Borneo sucker is a small fascinating freshwater fish that has become quite popular in the fishkeeping hobby. The fish is known for its longevity, beautiful coloration, amazing patterns and markings, and unique shape.
Borneo suckers are bottom dwellers and they enjoy cool, oxygen-rich, swift waters similar to that of their natural habitat, in addition to ample algae and biofilm.
While Borneo suckers may not be the best of aquarium fish due to their aeration demands, they are fairly hardy and easy to care for, and you will enjoy having a few in your aquarium.
Keep reading for more information on the Borneo suckers— we will be talking about their appearance, habitat, behavior, compatible tankmates, and how to care for them in a tank.
Quick Notes about Borneo Suckers
|Dwarf Hillstream loaches, Hillsteam loaches, Butterfly loaches, or Sucker loaches
|Gastromyzon punctulatus (Gastromyzon sp.)
|Tank size (minimum)
|10 gallons (~40 liters)
|up to 3 – 4 cm (~ 1.5 – 2 inches)
|18 °C – 25 °C (65 °F – 77 °F)
|6.5 – 8.0
|2 – 15
|Less than 20
|up to 4 years
|brown, gray with white to yellow dots
Origin of Borneo Suckers
Borneo suckers expressly refer to a group of gastromyzontid loaches that are endemic to Borneo. This group of loaches are classified under the genus Gastromyzon and comprises 36 species.
The name Gastromyzon stems from the Greek words ‘gaster’ — which means ‘stomach’ and ‘myzo’ — ‘ to suckle’.
Gastromyzon belongs to Gastromyzontidae, a family of loaches found in China and Southeast Asia; usually in water bodies with fast currents.
Borneo suckers are arranged in several species groups. The cryptic species in each group share similarities in morphology, though reproductively isolated.
Each group of fish dwells in adjacent river basins but may occur sympatrically. Now, let’s have a look at the groups:
- The Gastromyzon borneensis group: G. borneensis, G. monticola, G. ornaticauda, G. cranbrooki, G. cornusaccus, G. extrorsus, G. introrsus, G. bario
- The G. punctulatus group: G. punctulatus, G. aeriodes, G. katibasensis
- The G. fasciatus group: G. fasciatus, G. praestans
- The G. contractus group: G. contractus, G. megalepsis, G. umbrus
- The G. lepidogaster group: G. lepidogaster, G. psiloetron
- The G. ridens group: G. ridens, G. crenastus, G. stellatus, G. zebrinus
- The G. danumensis group: G. danumensis, G. aequabilis, G. ingeri
- The G. pariclavis group: G. pariclavis, G. emalohensis, G. venustus, G. spectabilis, G. russulus, G. viriosus
- The G. ocellatus group: G. ocellatus, G. farragus
- The G. auronigrus group: G. auronigrus
Habitat of Borneo Suckers
Borneo suckers (Gastromyzon app.) are native to the Borneo region of Southeast Asia (Malaysia: Sabah & Sarawak; Indonesia: Kalimantan Barat, Kalimantan Timur; and Brunei Darussalam: Temburong district).
They inhabit shallow, swift streams and rivers containing clear, cool, and oxygen-rich water.
The habitat is characterized by the abundance of sandy substrates, rocks, gravels, and huge boulders; these are usually slimy as a result of algal growth which serves as their main food source.
The temperature in this area is fairly cool due to the presence of tall trees, on the other hand, submerged vegetation is scarce.
Appearance of Borneo Suckers
Gastromyzon ctenocephalus and Gastromyzon scitulus resemble each other but they can be told apart by the blue markings in the dorsal fin of G. ctenocephalus which are absent in Gastromyzon scitulus.
Also, there are smaller spots on the sides and top body of G. ctenocephalus as opposed to larger spots on the body of G. scitulus. Furthermore, in the G. ocellatus group, G. ocellatus has a single, thick, dark vertical bar that runs across the caudal fin whereas there are two or more bars in the caudal fin of G. farragus.
Gastromyzon species vary in body coloration, for example:
- dark brown in G. ocellatus & G. farragus, G. Ctenocephalus,
- pale grey in G. zebrinus and G. ridens.
Caudal tail color differs too, for example:
- yellow as seen in G. viriosus,
- reddish purple in G. ocellatus,
- blue in G. ctenocephalus.
Note: Under stress, the color fades and the spots become almost indistinguishable.
These species are often 3 – 4 cm in length (1.2 – 1.6 inches) at maturity, while some may grow up to 7 cm (2.8 inches). They possess numerous cream/yellow blotches and spots, or irregular patterns on the top and flanks.
They bear eyes on top of their head, also present is a snout which is broadly round when viewed dorsally, in addition to numerous soft rays. Some species possess a post-oral pouch— this is a pouch-like structure located close to the snout.
Gastromyzon spp. exhibit morphological adaptations to bottom-dwelling in torrential streams and these include depressed head & body, fusion of pelvic fins, and horizontal orientation of paired fins.
These adaptive features form a powerful suction cup that enables them to cling on to rocks and boulders to prevent being swept away by swift water currents. Hence, Borneo suckers are capable of crawling along and feeding off the algae present on the rocks.
Under optimal conditions, Borneo suckers can live up to 3 – 4 years.
Behavior of Borneo Suckers
Borneo suckers are generally peaceful and interactive. They are mostly seen clinging tightly to large rocks in the tank— either relaxing or consuming algae growing on them. Other times, they may be found lying around or climbing the tank glass.
Also, the male Borneo suckers may engage in tussles but actual harm rarely occurs during such bouts.
In the wild, Gastromyzon spp. exist in clusters, so you should try to replicate such grouping by stocking at least 4 specimens. They are interesting and more fun to watch when they socially interact with one another.
They are also very shy and can to hide behind the filer media, decorations, plants, etc.
- Social: Yes
- Active: Yes
- Peaceful: Yes
Feeding Borneo Suckers
Borneo suckers are active algae grazers. They are always on the lookout for benthic algae and biofilm on rocks and other solid surfaces, and this makes up a huge percentage of their natural diet. According to the experiments, they rapidly abandon rocks with reduced algal cover.
In captivity, you can provide meaty foods occasionally to supplement their diet, food options in this category include:
- live or frozen bloodworm,
- vitamin-enriched brine shrimp,
- veggies like blanched spinach, cucumber, and lastly, spirulina.
Ensure that their diet does not contain high amounts of protein to prevent health problems.
The abundance of rich biofilm and algae in a mature aquarium will spare you from sourcing other food items.
Moreover, avoid wiping off algae from the tank walls; except it is growing on the front glass. Be sure to tone up the light intensity and dose the water with fertilizer regularly to promote algae bloom on surfaces, alternatively, one can set up a separate container in a sunlit spot to grow algae on rocks and these can be introduced into the tank later on.
- Diet Type: Omnivore
- Food Preference: Algae and biofilm
- Feeding Frequency: Daily
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Borneo Suckers and Feeding Tip
Some aquarists complain that their Borneo Suckers have a hard time finding the food. I mean it can take them some time before they recognize that algae wafers or blanched vegetables are also good to eat.
If you have the same problem, you can grow algae in a separate bowl.
- You need some kind of transparent container (large soda bottle, spare tank, etc.).
- Fill it with water. Use the water that comes from water changes.
- Put there a lot of small rocks like marble chips and ceramic filter media (The rocks should be clean and aquarium safe, of course).
- Place it next to strong light. Ideally – 24/7.
- To boost growth, you can use any fertilizer to grow plants in a tank.
- Using an airstone will also increase algae growth as well.
- Once you see that rocks are turning green, take a few a place them in the tank to feed
- Return the rocks to the container when they are clean.
At the same time, keep giving them algae wafers and vegetables. Give them time to learn that this can be a food source for them.
There are some reports that Borneo Suckers really like Repashy Soilent Green (check the price on Amazon).
Tank Requirements and Water Parameters
The minimum recommended tank size for housing a single Borneo sucker is 10 gallons (~40 L), however, for about 4 specimens you will need a 20-gallon (80 L) tank or more.
Make sure to cover the top with a tight-fitting lid because the fish is capable of climbing the tank glass.
Temperature: The fish prefer water temperature in the range of 18 °C – 25 °C (65 °F – 77 °F). It can tolerate warmer temperatures but that will decrease the levels of dissolved oxygen. Color fading is a sign that water is too warm for them.
pH: Keep the pH between 6.5 – 8.0 for optimal growth and good health of your fish.
Hardness: Water hardness should be in the range of 2 – 15 dGH, they do not enjoy hard water conditions.
Light is not important for the Borneo suckers. However, lighting is a necessity if you want to encourage the growth of plants and algae on the rocks and other decors present in the tank. In this case, the lighting needs to be bright enough.
The substrate can either be sand or smooth gravel or a mixture of both. Make sure to add rocks— water-worn rocks preferably, and cobbles of varying sizes.
A mixture of substrates will help attain a more natural and visually appealing look. However, avoid sharp or rough substrates that can damage their bodies.
A powerful filtration system needs to be in place to properly aerate the aquarium water and guarantee a high level of oxygenation.
External canister filters with spray bars (for surface agitation) may serve for this purpose, otherwise, additional powerheads can be installed to provide adequate flow and oxygenation of the water.
Moreover, you should aim for a total turnover rate of between 10 – 15 times per hour. Lastly, air stones can equally be added to the tank for more oxygenation.
Be careful, low oxygen in aquarium water can cause lots of problems to your fish. You can read more about it in my article.
In the natural ecosystem, Borneo suckers inhabit rivers and streams where the current is so fast that potential competitors would be washed away. That is why Hillstream loaches have evolved adaptations to stick to the bottom.
Therefore, fast water currents are recommended for tanks housing these fishes.
Plants and Decorations:
Although aquatic plants are pretty much scarce in their natural habitat. Plants like Microsorum pteropus (Java fern) and Anubias spp. can thrive in tanks with the extreme flow, hence they may be added.
Anubias is beneficial to such set-ups because its broad leaves provide cover for tank inhabitants and a surface where algae can attach for the fish’s consumption.
Also, decors such as driftwood, caveworks, and hollow logs are essential because they complement the aesthetics of the aquarium, and also provide feeding ground and hiding spots thereby making the fish more comfortable.
Basic Tank Equipment (links to check the price on Amazon)
Care and Maintenance
Keeping Borneo suckers in a tank is a little bit more complicated if you already do not have some experience in fish keeping. Therefore, I would not recommend these species for beginners.
Keep in mind that Borneo suckers are known to die very easily when first being introduced to a new environment.
That is why it is important to add them only in a well-established tank with sufficient size and water volume to support their need.
Borneo sucker fish will benefit hugely from well-oxygenated tank water and stable water conditions. Additionally, you are required to maintain the water temperature at the right range as warmer temperatures will significantly deplete the levels of dissolved oxygen in the aquarium water, thereby making the fish uncomfortable and unable to function optimally.
Besides, try as much as possible to keep the tank clean always as the fish may not be able to tolerate water with huge amounts of nitrogenous waste. During routine maintenance, do not forget to clean and inspect the filter and other aeration devices.
Maintain good water quality by performing partial water changes; replacing about 25% of the tank water on a weekly basis to prevent excess nitrates build-up.
Sexing Borneo Suckers
Male and females can be distinguished by their physical characteristics.
- The adult females are slightly larger and stouter than the males.
- Additionally, in some species e.g. Gastromyzon ctenocephalus, mature males possess ctenoid tubercles on their heads, and these structures are absent in females.
Breeding Borneo Suckers
Unfortunately, there is little knowledge regarding the captive breeding of Borneo suckers, hence it is safe to assume that Gastromyzon spp. has not been bred in aquaria.
The only information I could find is that a high-protein diet and a slight increase in temperature over 8 weeks. This temperature should be maintained for 2 – 3 weeks and then dropped back to normal. Water flow should be significantly reduced as well.
All these changes will serve as an incentive for reproduction.
Every female can have up to several hundred eggs, depending mainly on female size. They are less than 1 mm in size. The incubation period lasts about 3 days.
Borneo suckers do not have parental instincts. Once they lay them, they leave them.
The fry are extremely sensitive to water quality, any, even minor pollution will negatively affect their well-being and can lead to the death of the entire brood.
Borneo Suckers and Suitable Tankmates
It makes a lot of sense to keep Borneo suckers together with tank mates that are relatively small, quiet, peaceful and can share the same water parameters with them. They are great candidates for community tanks that don’t contain large species of fish and other animals.
Suitable tankmates for Borneo suckers are particularly non-aggressive fish such as surface-dwelling Barbs, and Rasboras, Mountain minnows, Gobies, Swordtails, Pygmy Cories, Otocinclus Catfish, Panda Garra, etc.
– Dwarf shrimp:
If you are planning to keep Borneo suckers with dwarf shrimp, you should understand there is a chance they may eat shrimplets even accidentally since baby shrimp are so tiny. So, if you are serious about breeding dwarf shrimp, I would not recommend taking any risk.
If you are thinking about adding shrimp to the tank, I would definitely recommend looking at Vampire shrimp and Bamboo shrimp. The point is that these shrimp are filter-feeders and also need high water flow. They will be one of the best companions for Borneo suckers.
– Freshwater Snails
Endlers can share the same tank with any type of freshwater snails (for example, Japanese trapdoor snails, Ramshorn snails, Nerite snails, Malaysian Trumpet snails, Black Devil Snails, Asolene spixi, Rabbit Snails, etc.).
Buying Borneo Sucker
Borneo sucker fish is readily available for sale in local fish stores and a single specimen retails at $10 – $15 depending on the species. Most specimens on display are labelled as G. borneensis, though this is unlikely to be true since the species is a rarity.
Moreover, you should be aware that Borneo sucker fish are often imported in a stressed and emaciated state. So once you purchase the fish, provide a well-oxygenated and algae-rich environment to hasten its recovery or else it won’t survive.
If you are searching for a small, eye-catching, and unusual fish species for your aquarium, then the Borneo sucker is ideal for you. This fish is a peaceful bottom dweller and it packs a whole lot of personality.
Furthermore, it is best to keep Gastromyzon spp. in groups of 4-6 specimens for them to exhibit social behavior in the tank.
Be sure to provide a steady supply of algae and meaty foods, and also maintain sufficient levels of dissolved oxygen in the aquarium to encourage healthy growth and longevity of your Borneo sucker fish.