The blue botia, also known as yasuhikotakia modesta, is a beautiful loach species with a distinct heavy body build.

It comes in exciting hues of red, yellow, orange, and blue that add spark and life to your otherwise bland aquarium. Learn more about this nocturnal fish in this article.


Scientific Name Yasuhikotakia modesta
Origin Southeast Asia
Common Names Redtail Botia, Blue Loach, Redtail Blue Loach, red-finned Loach
Family Botiidae
Care Level Intermediate
Minimum Tank size 55 gallons
pH 6.0 – 7.5
Hardness 8-12 dGH
Temperature 72 – 86 F
Feeding Omnivore
Reproduction Egg layer
Average Lifespan 5 years
Average Size 7 inches
Temperament Semi-aggressive


The Redtail Blue Loach is commonly found in Northeastern India, Vietnam, Thailand, Cambodia, and the Malaysian Peninsula. They are widely distributed; thus, even with the high demand of this species, they do not suffer from any threat of extinction.

Blue loaches tend to favor large rivers and flooded fields with muddy bottoms and lots of trees. They often migrate to spawn during flooding season and return once the waters have receded. This fish is nocturnal, preferring to hide out in rocks and tree roots during the day and only emerging at night.

They are known by so many other names, thanks to the variation in their color forms. These common names include Redtail Botia, Blue Loach, Orange-finned Loach, Blue Redtail loach, Redtail Loach, etc.


The Blue Botia has an elongated body that comes in the most exciting hues. Its body is heavily built and arched. In many ways, Blue Botias look a lot like other loach species. Their body is a fascinating shade of bluish-silver that almost looks grey.

The juvenile Blue Botia has a greenish hue that makes telling them apart from the adult fish easy. The young fish sometimes has a more intense green accented by dark stripes that run down the length of their body. These dark bars disappear as they reach maturity. You can identify healthy fish by their bright hues.

Like all Loach fish species, Blue Botias have four pairs of barbels protruding from their mouths. Their fins are red, orange, or sometimes yellow. Even though they are regarded as scaleless fish, they have tiny scales on their body.

– Sexual Differences

Not much difference exists between the male and female Blue Botias. The only noteworthy difference is in their size. Male Blue Botias are smaller and slimmer than their female counterparts.

– Size

The average blue botia size is around 10 inches in the wild with proper care and nutrition. However, in captivity, they seldom reach seven inches.

– Lifespan

Blue botia lifespan, on average, is around five years with proper care. We will show you how best to care for this fish species so that they live an active, happy, and healthy life.


Blue redtail loaches are hardy and quite resistant to diseases. However, they are not suited for beginners because they need to be kept in pristine water conditions.

They are almost scaleless, exposing them to many freshwater diseases and making them very sensitive to the OTC medications used to tackle the diseases.

To get the most out of this fish, you will require vital knowledge and experience in taking care of scaleless fish.

Tank Setup

When setting up a tank for Blue Loaches, you must be deliberate about creating an environment similar to their natural habitat. Another thing to remember during the tank setup for this fish is that they must never be introduced to biologically immature tanks. The consequences can be fatal.

– Tank Size

For juveniles, you should have at least a 55-gallon tank and 75-gallons for the adult species. They need lots of room to swim in, so the more significant the tank you house them in, the better. Ensure that your tank has a tight cover; if not, these avid jumpers will leap out of your tank.

– Filtration

Seeing as this fish loves pristine water conditions, it is only logical that your tank is equipped with an efficient filtration system. That way, you can rid the tank of the nasty buildup before it becomes a significant issue. An under gravel filter is an excellent choice for this species as they clear out the tank and improve the concentration of oxygen in the water.

– Substrate

In its natural habitat, this fish has lots of mud as the substrate. An alternative substrate for these loaches is sand and gravel, which allow this fish to burrow in. Another reason sand and gravel are excellent substrates for your fish tank is that they are not harsh on the fish abdomen, thanks to their smooth surface.

– Tank Decorations

The ideal tank for Blue Loaches is one with lots of spaces for them to hide out in. You can create hiding spots with caves, upturned clay pots, rocks, and dark areas. Plastic tubes and flower pots also make excellent hiding spots for your fish. With more hiding places, you will experience less aggression with this Loach species.

Another thing to consider in your tank setup is trees. Be sure to provide your fish with hardy trees and roots that they can take cover in and lay their eggs.

– Water Requirements

Redtailed blue loaches thrive in pristine water that has the correct water parameters. They prefer slightly warmer waters, with temperatures around 72 – 86 F. Their tank water should be slightly acidic and moderately hard.

– Lighting

Your tank should be dimly lit to cater to the redtail Blue Loach’s nocturnal behavior. To this effect, we advise that your only place is trees that can survive this condition in your tank. Great options include: Java moss, Anubias spp, and Javafarn.


Blue loaches are omnivores, feeding on both plants and animals. Their diet is primarily composed of worms, insects, and small crustaceans like shrimps in the wild. Consequently, they are not picky eaters; they will literally eat anything you place in front of them. Regardless, the onus lies on you to ensure that they are fed high-quality foods.

You can feed them with live, frozen, or commercial food, whichever works best for you. To maintain a healthy balance, we suggest that you provide them with high-quality tablets or flake food daily. You can try daphnia, tubifex, bloodworms, micro worms, and vegetable foods like algae wafers.

– Feeding Frequency

We recommend that you provide these Blue Loaches with high-quality food rich in protein at least twice daily. Remember to keep their portion size small; you want to aim for quantities that they can consume in three minutes or less. That way, you can avoid overfeeding your loaches.


The redtail Blue Loach is a semi-aggressive fish that prefers to swim at the bottom of the fish tank. They are more active at night, choosing to lounge and hide out during the day.

When excited, they make a clicking sound that helps them communicate with each other.

They are often aggressive to fish with a similar appearance. The Botia Loach has an alpha male that controls the other fish in its clique. To reduce the aggression between these species, we recommend that you house them in a large tank filled with hiding spots.

Blue loaches prefer to be kept in small groups of at least six. When they are raised singly, they start to exhibit signs of depression, becoming withdrawn. They also become overly aggressive.

Tank Mates

The tank mates you choose to add to your Loaches tank greatly influence its health and activity. Since this fish is a schooling fish, it should not be kept by itself in a tank. We recommend a schooling size of at least half a dozen fish.

As a rule of thumb, Botia Loaches should not be raised with small, slow-moving fish with calm temperaments like the Goldfish. They will torment them and may even eat those small enough to fit in their mouth.

We recommend other large, active fish with a similar temperament. Examples are Zebrafish, Glowlight tetra, Tinfoil Barb, Gouramis, semi-aggressive cichlids, and Tiger Barb.


Red-tailed loaches are seasonal migrants, moving to other water bodies to spawn. For this reason, their spawning process in captivity is very complicated, with little or no success being recorded. Most of the species sold in pet stores were either caught in their natural habitat or bred using complicated hormonal stimulations.

Tips To Keep Your Blue Loach Healthy

  • Make sure your tank is big enough to house this fish
  • Ensure that you vacuum the vacuum with each water change
  • Change at least 50 percent of the tank water weekly to remove waste and leftover food
  • Ensure your tank has an efficient filtration system, preferably a low-level one
  • Do not introduce your fish to a biologically immature tank
  • Fill up your tank with enough hiding spots
  • Plug small holes where your loach can get stuck in with aquarium silicone sealant


  • Blue Botias are semi-aggressive schooling fish
  • With adequate care, they can live for up to five years
  • Like other loaches, they are nocturnal

Blue Botias are perfect for aquarists with some knowledge of caring for scaleless fish. They are seasonal migrators and are thus challenging to breed in captivity. However, with our tips, you can succeed in raising this delightful loach species. We’d love to hear from you; leave us a comment.

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