior is also observed in wild-caught adult specimens.

Scraping behavior is usually limited to their own specie. Otherwise, this is a very peaceful, benthopelagic fish that will fit a large community tank.

Wild adult fishes are observed to be surface feeders, preying on insects on the water such as water skaters and floating foods. However, domesticated specimens will readily adapt to frozen, dry foods with a high protein matter and low carbohydrate content. Wingless fruit flies are an excellent source of protein for them. Dry foods should be of the floating type. Rasbora kalochlorma often exhibit the ‘Squirrel Syndrome” as I called it. They will aggressively collect as much food as they can in their mouth or cheeks while consuming it. Hence in a community tank, it is necessary to closely observe that the rest of the occupants will have sufficient food to eat.

Properly cared for specimens are generally long-lived with an average life-span of three years. Rasbora kaloclorma is an excellent jumper with the ability to even jump out when they are netted so a tightly covered tank is recommended. Adult specimens are often observed as solitary fishes in the aquarium but will readily regroup as a school of fishes during feeding or mating times.

This is an excellent fish for the community bio-type tank. No commercial breeding has been observed for this fish and most of the Rasbora kalochlroma for the aquarium trade are wild-caught. Again with encroaching development into their habitats, this would be a good fish for breeders to include in their list.

Field Trip to the Kayan River Basin (Revised)

21st October, Wednesday started out as a fine warm day with an ambient temperature of 31'C. A field trip to the Kayan River Basin was the order of the day. We headed up East first as my partner-in-crime (P.I.C.) wanted to visit his parents first. Upon arriving, they were out tending to their rice fields. Rice harvesting has started several days ago. 

Lunch was the next order of the day as we drove into town in search for grub. We headed towards the shops to grab some food to tank up. I, particularly warmed up to the Mee Mamak the first time, cooked by one of the stall operators. 

Unfortunately, the dish tasted different every other next visit. The last meal was quite a disaster as the dish did not resemble Mee Mamak at all, so I’ll be looking for new grub on my next visit.

After lunch, we started heading back towards Kuching and turn into a kampong (village) on the right side, we decided to look around in that area. Pushing our way into the thick undergrowth, we trekked towards the interior until we came across a shallow, clear stream. The temperature difference was immediately noticeable as we entered the jungle canopy as it was cool and comfortable. There were a few persistent mosquitoes determined to make a meal of us. My eyes are now on the lookout for leeches and Assassin bugs, the latter which can cause a really painful bite that last for days.

P.I.C. started sampling and immediately netted a few wild adult Betta ibanorum. This is a common fighting fish in this area. Meanwhile, I had started sampling further upstream. Dipping my net in yielded a few Rasbora caulimaculata, Rasbora einthovenii and Rasbora pauciperforata. Sweeping under the leaves on the sand-bed, there was a small maroon colored fighting fish caught in the net. Betta brownorum but without the greenish-blue spot. I thought unusual to have found this fish in this type of topography. 

Several specimens were caught later, and all fishes lacked spots, which led me to conclude that these could be Betta rutilan. Collecting this fish was time-consuming as they could only be found scattered, almost always singularly. As seen in these photographs, the paler fish is the female as the other fish is the male.

This was a surprising find as I had thought that this specie can only be found in Indonesia. The day was already late so it's time to pack up. There will always be another day. Who knows what one may find next.