Rasboras feel safer being together; in the wild, they are mostly found in schools. In aquariums, they may swim in a school, where all fish movement is coordinated in the same direction, or in a shoal, where swimming is social interaction, and they swim freely but close to each other.
Let’s look at rasboras’ schooling and shoaling behavior. We will list rasboras and other species that may school or shoal together, discuss reasons for rasboras to stop schooling, and the effect of overstocking on these gentle yet hardy fish.
Are Rasboras Schooling Fish?
Rasboras move in schools because being part of a community adds to their sense of safety. When they move in a school, rasboras’ movement is coordinated, and they move in a single cloud-like formation that shifts and changes all the time.
Schools do not have a leader. They form and reform as they move.
Why Do Rasboras School Together?
Rasboras prefer moving in schools, especially when they do not feel safe, as the school protects them from predators. While swimming as a school, each fish’s chances of being caught get smaller as the group grows larger.
Rasboras may also find it easier to defend themselves, and, when spawning, the sheer number of eggs means that each egg has a better chance of survival.
Moving in schools helps their foraging, as it becomes easier to find food. Many eyes point in all directions, and once even a single fish detects, all rasboras will shift toward the feeding source as a single, coordinated mass.
When moving in schools, rasboras swim more efficiently and conserve energy by keeping close to each other and reducing friction, allowing them to sense each other’s movements and maintain coordination in all their moves.
Staying close together also means that rasboras have better chances of finding a mate.
Will Different Rasboras School Together?
Different Rasboras do school together.
No hard and fast rule is applicable here, as fish interaction depends on the environment, the type, and the size of the aquarium.
The number of Rasboras is also crucial, too-small a number will make some fish feel unsafe and prevent them from schooling with others, while too large a number may overcrowd the aquarium and drive the fish away from each other.
There are over 350 types of rasbora; the top ten types of these which are suitable for home aquariums are the Blackline, Chili, Clown, Exclamation Point, Fire, Glowlight, Harlequin, Neon Green, Galaxy, Clown, Dwarf, Lambchop, Brilliant, and Phoenix Rasboras.
These will get along with each other well, as long as a suitable aquarium provides a safe and livable environment.
Do Rasboras School With Other Fish?
Rasboras are gentle shoaling fish who are likely to get along beautifully with other fish. A community tank offers a colorful experience if the fish you choose can school and shoal side by side.
The harlequin, the most popular and commonly kept rasbora, and other popular species will live alongside similar-size, non-predatory fish.
Keeping at least ten rasboras together is recommended to keep them happy.
Rasboras are related to koi, goldfish, and barbs. They will school happily alongside guppies, platies, cory catfish, small barbs, dwarf and chocolate gouramis, danios, small and neon tetras, and other small-sized rasboras.
Other species you may add to your rasboras are nano fish, shrimp, and snails.
Which Rasboras School Best?
While all rasboras are excellent schoolers, some species will find it easier to get along with others. This is especially important for beginners, but seasoned tank owners will also enjoy a thriving schooling community.
Two such species are the harlequin and the lambchop rasboras.
Harlequin rasboras are among the world’s most popular species of schooling fish because they are attractive and sociable.
When kept in groups of 8 to 10 fish, harlequins will fit in easily with other fish. In large groups, male harlequin rasboras offer their most colorful presentation to attract female harlequins.
They make excellent tank mates with other same-size and non-predator fish, including bettas and lambchop rasboras.
The Lambchop rasbora’s name comes from a black, triangle-shaped patch on its back.
This patch is also responsible for the “fake harlequin” nickname since harlequin rasboras have a bluish-black triangular patch on their back.
These are very hardy fish that do not require specialized care or pampering. Lambchop Rasbora will stress when placed in small groups and must be kept in groups of 8 to 10 fish to thrive.
Why Won’t My Rasboras School?
Rasboras are known to be shoaling fish that schools naturally, especially in larger numbers of 8 to 10 groups.
This natural form of grouping and socializing makes schooling rasboras the perfect candidates for a community and a single-species tank. However, these natural-born schoolers sometimes shy away from each other and move in small groups or on their own.
Non-schooling rasboras are likely to cause concern. Is there something wrong with them? Are they unhappy with the environment, ill, or maybe threatened by other fish?
The rule of thumb is that fish move in schools for safety. In the wild, fish constantly move in schools to protect themselves from predators.
If your rasboras do not school, it probably means they feel safe. The tank offers a good environment for them to thrive in, their numbers keep them from feeling stressed, and the mates you chose for them pose no threat.
This may disappoint tank owners, who chose schooling fish because they want to see their pets moving as one, in incredible unison.
Another reason for non-schooling rasboras may be that there are too few of them, and you should increase their number to between 8 and 10 fish per group.
If you plan to add fish to the tank, make sure the tank is big enough for the fish. While understocking may cause schooling fish to stress, overstocking is just as stressful.
Is My Schooling Fish Tank Overstocked?
Overstocking a fish tank with plants, decorations or fish creates an unhealthy environment that is harmful and stressful to your rasboras. Overstocking causes us many fish deaths due to environmental conditions or eating habits.
Here are a few signs that your schooling fish tank is overstocked.
Murky water: If your tank water remains murky after cleaning it, it may be overstocked. Your best course of action is getting better filtration and reducing the number of fish in the tank.
An increased occurrence of algae: While some algae are always present in fish tanks, an increased occurrence of algae may indicate, among others, an imbalance of nutrients in the water. Overstocking may be the cause of such an increase in nutrients. Apply fish reduction and antialgae treatment.
Insufficient filtration: If the bottom of your tank is filled with waste, this may mean that your filtration system is unable to cope with the waste in your fish tank.
If this is a new occurrence, it may mean that your fish tank is overstocked. Reducing the number of fish and getting a more powerful filtration system will improve waste filtration.
Not enough oxygen: Oxygen levels in an overpopulated fish tank may be dramatically reduced. Fish respond to low oxygen levels by moving to the oxygen-rich surface of the water, gasping, exhibiting fast breathing, and swimming listlessly or off-balance.
Fish number reduction will improve oxygen levels.
Territory-based aggressive behavior: Rasboras are not overly territorial. Normally, they shoal or school with their species and other fish with no sign of aggression.
If your rasboras become aggressive and nip at other fish’s tails or fins, or if they shy away from other fish or display injuries, your fish tank may be overstocked.
Schooling rasboras attack other fish to assert their dominance when they feel the need to compete for territory, food, and mates.
If your rasboras feel crowded, underfed, or outnumbered by sexual competitors, they may try to assert their dominance through aggression. Reducing the number of fish or opting for a larger tank may solve the problem.
Rasboras are friendly and gentle schooling and shoaling fish. They enjoy the company of other species of rasboras and various same-size, non-predatory fish. These attractive, hardy fish are an excellent choice for a community fish tank and are highly recommended for both beginners and experienced fish tank owners.